Term
| __ are the basic structural and functional unit of the body |
|
Definition
|
|
Term
Cells can be divided into two major compartments:
-The __, the part of the cell located outside of the nucleus, and
-The __, the largest organelle within the cell. |
|
Definition
|
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Term
The cytoplasm
-Contains __ and __ arranged in an aqueous gel called the __.
-The __ (previous) consists of solutes including __ (Na+, K+, Ca2+) and organic molecules such as __, __, __, __, and __.
-The cell controls the concentration of __ within the cytoplasmic compartment, which influences the rate of __ within the cell. |
|
Definition
- organelles; inclusions; cytoplasmic matrix
- cytoplasmic matrix; inorganic ions; metabolites; carbohydrates; lipids; proteins; RNAs
- metabolites; metabolic activity |
|
|
Term
the nucleus
-Contains the genome and enzymes necessary for __ and __. |
|
Definition
| - dna replication; rna transcription |
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Term
| All cells have the same basic set of -organelles which can be classified into two groups: __ and __ |
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Definition
| - membranous (membrane bound) organelles; nonmembranous organelles |
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Term
- Membranous (membrane bound) organelles that have plasma membranes separating their __ from the __
- Nonmembranous organelles that lack __.
- The spaces enclosed by the organelle membranes make up the __ in which __, __ and other __ are segregated or concentrated |
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Definition
- internal environment; cytoplasm
- plasma membranes
- intracellular microcompartments; substrantes; products; substances |
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Term
-__ are structures or substances that are not surrounded by a __.
-They can consist of crystals, pigment granules, lipids, glycogen, and other stored __. |
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Definition
- inclustions; plasma membrane
- waste products |
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Term
-The plasma membrane is now actually classified as a __.
-It is a __ barrier.
-Maintains cell __.
-Regulates __ interactions.
-Carries out specific recognition functions via __ and __.
-Establishes __ for specific molecules.
-Transduces physical or chemical signals into __. |
|
Definition
- membranous organelle
- selectively permeable
- structure
- cell-cell
- receptors; antigens
- transport systems
- intracellular events |
|
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Term
Plasma membrane
-The current interpretation of the molecular organization of the plasma membrane is now referred to as the __.
-The membrane consists primarily of __, __, and __.
-The phospholipids form a __, with __ properties (it is both hydrophobic and hydrophilic).
-The fatty acid chains of the __ face each other and create a __ domain.
-The surfaces of the membrane are formed by the __ of the phospholipids and create a __ domain. |
|
Definition
- modified fluid mosaic model
- phospholipids, cholesterol, proteins
- lipid bilayer; amphipathic
- phospholipids; hydrophobic
- polar heads; hydrophilic |
|
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Term
Plasma Membrane
-__ account for approximately half of the total membrane mass in most membranes.
-Most of the proteins embedded in the membrane span the lipid bilayer __; these proteins are the __
-__ are not embedded in the membrane and are associated with the membrane by strong __, mainly with __. |
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Definition
- proteins
- completely; integral proteins
- peripheral membrane proteins; ionic; integral proteins |
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Term
-Carbohydrates may be attached to the proteins on the extracellular surface of the membrane, forming __.
-Carbohydrates can also be attached to the lipids, forming __.
-These surface molecules make up a layer on the cell surface that is referred to as the cell coat or __.
-__ and __ have specific functions in metabolism, cell recognition, cell association, and serve as receptor sites for hormone |
|
Definition
- glycoproteins
- glycolipids
- glycocalyx
- glycoproteins; glycolipids |
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Term
glycocalyx
-The __ can be seen projecting from the microvilli of this absorptive cell from the intestine.
-Glycoproteins here include digestive enzymes such as __ and __ |
|
Definition
- glycoproteins
- dipeptidases; disaccharidases |
|
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Term
-Microdomains of the plasma membrane known as __ control the movement and distribution of __ within the lipid bilayer.
-Recent research has indicated that the distribution and movement of proteins within the lipid bilayer is not as random as was once believed.
-Localized regions within the plasma membrane contain high concentrations of __ and __, called __.
-The __ (previous) is __ and exhibits less __ than the surrounding membrane.
-The diminished fluidity is due to the presence of __ and the presence of longer, highly __ |
|
Definition
- lipid rafts; proteins
-
- cholesterol; glycosphingolipids; lipid rafts
- lipid raft; thicker; fluidity
- cholesterol; saturated fatty acid chains |
|
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Term
-Lipid rafts contain various integral and peripheral proteins involved in __.
-Each raft is equipped all of the elements necessary to receive and convey __.
-These elements include receptors, coupling factors, effector enzymes, and substrates.
-__ in lipid rafts occurs more rapidly and efficiently because of the close proximity of the __. |
|
Definition
- cell signaling
- specific signals
-
- signal transduction; interacting proteins |
|
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Term
-Integral membrane proteins can be visualized by a special technique known as __.
-When tissue is prepared for electron microscopy, membranes typically split along the __ plane.
-This exposes the two faces of the membrane, the __ and the __.
-The __ is backed by the extracellular space, while the __ is backed by the cytoplasm
-Usually the P-face displays more __ than the E-face. |
|
Definition
- freeze fracture
- hydrophobic
- E-face; P-face
- E-face; P-face
- particles (i.e. proteins) |
|
|
Term
-__ have important functions in cell metabolism, regulation, and integration.
-There are __ broad categories of membrane proteins that have been defined.
-The categories are not mutually exclusive, meaning that a structural membrane protein may simultaneously act a receptor, an enzyme, a pump, or any combination of these functions |
|
Definition
-integral membrane proteins
- six |
|
|
Term
-__ – transport ions such as Na+ across the membrane as well as macromolecule precursors.
-__ – allow the passage of small ions, molecules, and water across the membrane in both directions. __ are a type of channel (more on that later).
-___ – allow recognition and localized binding of ligands in processes such as hormonal stimulation, coated-vesicle endocytosis, and antibody reactions |
|
Definition
- pumps
- channels; gap junctions
- receptor proteins |
|
|
Term
-__ – anchor the intracellular cytoskeleton to the extracellular matrix. Examples of these include the __ that link cytoplasmic actin to an extracellular matrix protein (fibronectin).
-__ – include ATPases involved in ion pumping, ATPase synthase in the inner mitochondrial membrane, and digestive enzymes such as dipeptidases and disaccharidases.
-__ – visualized by the freeze fracture method, especially where they form junctions with neighboring cells. |
|
Definition
- linker proteins; integrins;
- enzymes
- structural proteins |
|
|
Term
-Substances that either enter or exit must pass through the __.
-Some substances (__ and small, __) cross the membrane by __.
-All other molecules require ___ to provide them with a passage. |
|
Definition
- membrane
- (fat soluble and small, uncharged molecules); simple diffusion
- membrane transport proteins |
|
|
Term
-__ – transfer small, water-soluble molecules.
-They are very __ and often transport only one type of __.
-After binding to a molecule that will be transported, the carrier protein undergoes __ and releases the __ on the other side of the membrane.
-Some carrier proteins such as the __ pump require energy for the active transport of substances against their concentration gradient.
-Other carrier proteins, such as glucose carriers, do not require energy and participate in __ |
|
Definition
- carrier proteins
- selective; molecule
- conformational changes; molecule
- sodium postassium
- passive transport |
|
|
Term
-__ – also transfer small, water-soluble molecules.
-Channel proteins create __ through the plasma membrane that regulate the __ of the molecule.
-Channel protein transport can be regulated by membrane potentials (voltage-gated ion channels in neurons), __ (ligand-gated ion channels such as acetylcholine receptors in muscle cells), or __ (mechanically-gated ion channels in the inner ear). |
|
Definition
- channel proteins
- hydrophilic channels; transport
- membrane potentials, neurotransmitters; mechanical stress |
|
|
Term
-__ maintains the integrity of the plasma membrane and provides for the transfer of molecules between different cellular compartments.
-This process involves __ in the plasma membrane at localized sites and the subsequent formation of __ or fusion of vesicles with the membrane.
-Vesicular transport can be described in more specific terms __ and __ |
|
Definition
- vesicular transport
- configurational changes; vesicles;
- endocytosis; exocytosis |
|
|
Term
| __ brings molecules and other substances into the cell that would otherwise be too large to pass through the membrane |
|
Definition
|
|
Term
-__ is essentially the reverse of endocytosis
-A vesicle moves from the __ to the __ where it discharges its contents to the __ |
|
Definition
- exocytosis
- cytoplasm; plasma membrane; extracellular space |
|
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Term
receptor mediated endocytosis
-When ligands bind to their receptors, the receptors become __ into __.
-The coated pit __ and forms a __ that transports the __, into the cell.
-The coated vesicles fuse with __, a system of vesicles and tubules located in the cytosol near the cell surface.
-The __ in the endosomes allows for the separation of the __ and their receptors.
-Ligands are typically sent to __, while their __ are returned to the __. |
|
Definition
- aggregated; coated pits
- invaginates; coated vesicle; ligand
- endosomes
- low pH; ligands
- lysosomes; receptors; cell membrane |
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Term
- __:Small invaginations of the cell membrane form to trap extracellular fluid and any molecules contained in that fluid.
-- sometimes referred to as __
- __: this literally means cell eating
--Certain cells such as __ and polymorphonuclear leukocytes are specialized for engulfing and removing bacteria, protozoa, fungi, damaged cells and other cellular trash. |
|
Definition
- pinocytosis
-- cell drinking
- phagocytosis
-- macrophages |
|
|
Term
- __:These organelles are sites of intracellular digestion and turnover of cellular components
- __ (previous) are membrane bound vesicles that contain a variety of __
-The __ of lysosomes are resistant to the hydrolytic digestion that occurs inside the organelle
- the most common enzymes are __, __, __, and __
-These enzymes are responsible for the degradation of macromolecules derived from __ pathways and __ (removal of organelles |
|
Definition
- lysosomes
- lysosomes; hydrolytic enzymes
- membranes
-proteases, nucleases, lipases, and phospholipases.
- endocytotic ; autophagy |
|
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Term
Lysosomal function
-Synthesized in the __; their enzymes are packaged in the __
-Contents of secondary lysosomes can be __ or can remain in the cell as __.
- in some cells, __ can be excreted |
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Definition
- RER; golgi complex
- excreted; residual bodies
- lysosomal enzymes |
|
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Term
Lysosomal Storage Diseases
- Lysosomal diseases are caused by __
- The result is an accumulation in cells of __ used in __
- there are __ lysosomal storage diseases |
|
Definition
- defective lysosomal enzymes
- specific substrates; lysosomal enzymatic reactions
- 49 |
|
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Term
-Children born with lysosomal storage diseases usually appear __ at birth, then clinical signs of disease begin to appear
-These children grow __, show changes in __, and develop bone and joint deformities leading to __.
-They may loose already attained skills such as __ and __
- __ and __ may occur
-These children are prone to __ infections, __ disease, and __ of internal organs, such as the liver and spleen (hepatosplenomegaly). |
|
Definition
- normal
- slower; facial features; restrictions of limb movements
- speech; learning ability
- behavioral problems; mental retardations
- lung; heart; enlargement |
|
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Term
-____ is characterized by the deficiency of β-hexosaminidase, which results in the accumulation of gangliosides in the central nervous system.
- the accumulation of __ interferes with the normal functioning of cells |
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Definition
- tay-sachs disease
- gangliosides |
|
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Term
| -The most common lysosomal storage diseases are __, __, and __ |
|
Definition
| - gaucher disease; hunter syndrome; pompe disease |
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Term
-Gaucher disease – characterized by the defective activity of a __, which results in the accumulation of __ in the __, __, and __.
-Gaucher disease is now treated with __. |
|
Definition
- glucocerebrosidase;glucocerebrosides; spleen; liver; cns
- enzyme replacement therapy |
|
|
Term
-__ consist of two subunits that are composed of four types of rRNA and almost 80 different proteins.
-The RNA of both subunits are synthesized in the __.
-Subunits leave the nucleus via __
-Ribosomes play an important role in translating __ in protein synthesis |
|
Definition
-ribosomes
- nucleus
- nuclear pores
- mRNA |
|
|
Term
-Individual ribosomes are held together by a strand of __ to form __.
-__ synthesized for use in the cytoplasm are synthesized on polyribosomes existing as isolated clusters in the cytoplasm.
-Polyribosomes attached to membranes of the __ translate __ that code for proteins that are secreted or stored in the cell. |
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Definition
- mRNA; polyribosomes
- proteins
- ER; mRNAs |
|
|
Term
- __:This is a membrane system that consists of interconnected sacs and channels that enclose a space called the __
-There are two types:
1.__ – cytosolic side is covered with polyribosomes
2.__ – lacks associated polyribosomes |
|
Definition
- endoplasmic reticulum; cisterna
-
1. rer
2. ser |
|
|
Term
ser is involved in the following processes
1.
2.
3.
4. |
|
Definition
1. steroid and lipid metabolism
2. glycogen metabolism
3. membrane formation and recycling
4. detoxification and conjugation of noxious substances |
|
|
Term
| SER is specialized in __, where it is called the __; responsible for sequestering __. |
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Definition
| muscle; sarcoplasmic reticulum; calcium |
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Term
-The function of the __ is to complete posttranslational modifications, package and place an address on products synthesized by the cell.
-It is composed of smooth membrane-limited __ that appear as flattened sacs. |
|
Definition
- golgi apparatus (complex)
- cisternae |
|
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Term
golgi apparatus
-The cis or forming face receives several types of molecules produced in the __.
-After processing, these molecules are released from the __ face in larger vesicles that constitute __, lysosomes or other cytoplasmic components |
|
Definition
- RER
- trans; secretory granules |
|
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Term
-__ is a rare inherited disorder characterized by poor physical growth and mental retardation.
-It is caused by a deficiency of __, a phosphorylating enzyme, normally present in the Golgi Apparatus.
-__ are not separated to form lysosomes and are secreted.
-The __ of these patients are empty.
-Cells show large __ granules that interfere with cellular metabolism. |
|
Definition
- I-cell disease (inclusion cell disease)
- phosphotransferase
- nonphosphorylated proteins
- lysosomes
- inclusion |
|
|
Term
-__:The organelle that transforms the chemical energy of metabolites in the cytoplasm into energy for the cell.
-Around 50% is stored as high energy phosphate bonds in __.
-The remaining 50% is dissipated as __ for body temperature maintenance.
-This organelle has a __ membrane.
-Mitochondria also have __ DNA. |
|
Definition
- mitochondria
- atp
- heat
- double
- circular |
|
|
Term
-Mitochondria contain the enzyme system that generates ATP via the __ and __.
-__ is a large membrane-bound enzyme found in the inner mitochondrial membrane. |
|
Definition
- citric acid cycle (krebs cycle); oxidative phosphorylation
- ATP synthase |
|
|
Term
-__ is found in the inner mitochondrial membrane.
-This membrane has a series of infoldings called __. |
|
Definition
|
|
Term
-Mitochondria are transmitted by the __
-Both males and females can be affected by mitochondrial diseases, but __ can not transmit the disorder.
-__ do not transmit mitochondria at fertilization. |
|
Definition
- mother (maternal inheritance)
- males
- males |
|
|
Term
mitochondrial diseases
- MERRF: __
- this disease is characterized by generalized __, loss of __, and multiple ___
- the major complications are __ and __ because the __ and __ muscles are affected
- histologically, __ appear ragged due to aggregations of abnormal __ |
|
Definition
- myoclonic epilepsy with ragged red fibers
- muscle weakness; coordination (ataxia); seizures
- cardiac; respiratory failure; cardiac; respiratory
- red muscle fibers; mitochondria |
|
|
Term
There are three maternally inherited mitochondrial diseases that affect males more severely than females:
1.
2.
3. |
|
Definition
1. Leber's hereditary optic neuropathy (LHON)
2. male infertility
3. pearson marrow-pancreas syndrome |
|
|
Term
leber's hereditary optic neuropathy
-__ of the affected individuals are male.
-The disease is confined to the __.
-Affected individuals suffer a sudden loss of vision in the __ of life |
|
Definition
-85%
- eye
- second and third decades |
|
|
Term
male infertility
- almost all the energy for sperm motility is derived from __ |
|
Definition
|
|
Term
pearson marrow pancreas syndrome
- __ and __ observed in childhood |
|
Definition
| - anemia; mitochondrial myopathy |
|
|
Term
- peroxisomes: __ shaped organelles.
-Peroxisomes oxidize specific organic substances by removing __ ions and transferring them to oxygen. This process produces __, an extremely toxic substance.
-__, an enzyme that breaks down hydrogen peroxide, is contained within peroxisomes.
-Peroxisomes also contain __ and __ involved in lipid metabolism |
|
Definition
- spherically
-hydrogen; hydrogen peroxide
-catalase
- d-amino acid oxidases ;beta oxidation enzymes |
|
|
Term
-Peroxisomes in the liver perform a variety of __ processes.
-Peroxisomes in liver cells (hepatocytes) are responsible for the detoxification of __ by converting it to __.
-Peroxisomes are abundant in the __ and __ (they are found in other cells, too).
-The number of peroxisomes can __ in response to diet, drugs, and hormonal stimulation. |
|
Definition
- detoxification
- alcohol; acetaldehyde
- liver; kidney
- increase |
|
|
Term
| There are various disorders caused by the inability to import proteins into __ because of faulty targeting signals or receptors |
|
Definition
|
|
Term
-Zellweger syndrome is the most commonly inherited peroxisomal disease.
-Zellweger syndrome is a rare, __ disease that is lethal within the __ of life.
-The syndrome belongs to a group known as the __, that affect __ formation in the axons of the brain.
-Zellweger syndrome is characterized by a reduction or absence of peroxisomes in __, and cells of the __ and __ |
|
Definition
- zellweger syndrome
- congenital; first year
- leukodystrophies; myelin
- hepatocytes; kindney; brain |
|
|
Term
zellweger syndrome
-Zellweger syndrome is caused by the mutation of the __, which encodes the receptor for the peroxisome targeting signal (it does not recognize the Ser-Lys-Leu at the carboxy-terminus of enzymes directed toward peroxisomes).
-The clinical characteristics include __, high levels of __ and __ in the blood, and defective __.
-Children may be unable to __ or __ or __ |
|
Definition
- PXRI gene
- hepatomegaly (liver enlargement), iron; copper; vision
- move; suck; swallow |
|
|
Term
-The __ is a complex network of microtubules, actin filaments (microfilaments) and intermediate filaments.
--Helps maintain the __ of the cell, plays a role in the __ of organelles and vesicles and also participates in the movement of entire cells.
-__ help move organelles.
-__ functions include anchoring and movement of membrane protein, formation of the structural core of microvilli, cellular locomotion, extension of cell processes.
-__ have a general support or structural role |
|
Definition
-cytoskeleton
-- shape; movement
- microtubules
- actin
- intermediate filaments |
|
|
Term
Kartagener's syndrome
-Defects in the organization of __ and microtubule-associated proteins can immobilize __ of the respiratory epithelium.
-Accumulated secretions and mucus cannot be cleared causing __
-Dysfunction of microtubules can cause problems with __ in men, which can cause infertility because the flagella are affected.
-In women, __ in the uterine tubes can cause infertility.
-In addition, __ of internal organs may be seen in individuals with Kartagener’s syndrome.
-This side reversal is called __. |
|
Definition
-microtubules; cilia
- chronic respiratory infections
- sperm motility
- ciliary transport of the ovum
- side reversal
- situs inversus |
|
|
Term
- __:Membrane-limited compartment that contains the genome
-- components include: __, __, __, and __ |
|
Definition
- nucleus
-- chromatin; nucleolus; nuclear envelope; nucleoplasm |
|
|
Term
-Chromatin: Complex of __ and __
-In non-dividing cells, the chromatin is in various degrees of __ or __
- the degree of condensation results in two kinds of chromatin observed by light and electron microscopy, these are __ and __ |
|
Definition
- dna; proteins
- coiling; condensation
- heterochromatin; euchromatin |
|
|
Term
- heterochromatin
--is the __ form
-- on EM looks like ___
-- on LM looks like __
- euchromatin
-- is the __ form
-- on EM looks like __
-- on LM looks like __ |
|
Definition
-
-- more condensed form
-- coarse electron dense granules
-- basophilic clumps
-
-- less condensed
-- finely dispersed granular material
-- lightly stained basophilic areas |
|
|
Term
chromatin structure
- __ is the basic structural unit
-- 2 loops of __ wrapped around a core of __ with a linking __
-- beads on a string
- __ chromatin fibril
-- __ coiled around an axis
-- __ per turn |
|
Definition
- nucleosome
-- dna; 8 histone proteins; 2nm filament of dna
- 30 nm
-- nucleosomes
-- six nucleosomes |
|
|
Term
chromosomes: human cells
- humans have __ chromosomes, arranged in __ homologous pairs.
-- the pairs can be divided into __ pairs of autosomes and __ pairs of sex chromosomes
- 46 chromosomes is the __ number
- dna content of the __ chromosomes |
|
Definition
- 46; 23
-- 22; 1
- diploid (2n)
- diploid (2d) |
|
|
Term
-Chromosomal structure can be studied by examining stained __
- ___: Chromosomes sorted by size, shape, and staining pattern
--Can reveal __ in chromosome number or structure |
|
Definition
- metaphase chromosomes
- karyotype
-- alterations |
|
|
Term
- sex chromatin: Also called __
-__ mass observed in __ cells but not __ cells
--Represents a tightly coiled __
--Visible as a small granule attached to the __ of __ cells (esp. buccal smears) and as a “drumstick” appendage to the nucleus of __ |
|
Definition
- barr body
-heterochromatin; female; male
-- X chromosome
-- nuclear envelope; epithelial; neutrophilic leukocytes |
|
|
Term
-nucleolus: Site of __ and initial __
-Non-membranous region that surrounds transcriptionally active __ genes
-Nucleoli vary in __
-More than __ may be present in a cell |
|
Definition
- ribosomal RNA synthesis; ribosome assembly
- rRNA
- size
- 1 |
|
|
Term
| - there are 3 morphologically distinct regions in the nucleolus: __, __, and __ |
|
Definition
| - Fibrillar centers; fibrillar material; granular material |
|
|
Term
-Fibrillar centers: Contain __ loops of chromosomes containing __ genes
-Fibrillar material: __ genes being actively __, Large amounts of __
-Granular material: Densely packed __ particles |
|
Definition
- dna; rRNA
- rRNA; transcribed; rRNA
- preribosomal |
|
|
Term
-__:Separates the nuclear compartment from the cytoplasm
-Formed by 2 membranes with a __ between them
--Cisternal space is continuous with the cisternal space of the __
--Envelope is perforated by __ |
|
Definition
- nuclear envelope
- perinuclear cisternal space
-- rer
-- nuclear pores |
|
|
Term
-Outer nuclear membrane
--Resembles and is continuous with __ membrane
--May have __ on cytoplasmic surface
-Inner nuclear membrane
--Supported by the __
--Contains receptors that bind the __ and __ |
|
Definition
-
-- rer
-- ribosomes
-
-- nuclear lamina
-- lamina; chromosomes |
|
|
Term
- nuclear lamina: Network of __ having a __ function
--Serves as a __ for chromatin, chromatin-associated proteins, nuclear pores, and membranes of the nuclear envelope |
|
Definition
- protein filaments; supporting
- scaffolding |
|
|
Term
- nuclear pores: 70-80 nm openings formed by the merging of the __ and __
-Each pore contains a __ complex consisting of __ that mediate transport in and out of the nucleus
--Large proteins and macromolecular complexes are transported by a __
--Small molecules may cross water-filled channels by __
--Small __ may also be selectively transported |
|
Definition
- inner; outer nuclear membranes
- nuclear pore; proteins
-- GTP dependent mechanism
-- diffusion
-- proteins |
|
|
Term
- __: Material enclosed by the nuclear envelope exclusive of the chromatin and nucleolus
-- includes __, __, and __ |
|
Definition
nucleoplasm
-- nucleoskeleton, nuclear lamina, and rna transcription and processing machinery |
|
|
Term
- __: Self-regulated sequence of events that controls cell growth and cell division
-- two principal phases include __ and __
-- __: partitioning of the genome
-- __: represents growth of the cell |
|
Definition
- cell cycle
-- interphase and M phase (mitosis)
-- m phase (mitosis)
-- interphase |
|
|
Term
- interphase is further divided into 3 phases: __, __, and __
-- checkpoints control progression through the cell cycle |
|
Definition
|
|
Term
- G1
-- gathers __
-- synthesis of __ and __
-- cell __ restored |
|
Definition
-- nutrients
-- RNA; proteins
-- volume |
|
|
Term
-G1 Checkpoints
--__: Most important checkpoint (point of no return)
--Mediated by __ and __
-G1 DNA damage checkpoint
--Tumor suppressing protein __ mediates
--High p53 __ cell cycle
-Cell may leave the cell cycle and enter __ or undergo programmed cell __ |
|
Definition
- restriction point
- retinoblastoma susceptibility protein (pRB); essential transcription factors (E2F)
-- p53
-- arrests
- G0; death |
|
|
Term
-S
-- __ is replicated
-- __ checkpoint |
|
Definition
|
|
Term
G2 cell cycle
-Accumulation of __
-__ synthesis
-Synthesis of chromosomal __
-G2 DNA damage __
-__ DNA checkpoint |
|
Definition
- energy
- tubulin
- nonhistone proteins
- checkpoint
- unreplicated |
|
|
Term
M (mitosis)
- includes __ and __
- __ assembly checkpoint
- __ segregation checkpoint |
|
Definition
- karyokinesis; cytokinesis
- spindle assembly
- chromosome |
|
|
Term
-Failure of cell cycle checkpoints to function properly may lead to __ cell development
-Mitotic catastrophe (abnormal chromosome segregation) may lead to __
-Restriction point failure may lead to __ inhibition |
|
Definition
- tumor
-- aneuploid cells
-- loss of contact |
|
|
Term
-Passage through the cell cycle is driven by __ that are cyclically synthesized and degraded
-Two-protein complexes consisting of a __ and a __ power cells through checkpoints of the cell cycle |
|
Definition
- proteins
- cyclin; cyclin dependent kinase |
|
|
Term
- __:Process of nuclear and cellular division where a parent cell produces two daughter cells with sets of chromosomes identical to that of the parent cell
-- what are the 4 phases of mitosis |
|
Definition
-mitosis
-- prophase, metaphase, anaphase, telephase |
|
|
Term
Prophase
-Chromosomes condense and become visible
--Sister chromatids are held together by __ and the __
-__ migrate to opposite poles
-__ disappears
-__ forms
-A __ forms on each chromatid
-__ disassembles |
|
Definition
- chromosomes
-- cohesions; centromere
- centrosomes
- nucleolus
- mitotic spindle
- kinetochore
- nuclear envelope |
|
|
Term
-Metaphase
--Chromosomes migrate to the __
--__ spindle organizes around the __-organizing centers
--__ attach at the kinetochores
-Anaphase
--__ separate and are pulled toward __ of the cell |
|
Definition
-- equatorial plane
-- mitotic spindle; microtubule
-- microtubules
-
-- sister chromatids; opposite poles |
|
|
Term
Telophase
-__ is reconstituted around the chromosomes at each pole
-__ uncoil
-__ reappears
-Cytokinesis
--Ring of __ and __ filaments around the perimeter of the cell contracts and pinches the cell into 2 daughter cells |
|
Definition
- nuclear envelope
- chromosomes
- nucleolus
- actin; myosin II |
|
|
Term
-__:Two sequential cell divisions that produce gametes containing half the number of chromosomes and half the DNA found in somatic cells
- resulting cells are genetically __
-- segregation of __ and __ chromosomes
-- __ achieves genetic recombination |
|
Definition
- meiosis
- unique
-- paternal; maternal
-- crossing over |
|
|
Term
-Phases of meiosis are similar to the phases of __
-No __ between the successive divisions
-Progression of chromosome number and DNA content
--2n, 4d at start of meiosis after an S phase
--1n, 2d after meiosis I
--1n, 1d after meiosis II |
|
Definition
|
|
Term
meiosis: prophase I
- __ phase of 5 stages
- events include __, __, and __
--__: Chromatin condensation and pairing of homologous chromosomes
--__: Synapsis, formation of the synaptonemal complex
--__: Crossing-over |
|
Definition
- extended
- pairing; synapsis; recombination
-- leptotene
-- zygotene
-- pachytene |
|
|
Term
- Diplotene
-- __ dissolves
-- __ condense further
-- __ appear
- diakinesis
-- __ condensation
-- __ disappears
-- __ disintegrates |
|
Definition
--synaptonemal complex
-- chromosomes
-- chiasmata
-
-- maximum chromosome
-- nucleolus
-- nuclear envelope |
|
|
Term
-Metaphase I
--Paired chromosomes align at __
--__ breakdown
-Anaphase I
--__ does not split, sister chromatids stay together
Members of each homologous pair moves to __
--- also called ___ |
|
Definition
-- equatorial plate
-- chiasmata
-
-- centromeres
-- opposite poles
--- random assortment |
|
|
Term
Telophase I
- __ reforms
- __ divides
- produces daughter cells that are __,__ |
|
Definition
- nuclear envelope
- cytoplasm
- 1n, 2d |
|
|
Term
Meiosis II
-After meiosis I, cells __ enter meiosis II
-Essentially a __
-A 1n, 2d cell becomes two __, __ daughter cells
-Unlike mitosis, the daughter cells are not __ |
|
Definition
- quickly
- mitosis
- 1n, 1d
- genetically identical |
|
|
Term
-__ may result from accidental cell injury or mechanisms that causes cell to self-destruct
-Necrosis
--__ cell death
--__ process
--Unfavorable physical or chemical environment
---Acute cellular injury and damage to the plasma membrane
---Rapid cell __ and __ are characteristic |
|
Definition
- cell death
-
-- accidental
-- pathological
---
--- swelling; lysis |
|
|
Term
-Apoptosis (programmed cell death)
--Physiologic process
--Cells that are no longer needed are __
--Cells initiated an internally encoded program for apoptosis
--A variety of __ or __ signals can initiate apoptosis
--Process is very __ |
|
Definition
-
--
--eliminated
--
-- extrinsic; intrinsic
-- rapid |
|
|
Term
apoptosis:Characteristic morphologic and biochemical features
-DNA fragmentation
--__ event
--__ aggregates, __ may fragment
-Decrease in cell volume
--__ reorganizes
--__ clump, __ forms whorls, __ vesicles fuse with plasma membrane |
|
Definition
-
-- irreversible
-- chromatin; nucleus
-
-- cytoskeleton
-- ribosomes; rer; endocytotic |
|
|
Term
apoptosis
-Loss of mitochondrial function
--Change in membrane permeability
--___ disrupted
--__ is released into the cytoplasm
---Activate __
---___ dismantle the cell
-Membrane blebbing
--___ alterations
--Leads to __ without loss of integrity
---Cell contents remain contained |
|
Definition
--permeability
-- etc
-- cytochrome c
--- caspases
--- caspases
-- plasma membrane
-- blebbing |
|
|
Term
formation of apoptotic bodies
- cell breaks into __
- rapidly removed by __ cells
-- no __ response is elicited |
|
Definition
- membrane bound vesicles
- phagocytic cells
-- inflammatory |
|
|
Term
gemetogenesis: Conversion of germ cells into __ and __
-Primordial germ cells are formed in the __ during the __ and move to the wall of the __
-During the __, they migrate from the __ to the developing __ where they arrive by the end of the __
- __ increase their numbers during migration and in the gonad
- Germ cells undergo __ in preparation for __
--__ to reduce chromosome number
--__ to complete maturation |
|
Definition
male; female gametes
- epiblast;second week; yolk sac
- fourth week; yolk sac; gonads; fifth week
- mitotic divisions
- gametogenesis; fertilization
-- meiosis
-- cytodifferentiation |
|
|
Term
Gametogenesis
- __:Nuclear events, while different in timing, are similar in male and female gamete formation
-__:Cytoplasmic events are quite different
--Females produce __
--Males produce __ |
|
Definition
- meiosis
- cytodifferentiation
-- mature oocytes
-- spermatozoa |
|
|
Term
oogenesis
-Primordial germ cells differentiate into __
-Oogonia undergo __
--By the end of the __, oogonia are arranged in clusters surrounded by a layer of __ derived from the __ |
|
Definition
- oogonia
- mitotic divisions
-- third month; flat epithelium cells; surface epithelium of the ovary |
|
|
Term
oogenesis
-Oogonia continue to divide by __
--Some enter __ and arrest in __ becoming __
--In the __ the number of germ cells in the ovary reaches __
--At this time __ begins, many __ and __ are lost
--By the __, most __ are gone |
|
Definition
- mitosis
-- meiosis; prophase I; primary oocytes
-- fifth month; its maximum (about 7 mil)
- atresia; oogonia; primary oocytes
- seventh month; oogonia |
|
|
Term
oogenesis
-The surviving __ (in __) are now individually surrounded by a layer of __
--These structures are the __
--__ remain arrested in the __ stage of prophase I and do not complete meiosis I until after __ is reached
--Numbers of primary oocytes
---__ to __ at birth
---__ at beginning of puberty
---Fewer than __ will reach ovulation as secondary oocytes |
|
Definition
- primary oocytes; (prophase I); flat epithelial cells
-- primordial follicles
-- primary oocytes; diplotene; puberty
---600,000-800,000
--- 400,000
--- 500 |
|
|
Term
oogenesis
- follicular growth and maturation
-- at puberty a pool of __ is established
---Each month __ begin to grow
---The epithelial cells change from __ to __ and begin to proliferate producing a __ (__)
---The growing follicles are now called __ |
|
Definition
-
-- growing follicles
---15-20 primordial follicles
--- flat; cuboidal; stratified epithelium (granulosa cells)
--- primary follicles |
|
|
Term
oogenesis
-Primary follicles
--The cells of the __ surrounding the growing follicle organize into the __
--The __ cells and the __ secrete a glycoprotein layer around the oocyte called the __
---__ from the granulosa cells and oocyte extend across the __ to transport materials to the __ |
|
Definition
-- ovarian stroma; theca folliculli
-- granulosa; oocyte; zona pellucida
--- cytoplasmic projections; zona pellucida; oocyte |
|
|
Term
oogenesis
Secondary follicle
-As the follicle grows fluid filled spaces develop between the __
--These spaces coalesce into a singe space called the __
-The oocyte is found on the edge of __ surrounded by __, the __ |
|
Definition
- granulosa cells
-- antrum
- antrum; granulosa cells (granulosa cells = follicular cells); cumulus oophorus |
|
|
Term
oogenesis
- mature follicle
-- only __ reaches maturity each ovarian cycle
---The other maturing follicles undergo __
--Mature follicles are often __ or more in diameter |
|
Definition
-
-- one follicle
--- atresia
-- 25mm |
|
|
Term
oogenesis
-A surge of __ induces the __ of the __ to complete __
--The __ is unequally divided between the daughter cells producing one __ with most of the cytoplasm and the first __ with little cytoplasm
--The polar body lies between the __ and the __ in the __
-After meiosis I, the __ enters meiosis II but arrests during __ about __ prior to ovulation
--Meiosis II will complete only if the __ is __
--Without __ the oocyte degenerates about 24 hours after ovulation |
|
Definition
- luteinizing hormone (LH); oocyte; mature follicle; meiosis I
-- cytoplasm; secondary oocyte; polar body
-- secondary oocyte; zona pellucida; perivitelline space
- secondary oocyte; metaphase; 3 hours
-- oocyte; fertilized
-- fertilization |
|
|
Term
spermatogenesis
-At birth, primordial germ cells and supporting cells are present in the __ of the __
--Supporting cells, derived from the __ of the __, will develop into __, or __
-Shortly before puberty
--The sex cords acquire a __ and become the __
--Primordial stem cells give rise to __ |
|
Definition
- sex cords; testis
-- surface epithelium; testis; sustentacular cells; sertoli cells
-
-- lumen; seminiferous tubules
-- spermatogonial stem cells |
|
|
Term
spermatogenesis
-At regular intervals, cells emerge from the spermatogonial cell population to form __
--This marks the beginning of __
-__ undergo a limited number of mitotic divisions
--The last division produces __
-__ then divide to form __ |
|
Definition
- type A spermatogonia
-- spermatogenesis
- type A spermatogonia
-- type B spermatogonia
- type B spermatogonia; primary spermatocytes |
|
|
Term
spermatogenesis
-Primary spermatocytes enter a __ followed by rapid completion of __ producing __
-__ then undergo meiosis II producing __ |
|
Definition
- prolonged prophase (22 days); meiosis I; secondary spermatocytes
- secondary spermatocytes; spermatids |
|
|
Term
spermatogenesis:Spermiogenesis
-Transformation of __ into __
--Formation of the __
--Condensation of the __
--Formation of the __ and __
--Shedding of __ |
|
Definition
- spermatids; spermatozoa
-- acrosome
-- nucleus
-- tail; related structures
-- cytoplasm |
|
|
Term
spermatogenesis
-__ and __ remain embedded in recesses of __ throughout their development
--__ support and protect the germ cells
-Spermatogenesis is regulated by __ production
--All progeny of a single __ remain connected by cytoplasmic bridges |
|
Definition
- spermatogonia; spermatids; sertoli cells
-- sertoli cells
- luteinizing hormone
- type A spermatogonium |
|
|
Term
-Half of all spontaneous abortions have a major __, which include:
--45, X
--Triploidy
--Trisomy 16
-Chromosomal abnormalities account for __ of major birth defects |
|
Definition
- chromosomal defect
-- 45, X
-- Triploidy
-- Trisomy 16
- 7% |
|
|
Term
- __: extra or missing chromosome
-- arise from __ during cell division
---__ gives rise to abnormal gametes
---__ gives rise to mosaicism |
|
Definition
- numerical
-- nondisjunction of chromosomes
--- meiosis
--- mitosis |
|
|
Term
-Clinical syndromes
--Down syndrome: __
--Trisomy 18
--Trisomy 13
--__
---Usually nondisjunction of the XX homologues
--___
---80% due to nondisjunction in the male gamete
Triple X syndrome |
|
Definition
-- trisomy 21
-- klinefelter syndrome: XXY
-- Turner syndrome: 45, X |
|
|
Term
-Translocations: pieces of one chromosome attach to another
--__: no critical material lost
---Normal phenotype
--__: part of chromosome is lost
---Abnormal phenotype
--Gene level problems without loss of material can also arise from translocations |
|
Definition
- translocations
-- balanced
-- unbalanced |
|
|
Term
-__: loss of part of a chromosome
--__ syndrome: partial deletion of 5p
-__: span only a few contiguous genes
--__: deletion of 15q11-15q13
-Fragile sites
--Fragile X syndrome: Xq27 |
|
Definition
- deletions
-- cri-du-chat syndrome
- microdeletions
-- angelman syndrome/prader-willi syndrome |
|
|
Term
down syndrome: trisomy 21
-95% caused by __
--75% in __
---Increasing risk with __
1:2000 if <25
1:300 at age 30
1:100 at age 40
-4% __
--Chromosome 13,14, or 15
-1% __ due to mitotic nondisjunction |
|
Definition
- meiotic nondisjunction
-- oocyte
--- maternal age
- unbalanced translocation
- mosaicism |
|
|
Term
Ovulation
-As the __ undergoes the final steps of maturation, a bulge appears on the surface of the ovary
--An __ appears at the apex called the __
-- high __ results in increased collagenase activity digesting the __ around the follicle |
|
Definition
- follicle
-- avascular spot; stigma
-- LH concentration; fibers |
|
|
Term
-The oocyte and granulosa cells of the __ break free from the __ and are extruded from the ovary
--The granulosa cells arrange into the __
-Corpus luteum
--The __ cells remaining in the ruptured follicle wall and the __ cells change into __ cells
--The area is vascularized forming the __
--Secretes __ which acts on the __ in preparation for implantation |
|
Definition
- cumulus oophorus; follicle wall
-- corona radiata
-
-- granulosa; theca interna; lutean
-- corpus luteum
-- progesterone; uterine mucosa |
|
|
Term
oocyte transport
-At ovulation the fimbriae of the __ move over the surface of the __
-Sweeping motions of the __ and __ movement of the tube lining carry the __ into the tube
--The __ cells withdraw their processes from the __
--A fertilized oocyte takes __ to reach the uterine cavity |
|
Definition
- uterine tube; ovary
- fimbriae; ciliary; oocyte
-- granulosa; zona pellucida
-- 3-4 days |
|
|
Term
fertilization
-Fertilization normally occurs in the __ of the __
-Spermatozoa reach the __ primarily by their own __
--Spermatozoa may survive in the female reproductive tract for __
--1% of spermatozoa deposited in the vagina enter the __
--It takes 2-7 hours to migrate from the __ to the __
--Upon reaching the __ of the tube the spermatozoa become less __ and stop their __ |
|
Definition
- ampulla; uterine tube
- ampulla; propulsion
-- several days
-- cervix
-- cervix; uterine tube
-- isthmus of the tube; motile; migration |
|
|
Term
fertilization
-At ovulation, the __ become motile again and swim to the __
-Spermatozoa must undergo __ before becoming capable of fertilization
--__ in the female reproductive tract
--Mostly occurs in the __
--Lasts about __
--A __ coat and __ are removed from the plasma membrane overlying the __ |
|
Definition
- spermatozoa; ampulla
- capacitation
-- conditioning
-- uterine tube
-- 7 hrs
-- glycoprotein; seminal plasma proteins; acrosome |
|
|
Term
three phases of fertilization
1.
2.
3. |
|
Definition
1. penetration of the corona radiata
2. penetration of the zona pellucida
3. fusion of the oocyte and spermatozoon membranes |
|
|
Term
phase 1: penetration of the corona radiata
--Only __ reach the site of fertilization
--Only one will fertilize the __
--__ easily penetrate the __ |
|
Definition
-
-- 300-500 spermatozoa
-- oocyte
-- capacitated spermatozoa; corona radiata |
|
|
Term
Phase 2: Penetration of the Zona Pellucida
-__ bind to __ of the zona pellucida
-The acrosomal reaction culminates with the release of ___ to penetrate the __ of the zona pellucida
-When the spermatozoon contacts the __, the oocyte releases enzymes from __ that alter the __ and __ to prevent further penetration of the oocyte or binding to the zona pellucida |
|
Definition
- spermatozoa; ligand proteins
- acrosomal enzymes; glycoprotein shell
- oocyte plasma membrane; cortical graules; plasma membrane; zona pellucida |
|
|
Term
-Phase 3: Fusion of the __ and __ membranes
--After adhesion to the surface of __ by the __, the membranes of each fuse
--The __ and __ of the spermatozoon enters the __ of the oocyte |
|
Definition
-Phase 3: Fusion of the oocyte and spermatozoon membranes
--After adhesion to the surface of oocyte by the spermatozoon, the membranes of each fuse
--The head and tail of the spermatozoon enters the cytoplasm of the oocyte |
|
|
Term
-The entry of the spermatozoon triggers:
--__ and __ reactions
--Resumption of the __
---Produces the definitive __ and the __
---The chromosomes arrange into the female ___
--Metabolic activation of the oocyte
---Initial cellular and molecular events of __ |
|
Definition
-The entry of the spermatozoon triggers
--Cortical and zonal reactions
--Resumption of the second meiotic division
---Produces the definitive oocyte and the second polar body
---The chromosomes arrange into the female pronucleus
--Metabolic activation of the oocyte
---Initial cellular and molecular events of embryogenesis
-- oocyte
--- embryogenesis |
|
|
Term
fertilization
-The __ moves close to the female __
--Its nucleus swells forming the __
--The __ detaches and degenerates
-Each __ replicates its DNA
-After DNA replication the chromosomes of both __ organize on a spindle in preparation for a __
--Each of the two resulting cells of the zygote have a __ chromosome number and DNA content |
|
Definition
-The spermatozoon moves close to the female pronucleus
--Its nucleus swells forming the male pronucleus
--The tail detaches and degenerates
-Each pronucleus replicates its DNA
-After DNA replication the chromosomes of both pronuclei organize on a spindle in preparation for a mitotic division
--Each of the two resulting cells of the zygote have a diploid chromosome number and DNA content |
|
|
Term
The main results of fertilization:
-Restoration of the __ number of chromosomes
--Half from the mother; half from the father
-Determination of __
--__ carrying spermatozoon produces female embryo
--__ carrying spermatozoon produces male embryo
-Initiation of __ |
|
Definition
The main results of fertilization
-Restoration of the diploid number of chromosomes
--Half from the mother; half from the father
-Determination of sex
--X carrying spermatozoon produces female embryo
--Y carrying spermatozoon produces male embryo
-Initiation of cleavage (cell division) |
|
|
Term
Cleavage
-After reaching the two-cell stage, the zygote undergoes a series of __
--Cells become __ with each cleavage division
--Cells are called __
--Loose cluster of cells through the __ |
|
Definition
- mitotic divisions
-- smaller
-- blastomeres
-- 8-cell stage |
|
|
Term
cleavage
-At the 8-cell stage the cells undergo __
--Blastomeres maximize contact with each other forming __
--Separates inner cells, which communicate extensively by __, from outer cells
-About 3 days after fertilization, the compacted cells divide again forming the __
--Inner cells form the __
---Gives rise to the tissues of the __
--Surrounding cells form the __
---Forms the __ |
|
Definition
- compaction
-- tight junctions
-- gap junctions
- 16 cell morulla
-- inner cell mass
--- embryo proper
-- outer cell mass
--- trophoblast |
|
|
Term
-About the time the __ enters the uterine cavity, fluid begins to penetrate the __ and enter the intercellular spaces of the inner cell mass
--The spaces become confluent forming a single cavity, the __ |
|
Definition
- morula; zona pellucida
-- blastocele |
|
|
Term
-With formation of the blastocele, the embryo is now called a __
--Inner cell mass now called the __ is at one pole
--Outer cell mass, or __, forms the wall of the __
--The __ has disappeared
---Allows __ to begin |
|
Definition
- blastocyst
-- embryoblast
-- trophoblast; blastocyst
-- zona pellucida
--- implantation |
|
|
Term
implantation
-__ cells over the embryoblast pole begin to penetrate the uterine epithelial lining cells on about the __
--The embryo is captured on the mucosa by __ on the trophoblastic cells
--__ expressed by the trophoblast interact with laminin and fibronectin extracellular matrix molecules promoting __ and __ |
|
Definition
- trophoblastic; 6th day
-- selectins
-- integrins; attachment; invasion |
|
|
Term
Recall:
-The inner cells of the __ form the inner cell mass. The inner cell mass undergoes a name change and becomes the __.
-The outer cell mass forms the __, which contributes to __.
-Note: Sometimes the terms embryo and __ are used interchangeably. |
|
Definition
- morula; embryoblast
- trophoblast; placenta formation
- blastocyst |
|
|
Term
-The second week is often referred to as the “__.”
-The trophoblast differentiates into the __ and the __.
-The embryoblast differentiates into the __ and the __.
-The extraembryonic mesoderm splits into two layers: the __ and __.
-Two cavities form: the __ cavity and the __ cavity.
-Note: Embryos of the same fertilization age do not necessarily __ at the same rate. |
|
Definition
- week of twos
- cytotrophoblast; synctiotrophoblast
- epiblast; hypoblast
- splanchnopleure; somatopleure
- amniotic; yolk sac
- develop |
|
|
Term
DAY 8
-The __ becomes partially embedded in the __.
-There are two layers of the trophoblast:
1.__ – has an __ cellular layer composed of mononuclear cells (cells containing only one nucleus).
2. __ – the __ cellular layer with multinucleate cells (cells with multiple nuclei); there are no distinct cellular boundaries |
|
Definition
- trophoblast; endometrium
-
1. cytotrophoblast; inner
2. syncytiotrophoblast; outer |
|
|
Term
DAY 8
- __ occurs in the cytotrophoblast, which acts as a __.
-Cells from the cytotrophoblast migrate into the __ and fuse together, forming the __ seen in the syncytiotrophoblast.
-The embryoblast/inner cell mass differentiates into two layers:
1.__ – a layer of __ cells near the blastocyst cavity.
2.__ – a layer of __ cells near the amniotic cavity.
-Both of these germ layers form a flat disc known as the __. |
|
Definition
- mitosis; cellular reservoir
- syncytiotrophoblast; multinucleate
1. hypoblast; cuboidal
2. epiblast; high columnar
- bilaminar germ disc |
|
|
Term
Day 8
-The __ begins as a small cavity in the epiblast.
-__ are epiblast cells that are adjacent to the cytotrophoblast.
-__ line the amniotic cavity.
-The __ adjacent to the implantation site is edematous and highly __.
-The large, tortuous glands secrete lots of __ and __. |
|
Definition
- amniotic cavity
- amnioblasts
- amnioblasts
- endometrium; vascular
- glycogen; mucus |
|
|
Term
DAY 9
-The blastocyst is more deeply embedded in the __.
-The penetration defect in the surface epithelium of the endometrium is closed by a structure called the __
-The __ begins to differentiate near the embryonic pole, where vacuoles or spaces appear in the syncytium.
-When these vacuoles fuse, they form larger spaces called __.
-This phase of trophoblast development is called the __. |
|
Definition
- endometrium
- fibrin coagulum
- trophoblast
- lacunae
- lacunar stage |
|
|
Term
DAY 9
-At the __ (the pole opposite the embryonic pole), flattened cells that originate from the hypoblast form a thin membrane called the __ membrane that lines the inner surface of the __.
-This membrane, together with the hypoblast, forms the lining of the __, or the __. |
|
Definition
- abembryonic pole; exocoelomic membrane; cytotrophoblast
- exocoelomic cavity; primitive yolk sac |
|
|
Term
DAYS 11 and 12
-By this time, the __ is almost completely embedded in the endometrium.
-The defect in the __ is almost completely covered.
-The blastocyst causes a slight protrusion into the __.
-The trophoblast is characterized by __ spaces in the syncytium that form an intercommunicating network.
-This network is particularly evident at the __.
-At the abembryonic pole, the trophoblast still consists mainly of __. |
|
Definition
- blastocyst
- endometrium
- uterine lumen
- lacunar spaces
- embryonic pole
- cytotrophoblastic cells |
|
|
Term
DAYS 11 and 12
-Cells of the __ penetrate deeper into the endometrium and erode the lining of the maternal capillaries.
-The __ are congested and dilated; they are called __.
-The __ become continuous with the sinusoids, and maternal blood enters the lacunar system.
-As the __ continues to erode more and more sinusoids, maternal blood begins to flow through the __ system.
-The __* is then established. |
|
Definition
-syncytiotrophoblast
- capillaries; sinusoids
- lacunae
- trophoblast; trophoblastic
- Uteroplacental circulation |
|
|
Term
days 11 and 12
-Meanwhile…cells derived from the yolk sac form a loose connective tissue between the inner surface of the cytotrophoblast and the outer surface of the exocoelomic cavity called the __.
-The __(previous) eventually fills all of the space between the __ externally and the __ internally.
-Large cavities develop in the extraembryonic mesoderm, and when these cavities join together, they form a new space known as the __, or the __
-This space surrounds the primitive __ and __ except where the bilaminar disc is connected to the trophoblast by the connecting stalk. |
|
Definition
-extraembryonic mesoderm
- extraembryonic mesoderm; trophoblast; exocoelomic membrane
- extraembryonic coelom; chorionic cavity
- yolk sac; amniotic cavity |
|
|
Term
DAYS 11 and 12
-The extraembryonic mesoderm lining the cytotrophoblast and amnion is called the __.
-The lining covering the yolk sac is known as the __.
-Growth of the __ is slow compared to that of the trophoblast, so the disc remains small.
-Around the site of implantation, cells of the endometrium become polyhedral in shape, become filled with __ and __.
-__ fills the extracellular spaces.
-These changes, known as the __, occur in the area immediately surrounding the implantation site but soon occur throughout the endometrium. |
|
Definition
-The extraembryonic mesoderm lining the cytotrophoblast and amnion is called the extraembryonic somatopleuric (parietal) mesoderm.
-The lining covering the yolk sac is known as the extraembryonic splanchnopleuric (visceral) mesoderm.
-Growth of the bilaminar disc is slow compared to that of the trophoblast, so the disc remains small.
-Around the site of implantation, cells of the endometrium become polyhedral in shape, become filled with glycogen and lipids.
-Fluid fills the extracellular spaces.
-These changes, known as the decidua reaction, occur in the area immediately surrounding the implantation site but soon occur throughout the endometrium. |
|
|
Term
day 13
-The defect in the __ usually has healed by this time.
-However, some bleeding may occur at the implantation site due to increased blood flow into the __.
-Since this happens around day __ of the menstrual cycle, it is often confused with normal menstrual bleeding.
-This may cause __ in determining the expected __ |
|
Definition
- endometrium
- lacunar spaces
- 28; normal
- inaccuracy; date of delivery |
|
|
Term
DAY 13
-__ form in the trophoblast.
-Cells of the __ proliferate and penetrate into the __.
-Cellular columns surrounded by syncytium form structures called __*. |
|
Definition
- villous structures
- cytotrophoblast; syncytiotrophoblast
- primary villi |
|
|
Term
day 13
-The __ produces additional cells that migrate along the inside of the exocoelomic membrane.
-These cells proliferate and gradually form a new cavity within the __.
-This new cavity is known as the __ or
__.
-This new yolk sac is much __ than the __, or __.
-During its formation, large portions of the __ are pinched off.
-These pinched off portions are called __, which are often found in the extraembryonic coelom or chorionic cavity |
|
Definition
-The hypoblast produces additional cells that migrate along the inside of the exocoelomic membrane.
-These cells proliferate and gradually form a new cavity within the exocoelomic cavity.
-This new cavity is known as the secondary yolk sac or definitive yolk sac.
-This new yolk sac is much smaller than the original exocoelomic cavity, or primitive yolk sac.
-During its formation, large portions of the exocoelomic cavity are pinched off.
-These pinched off portions are called exocoelomic cysts, which are often found in the extraembryonic coelom or chorionic cavity |
|
|
Term
day 13
-The extraembryonic coelom expands and forms a large cavity, the __.
-The extraembryonic mesoderm lining the inside of the cytotrophoblast is called the __.
-The only place where extraembryonic mesoderm crosses the chorionic cavity is in the __.
-When the blood vessels develop, the connecting stalk becomes the __ |
|
Definition
- chorionic cavity
- chorionic plate
- connecting stalk*
- umbilical cord |
|
|
Term
is the conceptus an invader?
-Because 50% of the implanting embryo’s genome is derived from the father, it is a foreign body that should be rejected by the mother.
-Recent evidence suggests that a combination of factors protects the conceptus, including production of __ and proteins, as well as the expression of an unusual __ class __ molecule (HLA-G) that blocks the recognition of the conceptus as foreign tissue.
-If the mother suffers from an __, such as systemic lupus erythematosus, antibodies generated by the disease may attack the conceptus and reject it.
-Patients with __ have poor reproductive outcomes and histories of spontaneous abortions |
|
Definition
-
- immunosuppressive cytokines; MHC; IB molecule
- autoimmune disease
- autoimmune disease |
|
|
Term
Abnormal implantation
-Abnormal implantation sites occur even within the uterus.
-Normally, the __ implants along the anterior or posterior uterine wall.
-Occasionally, the blastocyst implants close to the __ (opening) of the cervix, so that later in development, the placenta crosses the opening.
-This condition, which is called __, causes severe, even life-threatening bleeding in the second part of pregnancy and during delivery. |
|
Definition
-
- blastocyst
- internal os
- placenta previa |
|
|
Term
-Implantation can take place outside the uterus, resulting in an __ or __.
-Ectopic pregnancies can occur at any place in the abdominal cavity, ovary, or uterine tube.
-However, 95% of ectopic pregnancies occur in the __, mostly in the __. |
|
Definition
- extrauterine; ectopic pregnancy
-
- uterine tube***; ampulla*** |
|
|
Term
-In the __, the blastocyst most frequently attaches itself to the peritoneal lining of the __ or the __.
-Sometimes, the blastocyst develops within the ovary causing a __
-In most ectopic pregnancies, the embryo dies around the __ of gestation, causing severe bleeding and abdominal pain in the mother. |
|
Definition
- abdominal cavity; rectouterine cavity; pouch of douglas
- primary ovarian pregnancy
- second month |
|
|
Term
abnormal blastocysts
-It is likely that most __ would not produce any signs of pregnancy.
-This is because the trophoblast was so inferior that the __ could not have persisted.
-These embryos probably would have been aborted with the next __, so pregnancy would not have been detected |
|
Definition
- abnormal blastocysts
- corpus luteum
- menstrual cycle |
|
|
Term
-In some cases, some abnormal blastocysts will have trophoblastic development and formation of placental tissues.
-This condition is called a __.
-Moles secrete high levels of __ and may produce benign or malignant __ (invasive mole, choriocarcinoma). |
|
Definition
-
- hydatidiform mole
- hCG; tumors |
|
|
Term
-Genetic analysis of hydatidiform moles reveals that although male and female pronuclei may be genetically equivalent, they may be different functionally.
-This evidence comes from the fact that while cells of the moles are diploid, their entire genome is __.
-So, most moles arise from the fertilization of an oocyte lacking a nucleus, followed by duplication of the male chromosomes to restore the diploid number.
-These results also suggest that __ regulate most of the development of the __, since in moles this tissue differentiates even in the absence of a female pronucleus. |
|
Definition
-
- paternal
-
- paternal genes; trophoblast |
|
|
Term
-__ is the process that establishes all three germ layers: __, __, and __
-Gastrulation begins with the formation of the __ on the surface of the __.
-The cephalic end of the streak, the __, consists of a slightly elevated area surrounding the __.
-Cells of the __ migrate toward the primitive streak.
-When they arrive, these cells become __, detach from the epiblast, and slip beneath it.
-The inward movement of the cells is called __. |
|
Definition
-Gastrulation is the process that establishes all three germ layers: ectoderm, mesoderm, and endoderm.
-Gastrulation begins with the formation of the primitive streak on the surface of the epiblast.
-The cephalic end of the streak, the primitive node, consists of a slightly elevated area surrounding the small primitive pit.
-Cells of the epiblast migrate toward the primitive streak.
-When they arrive, these cells become flask-shaped, detach from the epiblast, and slip beneath it.
-The inward movement of the cells is called invagination. |
|
|
Term
gastrulation
-Cell migration and specification are controlled by __, which is synthesized by __.
-__(previous) down regulates __, a protein that normally binds __ cells together.
-FGF8 then controls cell specification into mesoderm by regulating __ |
|
Definition
- fibroblast growth factor 8 (FGF8); streak cells
- fgf8; E-cadherin; epiblast
- mesoderm; brachyury (T) expression |
|
|
Term
gastrulation
-Once the cells have invaginated, some of these cells displace the hypoblast, creating the __, and others come to lie between the epiblast and newly created endoderm to form __.
-Cells remaining in the epiblast then form __.
-So, the epiblast is the source of all of the germ layers.
-Cells in the germ layers will give rise to all of the tissues and organs in the embryo. |
|
Definition
- embryonic endoderm; mesoderm
- ectoderm
- epiblast
- germ layers |
|
|
Term
gastrulation
-As more cells move between the __ and __ layers, they begin to spread laterally and cranially.
-Gradually they migrate beyond the margin of the disc and establish contact with the __ that covers the __ and __.
-In the cephalic direction, they pass on each side of the __ |
|
Definition
- epiblast; hypoblast
- extraembryonic mesoderm; yolk sac; amnion
- prechordal plate |
|
|
Term
gastrulation
-The __ itself forms between the tip of the __ and the __ membrane and is derived from some of the first cells that migrate through the node in the cephalic direction.
-Later, the __(previous) will be important for the induction of the __.
-The __ at the cranial end of the disc consists of a small region of tightly adherent __ and __ cells that represents the future opening of the __.
-Note: The new terminology is __ membrane, replacing buccopharyngeal membrane. |
|
Definition
- prechordal plate; notochord; buccopharyngeal membrane
- prechordal plate; forebrain
- buccopharyngeal membrane; ectoderm; endoderm; oral cavity
- oropharyngeal |
|
|
Term
formation of the notochord
-__ invaginating in the primitive pit move forward cranially until they reach the __.
-Prenotochordal cells become inserted into the __, so that for a short time, the midline of the embryo consists of two cell layers that form the __
-As the hypoblast is replaced by __ cells that move in at the streak, cells of the notochordal plate proliferate and detach from the endoderm.
-They then form a solid cord of cells, the definitive __.
-The notochord underlies the __ and serves as the basis for the __. |
|
Definition
- prenotochordal cells; prechordal plate
- hypoblast; notochordal plate
- endoderm
- notochord
- neural tube; axial skeleton |
|
|
Term
-The _ end of the __ forms first, while the __ regions are added as the primitive streak assumes a more caudal position.
-The notochord and prenotochordal cells extend cranially to the __, an area just caudal to the __ and caudal to the __.
-At the point where the pit forms an indentation in the epiblast, the __ temporarily connects the __ and __ cavities. |
|
Definition
- cranial end; notochord; caudal
- prechordal plate; buccopharyngeal membrane; primitive pit
- neurenteric canal; amniotic; yolk sac |
|
|
Term
formation of the notochord
-The __ is formed at the caudal end of the embryonic disc.
-The __(previous_), which is similar to the buccopharyngeal membrane, consists of tightly adherent __ and __ cells.
-When the cloacal membrane appears, the posterior wall of the __ forms a small diverticulum that extends into the __.
-The diverticulum is called the __ or __.
-The __ remains rudimentary in humans and can be involved in abnormalities of bladder development. |
|
Definition
- cloacal membrane
- cloacal membrane; ectoderm; endoderm
- yolk sac; connecting stalk
- allantoenteric diverticulum; allantois
- allantois |
|
|
Term
-Establishment of body axes, anteroposterior, dorsoventral, and left-right, takes place before and during __.
-The anteroposterior axis is signaled by cells at the anterior (cranial) margin of the __.
-This area, the __ expresses genes essential for head formation, including three transcription factors and the secreted factors __ and __.
-These genes and growth factors establish the __ of the embryo before gastrulation.
-__, a growth factor, initiates the formation of and maintains the __.
-Once the streak is formed, a number of __ regulate formation of dorsal and ventral mesoderm and head and tail structures |
|
Definition
- gastrulation
- embryonic disc
- anterior visceral endoderm (AVE); cerberus; lefty
- cranial end
- nodal; primitive streak
- genes |
|
|
Term
establishment of body axis
-__ is secreted throughout the embryonic disc.
-__ and __ cause mesoderm to be ventralized, which contributes to the formation of __, __, and body wall __.
-All mesoderm would be ventralized if BMP4 were not blocked by other genes expressed by the node.
-So, the node is considered to be the organizer.
-Hans Spemann first designated the node as the organizer. |
|
Definition
-bone morphogenetic protein 4 (BMP4)
- BMP4; FGF; kidneys; blood; mesoderm
- BMP4
- node; organizer |
|
|
Term
establishment of body axes
-So, __ (activated by the transcription factor __), __ and __ antagonize the activity of __.
-As a result, __ is dorsalized into __, __, and __.
-Later, these three genes are expressed in the __, and are important in __ in the cranial region. |
|
Definition
- chordin; (goosecoid); noggin; follistatin; BMP4
- cranial mesoderm; notochord; somites; somitomeres
- notochord; neural induction |
|
|
Term
establishment of body axes
-___ maintains the node and later induces regional specificity in the forebrain and midbrain areas.
-Without __, embryos fail to gastrulate properly and lack forebrain and midbrain structures |
|
Definition
|
|
Term
establishment of body axes
-Note: __ activates inhibitors of BMP4 and contributes to the regulation of __.
-Over- or under expression of this gene results in __ of the head region.
-__ and some types of conjoined twins can result due to over expression of __. |
|
Definition
- goosecoid; head development
- severe malformations
- head duplications; goosecoid |
|
|
Term
establishment of body axes
-Regulation of __ formation in the middle and caudal regions of the embryo is controlled by the __ gene expressed in the __, __ cells, and __.
-__ encodes a transcription factor which causes mesoderm formation in the middle and caudal regions.
-The absence of Brachyury results in shortening of the __ (__).
-The degree of shortening depends on the time at which the protein becomes deficient. |
|
Definition
- dorsal mesoderm; brachyury; node; notochord precursor; notochord
- brachyury
- embyronic axis (caudal dysgenesis) |
|
|
Term
-Gastrulation may be interrupted by __ or __.
-In caudal __ or __, insufficient mesoderm is formed in the caudalmost region of the embryo.
-Because this mesoderm contributes to the formation of the lower limbs, urogenital system (intermediate mesoderm), and lumbosacral vertebrae, abnormalities in these structures are seen. |
|
Definition
- genetic abnormalities; toxic insults
- caudal dysgenesis; sirenomelia |
|
|
Term
-_:Affected individuals exhibit a variety of defects, including hypoplasia and fusion of the lower limbs, vertebral abnormalities, renal agenesis, imperforate anus, and anomalies of the genital organs.
-The condition is associated with __, __, and the absence of __.
-Sirenomelia is almost always __, with __ of babies stillborn and approximately __ dying within a few minutes to a few days. |
|
Definition
- caudal dysgenesis (sirenomelia)
- maternal diabetes; twinning; brachyury
- fatal; 50%; 50% |
|
|
Term
establishment of body axes
-__ is established early in development and is orchestrated by a cascade of genes.
-When the primitive streak appears, __ is secreted by cells in the __ and __, which induces expression of __, but only on the __ side of the embryo.
-Later, after the establishment of the neural plate, __ maintains __ expression in the lateral plate mesoderm as well as __.
-Both __ and __ upregulate PITX2.
-PITX2 is a homeobox-containing transcription factor responsible for establishing __.
-If the gene is expressed on the right side, laterality defects such as __ and __ result |
|
Definition
- left-right sidedness
- FGF8; node; primitive streak; nodel; left
- FGF8; nodal; lefty-2
- nodal; lefty-2
- left sidedness
- situs inversus; dextrocardia |
|
|
Term
establishment of body axes
-Lefty-1 is expressed on the __ of the __ of the __ and may act as a barrier to prevent left-sided signals from crossing over.
-__ may also act as a repressor for left-sided gene expression on the right side.
-The __ gene, that encodes a transcription factor secreted by the notochord, is also essential for the expression of __, __ and __. |
|
Definition
- left side; floor plate; neural tube
- SHH (sonic hedge hog)
- brachyury T; nodal; lefty-1; lefty-2 |
|
|
Term
establishment of body axes
-The neurotransmitter __ plays a crucial role in the signaling cascade that establishes laterality.
-5HT is concentrated on the left side, probably because it is broken down by the enzyme __ on the right and upstream from FGF8 signaling.
-Alterations in 5HT signaling result in __, __, and other __. |
|
Definition
- serotonin (5ht)
- monoamine oxidase
- situs inversus; dextrocardia; heart defects |
|
|
Term
establishment of body axes
-Genes regulating right-sided development are not as well defined as those on the left, although expression of the transcription factor ___ is restricted to the right lateral plate mesoderm and probably regulates the effector genes responsible for establishing the right side.
-It is still not understood why the cascade is initiated on the left, but __ on cells in the __ beat to create a gradient established by __ and small __ transport. |
|
Definition
- Snail
- cilia; node; gap junctions; ion |
|
|
Term
establishment of fate map
-Cells of the epiblast that enter through the cranial region of the node become __.
-Cells migrating at the lateral edges of the node and from the cranial end of the streak become __.
-Cells migrating through the midstreak region become __.
-Those cells migrating through the more caudal part of the streak from __
-Cells migrating through the caudalmost part of the streak contribute to __ (the other source of this type of mesoderm is the primitive yolk sac (hypoblast). |
|
Definition
- notochord
- paraxial mesoderm
- intermediate mesoderm
- lateral plate mesoderm
- extraembryonic mesodrm |
|
|
Term
growth of the embryonic disc
-The __ is initially flat and almost round, but gradually becomes elongated, with a broad __ end and a narrow __ end.
-Expansion of the disc occurs mainly in the __ region, while the region of the __ remains about the same size.
-Growth and elongation of the cephalic part of the disc are caused by a continuous migration of cells from the __ region in a cephalic direction.
-Invagination of surface cells in the __ and their subsequent migration forward and laterally continues until the end of the __.
-At that time, the primitive streak shows signs of __, __, and soon __ |
|
Definition
- embryonic disc; cephalic; caudal
- cephalic; primitive streak
- primitive streak
- primitive streak; fourth week
- regression;rapidly shrinks; disappears |
|
|
Term
growth of the embryonic disc
-It is interesting that the __ at the __ end of the embryo continues to supply new cells until the end of the __.
-In the cephalic part of the embryo, the germ layers begin their differentiation by the middle of the __, whereas in the caudal part, differentiation begins by the end of the __.
-So, gastrulation continues in __ segments, while __ structures are differentiating, causing the embryo to develop __ |
|
Definition
-primitive streak; caudal; fourth week
- third week; fourth week
- caudal; cranial; cephalocaudally |
|
|
Term
further development of the trophoblast
-By the start of the third week, the trophoblast has __: cytotrophoblast core covered by a __.
-During further development, __ cells invade the core of the primary villi and grow toward the __.
-This newly formed structure is known as a __. |
|
Definition
- primary villi; synctial layer
- mesodermal; decidua
- secondary villus |
|
|
Term
further development of the trophoblast
-By the end of the third week, __ in the core begin to differentiate into __ and __, forming the __ system.
-The villus is now called a __ or definitive villus.
-Capillaries in __(previous) make contact with __ developing in __ of the chorionic plate and the connecting stalk.
-These vessels, in turn, establish contact with the __, connecting the placenta and the embryo.
-So, when the heart begins to beat in the __, the __ system is ready to supply the embryo with nutrients and oxygen. |
|
Definition
- mesodermal cells; blood vessels; blood cells; villous capillary
- tertiary villus
- tertiary villi; capillaries; mesoderm
- intraembryonic circulatory system
- fourth week; villus |
|
|
Term
clinical correlate
-The beginning of the third week of development is a highly sensitive stage for __.
-__ are drugs or other agents that cause abnormal prenatal development.
-At this time, __ can be made for various organ systems, such as those for the eyes and brain.
-These cell populations may be damaged by __.
-For example, high doses of __ at this stage kill cells in the __ of the germ disc, producing a deficiency of the midline in __ structures.
-This results in a condition known as __.
-In severe cases, the __ are fused and the __ is located above the eye.
-In mild cases, the only indication is a single __. |
|
Definition
- teratogenic insulte
- teratogens
- fate maps
- teratogens
- alcohol; anterior midline; craniofacial
- holoprosencephaly
- eyes; nose
- incisor tooth |
|
|
Term
clinical correlate
-__ is a condition in which the viscera (organs) of the thorax and abdomen are transposed or reversed.
It has been estimated that situs inversus occurs once in __ to __ births.
-Despite this reversal, other structural abnormalities occur only slightly more __.
-Approximately 20% of patients with complete situs inversus also have __ problems including chronic __ because of abnormal __ (__).
-__ are normally present on the __ surface of the __ and may be involved in left-right patterning during gastrulation. |
|
Definition
- situs inversus
- 6000; 8000
- frequently
- respiratory; sinusitis; cilia (kartagener's syndrome)
- cilia; ventral; primitive |
|
|
Term
clinical correlate
-Sometimes, remnants of the __ persist in the sacrococcygeal region.
-The clusters of these pluripotent cells proliferate and form tumors known as __.
-These tumors commonly contain tissues from all __.
-This is the most common tumor in __, occurring with a frequency of 1 in 37,000.
-These tumors may also arise from __ that fail to migrate to the __. |
|
Definition
- primitive streak
- sarcococcygeal tumors
- three germ layers
- newborns
- primordial germ cells; gonadal ridge |
|
|
Term
the embryonic period
-The embryonic period is also known as the period of __.
-This is the time when each of the __ gives rise to specific tissues and organs.
-By the end of the embryonic period, the main __ have been established.
-The main features of the external body are recognizable by the end of the second month. |
|
Definition
- organogenesis
- three germ layers (ectoderm, mesoderm, and endoderm)
- organ systems
- second month |
|
|
Term
-At the beginning of the third week of development, the __ has the shape of a disc that is broader in the __ region than in the __ region.
-The appearance of the notochord and prechordal mesoderm induces the overlying __ to thicken and form the __.
-Cells of the plate make up the __, and their induction initiates the process of __ |
|
Definition
- ectodermal germ layer; cephalic; caudal
- ectoderm; neural plate
- neuroectoderm; neurulation |
|
|
Term
neurulation
-Once induction has occurred, the elongated __ gradually expands toward the __.
-By the end of the third week, the lateral edges of the __ become more elevated to form __, and the depressed midregion forms the __.
-Gradually the neural folds grow toward each other in the midline, where they __.
-Fusion begins in the __ region and proceeds __ and __.
-This fusion results in the formation of the __.
-Until fusion is complete, the __ and __ ends of the neural tube remain open and communicate with the amniotic cavity by way of the __ and __ |
|
Definition
- neural plate; primitive streak
- neural plate; neural folds; neural groove
- fuse
- cervical; cranially; caudally
- neural tube
- cephalic; caudal; cranial; caudal neurophores |
|
|
Term
neurulation
-Closure of the cranial neuropore occurs at approximately __*, and closure of the caudal neuropore occurs at day ___*.
-__ is then complete and the central nervous system is represented by a closed tubular structure with a narrow caudal portion, which forms the spinal cord, and a much broader cephalic portion characterized by a number of dilations called the __. |
|
Definition
- day 25; day 27
- neurulation; brain vesicles |
|
|
Term
-As the __ elevate and fuse, cells at the lateral border or crest of the __ begin to dissociate from their neighbors.
-This cell population, the __, will undergo an __-to-__ transition as it leaves the neuroectoderm by active migration and displacement to enter the underlying mesoderm.
-Note: Mesoderm refers to cells derived from the __ and ___. __ refers to loosely organized embryonic connective tissue regardless of origin** |
|
Definition
- neural folds; neuroectoderm
- neural crest; epithelial; mesenchymal
- epiblast; extraembryonic tissues; mesenchyme |
|
|
Term
neural crest cells
- Intermediate levels of __ induce neural crest formation.
-__ (previous) also regulate the migration, proliferation, and differentiation of __ |
|
Definition
- BMP
- BMPs; neural crest cells |
|
|
Term
clinical correlate: neural tube defects
-Neural tube defects result when the neural tube fails to __.
-If the neural tube fails to close in the cranial region, the defect is called __.
-If the neural tube fails to close anywhere from the cervical region caudally, the defect is called __.
-Neural tube defects can be prevented if women take __ of ___ daily, beginning 3 months prior to conception. |
|
Definition
- close
- anencephaly
- spina bifida
- 400 micrograms; folic acid |
|
|
Term
ectodermal derivatives
-The ectodermal germ layer gives rise to organs and structures that maintain contact with the outside world:
-It also gives rise to __ glands, the __ glands, the __ gland, and the __ |
|
Definition
- CNS; peripheral nervous system; sensory epithelium of the ear, nose, and eye; epidermis including hair and nails
- subcutaneous; mammary; pituitary; enamel of the teeth |
|
|
Term
derivatives of the mesoderm germ layer
-Initially, cells of the mesoderm form a thin sheet on either side of the midline.
-Around the 17th day, cells close to the midline proliferate and form a thickened plate of tissue known as __.
-More laterally, the mesoderm layer remains thin and is known as the __.
-The lateral plate divides into two layers:
--__ or __
--__ or __ |
|
Definition
-
- paraxial mesoderm
- lateral plate
-
-- somatic or parietal mesoderm
-- splanchnic or visceral mesoderm |
|
|
Term
derivatives of the mesoderm germ layer
-Somatic/parietal mesoderm is a layer that is continuous with mesoderm covering the __.
-Splanchnic/visceral mesoderm is a layer that is continuous with mesoderm covering the __.
-Together, these layers line a newly formed cavity, the __, which is continuous with the extraembryonic cavity on each side of the embryo.
-__ connects paraxial and lateral plate mesoderm. |
|
Definition
- amnion
- yolk sac
- intraembryonic cavity
- intermediate mesoderm |
|
|
Term
derivatives of the mesoderm germ layer
-By the beginning of the third week, __ begins to be organized into segments.
-These segments, known as __, first appear in the cephalic region of the embryo.
-Their formation proceeds in a __ direction.
-Somitomeres further organize into __.
-__(previous) ultimately differentiate into __ and __, __, and __.
-Since somites appear in with a specified periodicity, the age of an embryo can be accurately determined by __ (see Table 6.2, p. 77) |
|
Definition
- paraxial mesoderm
- somitomeres
- cephalocaudal
- somites
-somites; vertebrae; ribs; muscles; dermis
- counting somites |
|
|
Term
| Neural crest cells form the following: |
|
Definition
-Connective tissue and bones of the face and skull
-Cranial nerve ganglia
-C cells of the thyroid gland
-Conotruncal septum of the heart
-Odontoblasts
-Dermis in the face and neck
-Dorsal root ganglia
-Sympathetic chain ganglia and preaortic ganglia
-Parasympathetic ganglia of the GI tract
-Adrenal medulla
-Schwann cells
-Glial cells
-Meninges of the forebrain
-Melanocytes
-Smooth muscle cells of blood vessels in face and forebrain |
|
|
Term
derivatives of the mesoderm germ layer
-__ splits into parietal and visceral layers, which line the __ cavity and surround the __, respectively.
-Mesoderm from the parietal layer, together with overlying __, will form the __ and __.
-The visceral layer and embryonic endoderm will form the wall of the __.
-Mesodermal cells of the __ layer surrounding the intraembryonic cavity will form thin membranes, the __ membranes, or __ membranes, which line the pleural, pericardial, and peritoneal cavities.
-Mesodermal cells of the __ layer will form a thin serous membrane around each organ. |
|
Definition
- lateral plate mesoderm; intraembryonic cavity; organs
- ectoderm; lateral; ventral body wall
- gut
- parietal; mesothelial membranes; serous membranes
- visceral |
|
|
Term
derivatives of mesoderm germ layer
-Blood vessels form in two ways:
--__, where vessels arise from blood islands.
--__, where vessels arise by sprouting from existing vessels.
-The first blood islands appear in mesoderm surrounding the wall of the yolk sac at 3 weeks of development and slightly later in lateral plate mesoderm.
-These islands arise from mesoderm cells that are induced to form __, a common precursor for vessel and blood cell formation.
-__(previous) are induced by __, which is secreted by surrounding mesoderm cells. |
|
Definition
-
-- vasculogenesis
-- angiogenesis
-
- hemangioblasts
- hemangioblasts; vascular endothelial growth factor (VEGF) |
|
|
Term
derivatives of endoderm germ layer
-The __ is the main organ system that is derived from the endodermal germ layer.
-This germ layer covers the ventral surface of the __ and forms the root of the __.
-With the development and growth of the brain vesicles, the embryonic disc begins to bulge into the __ cavity and to fold cephalocaudally.
-This folding is most pronounced in the __ and __ regions, where the __ fold and __ fold are formed. |
|
Definition
- gastrointestinal tract
- embryo; yolk sac
- amniotic cavity
- head; tail; head; tail |
|
|
Term
derivative of the endodermal germ layer
-As a result of the cephalocaudal folding, a continuously larger portion of the endoderm-lined cavity is incorporated into the body of the embryo.
-In the anterior part, the endoderm forms the __.
-In the tail region, the endoderm forms the __.
-The part between the foregut and hindgut is the __.
--The __(previous) temporarily communicates with the __ by way of a broad stalk, the __. |
|
Definition
- foregut
- hindgut
- midgut
-- midgut; yolk sac; vitelline duct |
|
|
Term
derivatives of the endoderm germ layer
-At its cephalic end, the foregut is temporarily bounded by an ectodermal-endodermal membrane called the __.
-In the fourth week, the __ (previous) ruptures, establishing an open connection between the __ and the __.
-The hindgut also terminates temporarily at an ectodermal-endodermal membrane, the __, which breaks down in the seventh week to create the opening for the anus. |
|
Definition
- buccopharyngeal membrane
- buccopharyngeal membrane; amniotic cavity; primitive gut
- clocal membrane |
|
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Term
| derivatives of the endodermal germ layer: |
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Definition
-The endodermal germ layer initially forms the epithelial lining of the primitive gut and the intraembryonic portions of the allantois and vitelline duct.
-Later, it gives rise to:
--The epithelial lining of the respiratory tract.
--The parenchyma of the thyroid, parathyroids, liver and pancreas.
-The reticular stroma of the tonsils and thymus.
-The epithelial lining of the urinary bladder and urethra.
-The epithelial lining of the tympanic cavity and auditory tube. |
|
|
Term
fetal development
- __: Beginning of ninth week to birth
- Maturation of __ and __
-Growth of the body
--Growth in length predominates early
--Increase in __ last 2 ½ months
-Length of gestation
-__ days or __ weeks from last normal menstrual period
-__ days or __ weeks from fertilization |
|
Definition
- fetal period
- organs and tissues
-
--
-- weight
-
-- 280; 40 weeks
-- 266; 38
--
-- |
|
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Term
fetal development
- slowdown in __ relative to rest of body |
|
Definition
|
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Term
third month
-__ becomes more human looking
--__ move to ventral aspect of face
--__ move close to their final position
-__ reach relative length in relation to body length
--__ remains a little behind
-__ appear in skull and long bones
-__ develop to point where sex can be determined by external examination
-__ withdraw into abdomen from umbilical cord
-__ activity is present |
|
Definition
- face
-- eyes
-- ears
- limbs
-- lower limb
- primary ossification centers
- external genitalia
- intestinal loops
- muscular |
|
|
Term
fourth and fifth
- __ lengthens rapidly
--__ length is about 15 cm
-__ increases little: Still <500 g
-Covered with __
--Eyebrows and head hair present
-During the __, the mother can feel fetal movement |
|
Definition
- fetus
-- crown-rump
- weight
- fine hair (lanugo hair)
--
- fifth month |
|
|
Term
sixth and seventh month
- Skin is __ and __
--Lack of underlying __
-Fetus at the edge of __
--__ and __ are still too immature
--By the end of 7th month
---Length 25 cm, weight 1100 g
---Now has high chance of survival |
|
Definition
- reddish; wrinkled
-- connective tissue
- viability
-- respiratory; cns |
|
|
Term
eights and ninth month
-__ increases
--Deposition of __
--Rounder contours
-At end of gestation
--Skin covered by a white fatty substance from the secretory products of __, called __
--__ has the largest circumference of all body parts
--Normal fetus: 3000-3400 g, CHL 50 cm, CRL 36 cm |
|
Definition
-weight
-- subcutaneous fat
--
-
-- sebaceous glands; vernix caseosa
-- head
-- |
|
|
Term
time of birth
-Most accurate: __ days after fertilization
--Usually difficult to determine
-Fairly accurate: __ days from first day of last normal menstrual period
--Inaccuracies from irregular periods or erosive activity of __ blastocyst causing bleeding
-Most fetuses are born within 10-14 days of calculated date
--If born much earlier, they are categorized as __
--If born later, __ |
|
Definition
- 266
--
- 280
-- implanting
-
-- premature
-- postmature |
|
|
Term
Time of birth
-__ is used commonly to help manage pregnancies
--Measurements made by ultrasound are highly accurate in determining fetal age
--Accurate to within 1-2 days prior to 16 weeks
---CRL
--After 16 weeks, a composite of several measurements
---Biparietal diameter, head circumference, abdominal circumference, femur length |
|
Definition
|
|
Term
fetal membranes and placenta
-Demand for nutritional and other factors grows as the __ grows
-__ changes to meet these requirements
-Increased __ production also changes the configuration of the fetal membranes |
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Definition
- fetus
- placenta
- amniotic fluid |
|
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Term
trophoblast
-Numerous small extensions grow out from the __ forming the __ that extend into the intervillous spaces
--Initially primitive in configuration
--Reconfigure so that fetal and maternal circulation are separated by only the __ and the __ |
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Definition
- stem villi; free villi
--
-- endothelial wall; syncytium |
|
|
Term
chorion
-Initially, villi cover the entire surface of the __
-As pregnancy advances, the villi continue to grow and expand on the __ becoming the __
-Villi on the __ degenerate (__) |
|
Definition
- chorion
- embryonic pole;chorion frondosum
- abembryonic pole; (chorion leave) |
|
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Term
decidua
-These changes are also reflected in the __
--The __ is adjacent to the chorion frondosum and consists of large cells with abundant __ and __
--The __ over the abembryonic pole stretches and degenerates as pregnancy progresses
---The __ leave eventually contacts the __ and fuses with it obliterating the uterine cavity |
|
Definition
- decidua
-- decidua basalis; lipid; glycogen
-- decidua capsularis
--- chorion; uterine wall (decidua parietalis) |
|
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Term
-The only part of the chorion participating in exchange between maternal and fetal circulation is the __
-Together the __ and the __ make up the placenta
-The __ also expands with continuation of pregnancy and eventually obliterates the __ with fusion of the amnion and chorion into the amniochorionic membrane |
|
Definition
- chorion frondosum
- chorion frondosum; decidua basalis
- amniotic cavity; chorionic cavity |
|
|
Term
structure of placenta
-Formed by the beginning of the 4th month
Fetal part: __
Maternal part: __
Fetal side: ___
Maternal side: __
-4th and 5th month: __ form
--Projections of decidua into the intervillous spaces
--Don’t reach __
--Divides the placenta into __ |
|
Definition
-
-- chorion frondosum
-- decidua basalis
-- chorionic plate
-- decidual plate
- decidual septa
--
-- chorionic plate
-- cotyledons |
|
|
Term
- full term placenta
--15-25 cm diameter, 3 cm thick
--500-600 g
--15-20 __
--Umbilical cord attached near center
--Expelled from the uterus about __ after birth of child |
|
Definition
--
--
-- cotyledons
--
-- 30 minutes |
|
|
Term
placental circulation
-__ supply the placenta
-Blood circulates through the __ bathing the villi then exits through __ back at the __
--__ contain about 150 ml of blood
--Replenished 3-4 times per minute
-Placental exchange occurs in those villi where __ are in close contact with the __ covering the villous |
|
Definition
- 80-100 spiral arteries
- intervillous spaces; endometrial; decidual plate
-- intervillous spaces
--
- fetal capillaries; syncytium |
|
|
Term
function of placenta: exchange of gases
-Gases are exchanged by simple __
-Fetus extracts 20-30 ml of __ per minute
-Even short-term interruption of __ delivery is fatal to a fetus
-__ is critical to oxygen delivery |
|
Definition
- diffusion
- oxygen
- oxygen
- placental blood flow |
|
|
Term
function of placenta
-Exchange of __ and __
--Amino acids, free fatty acids, carbohydrates, vitamins
-Transmission of maternal __
-- includes __ and __ immunity |
|
Definition
- nutrients; electrolytes
--
- antibodies
-- IgG; passive immunity |
|
|
Term
function of placenta: hormone production
- hormones are synthesized in the __
- placental hormones include: |
|
Definition
- synctiotrophoblast
- progesterone; estrogenic hormones, primarily estriol; human chorionic gonadotropin; somatomammotropin (formerly placental lactogen) |
|
|
Term
function of placenta: hormone production
-Hormones are synthesized in the __
-Progesterone
--Can support the pregnancy without the __ by end of __ month
--Estrogenic hormones, predominately estriol
--__ growth and __ development
-Human chorionic gonadotropin
--Secreted in early pregnancy to support the __
-Somatomammotropin (formerly placental lactogen)
--Fetal priority for maternal __
--Makes mother __
--__ development and __ production
--__ hormone-like |
|
Definition
-syncytiotrophoblast
-
-- corpus luteum; 4th
-
-- uterine; mammary gland
-
--corpus luteum
-
-- blood glucose
-- diabetogenic
-- breast; milk
-- growth |
|
|
Term
umbilical cord
-Primitive umbilical ring is the oval line of reflection between the __ and the __
- contains:
-- __: allantois, umbilical vessels
-- __: vitelline duct and vessels
--canal connecting the __ and __ |
|
Definition
- amnion; embryonic ectoderm
-
-- connecting stalk
-- yolk stalk
-- extraembryonic; intraembryonic cavities |
|
|
Term
umbilical cord
-As the amniotic cavity expands, the amnion begins to envelope the connecting stalk and yolk stalk forming the __
-Eventually, only the __ surrounded by __ (a type of mucous tissue) make the umbilical cord |
|
Definition
- primitave umbilical cord
- umbilical vessels; wharton's jelly |
|
|
Term
amniotic fluid
-The amniotic cavity is filled with a clear, watery fluid derived primarily from __
--__ at 10 weeks
--__ ml at 20 weeks
--__ at 37 weeks
-During early months, the embryo is suspended by its __ in the amniotic fluid |
|
Definition
- maternal blood
--30ml
--450ml
--800-1000 ml
- umbilical cord |
|
|
Term
amniotic fluid
- The fluid acts to:
--Absorb jolts
--Prevent adherence of the embryo to the __
--Allow fetal movements
-Replaced every __
-Starting in the 5th month, the fetus drinks about __ per day
-__ is added to the fluid |
|
Definition
-
--
-- amnion
--
- 3 hours
- 400ml
- fetal urine |
|
|
Term
twins: dizygotic twins
-__ of twins are dizygotic, or fraternal
-7 to 11 per 1000 births, increases with __
-Ovulation and fertilization of two __
-Implant separately in __
-Each has its own __ and membranes
--Sometimes the __ or less commonly the placentas come into apposition and fuse |
|
Definition
- 2/3
- maternal age
- oocytes
- uterus
- placenta
-- chorionic sacs |
|
|
Term
twins: monozygotic
-Develop from a single fertilized __
-3-4 per 1000 births
-Splitting of the __ at various stages of development
--May split as early as the __
---Two separate zygotes develop with their own __ and __ |
|
Definition
- oocyte
-
- zygote
-- two-cell stage
--- placentas; membranes |
|
|
Term
Twins
-Splitting may occur at the early __ stage
--__ splits within same blastocyst cavity
---Common __ and __; separate __ cavities (monochorionic, diamniotic)
-Separation at the __ stage, prior to appearance of the __
--Monochorionic, monoamniotic |
|
Definition
- blastocyst
-- inner cell mass
--- placenta; chorion; amniotic
- bilaminar germ disc; primitive streak |
|
|
Term
| __ are rare, 1 per 7600 pregnancies |
|
Definition
|
|
Term
twins: problems
-High __ and __
--12% of premature infants are twins
--Usually small at birth
--Prematurity and low birth weight result in increased mortality
-Vanishing twin
-Twin transfusion syndrome
-Obstetrical complications at delivery |
|
Definition
|
|
Term
Twins: conjoined (siamese) twins
- __ stage splitting
--Partial splitting of the __ and __
-Classified by nature and degree of union |
|
Definition
- later
-- primitive node; streak |
|
|
Term
Parturition (birth)
-Factors initiating labor are not known
-“Retreat from maintenance of pregnancy”
--Withdrawal of supporting factors
--Active induction by stimulatory factors
-Labor is divided into three stages
--Stage 1: __ and __
--Stage 2: delivery of __
--Stage 3: delivery of __ and __ |
|
Definition
-
-
--
--
-
-- effacement; dilation of cervix
-- fetus
-- placenta; membranes |
|
|
Term
birth defects
-40-60% are of __
--Genetic factors: 15%
--Environmental factors: 10%
--Combination genetic and environmental: 20-25%
--Twinning: 0.5-1% |
|
Definition
|
|
Term
birth defects
-Minor anomalies occur in 15% of newborns
--Small ears, pigmented spots, short palpebral fissures
M--ay be a clue to a major defects
---1 minor, 3% have major
--2 minors, 10%
--3 minors, 20%
--__ anomalies are especially important indicators |
|
Definition
|
|
Term
types of abnormalities
-__: Complete or partial absence of a structure or alterations of its normal configuration
--Most originate during __ of gestation
-__: Morphological alteration of an already formed structure by a destructive process
-__: Mechanical forces mold a part of the fetus over time, Often musculoskeletal |
|
Definition
- malformation
-- 3rd-8th week
- disruption
- deformation |
|
|
Term
types of abnormalities
-__: Group of anomalies occurring together that have a specific common cause
--Risk of __ is known
-__: Non-random appearance of two or more anomalies that occur more frequently than by chance alone, but the cause has not been determined |
|
Definition
- syndrome
-- recurrence
- association |
|
|
Term
-__ factors can cause birth defects
--In the 1940s, it was discovered that __ infections early in pregnancy caused birth defects
--In 1961, limb defects were linked to use of __
--Many agents have now been identified as teratogens |
|
Definition
- environmental
-- rubella
-- thalidomide |
|
|
Term
principles of teratology
-Susceptibility to teratogenesis depends on the genotype of the conceptus and the maternal genome
-Susceptibility to teratogens varies with developmental stage at the time of exposure
-Manifestations depend on dose and duration of exposure
-Teratogens have specific mechanisms to initiate pathogenesis
-Manifestations of abnormal development are death, malformation, growth retardation, and functional disorders |
|
Definition
|
|
Term
male mediated teratogenesis
-Exposure to chemicals and other agents can cause mutations in male germ cells
-Advanced paternal age is a factor for limb and neural tube defects, Down syndrome, and new autosomal mutations
-Paternal exposures have been linked to spontaneous abortion, low birth weight, and birth defects |
|
Definition
|
|
Term
-__:High frequency sound waves reflected from tissues to make images
--Transabdominal or transvaginal
--Fetal age and growth, structural abnormalities, amniotic fluid volume, blood and fluid flow, multiple gestations
--Neural tube defects, abdominal wall defects, heart defects, facial defects |
|
Definition
|
|
Term
maternal serum screening: Biochemical markers of fetal status
-__, __
--Neural tube defects have high levels
--Down syndrome has slightly lower levels
--Others
---Abdominal wall defects
-Hormone levels: hormone __ |
|
Definition
- afp; alpha-fetoprotein
- hormone hCG |
|
|
Term
- __:Needle inserted transabdominally and amniotic fluid is withdrawn
-->14 weeks gestation
--1% risk of fetal loss
-Fluid and cells for biochemical and genetic analysis: |
|
Definition
- amniocentesis
- afp; karyotype; and enzyme/single gene levels |
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