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The Cell
Cell
83
Histology
Professional
09/24/2011

Additional Histology Flashcards

 


 

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Term
Perinuclear cistern
Definition
space in between the nuclear envelope
Term
Nuclear envelope structure ...
1- is represented by
2- is actually
Definition
1- two unit membranes separated by a space called perinuclear cistern
2- a single unit membrane enclosing the nuclear content and folded upon itself
Term
Nucleoplasmic surface of the nuclear evnvelope is reinforced by
Definition
fibrous lamina
Term
fibrous lamina is composed of what?
Definition
nuclear lamins
Term
At intervals, the outer envelope is continuous with the organelle ______
Definition
granular endoplasmic reticulum
Term
What are the "openings" in the nuclear envelope that are sites of transport of substances in and out of the nucleus?
Definition
nuclear pores; not considered open channels
Term
rod-like structure storing genetic information of the nucleus that are visible w/ by light microscopy ONLY in dividing cells
Definition
chromatin
Term
fine particulate matter of chromosomes in non-dividing cells(interphase cells)
Definition
chromatin
Term
Appearance of chromatin when viewed w/ EM?
Definition
string of beads
Term
each bead on a chromatin strand
Definition
nucleosome
Term
DNA coiled around a core of protein in chromatin
Definition
histone
Term
metabolically active form of chromatin where gene transcription results in the formation of RNA
Definition
euchromatin
Term
The 3 types of RNA
Definition
1- ribosomal RNA (rRNA)
2- messenger RNA (mRNA)
3- transfer RNA (tRNA)
Term
sections of euchromatin is or is not visible in LM?
Definition
not visible; it's largely colorless in H&E sections
Term
metabolically inactive form of chromatin
Definition
heterochromatin
Term
Structure of heterochromatin
Definition
macromolecules are coiled upon themselves and gene transcription doesn't take place; accounts for a high degree of basophilic staining
Term
Chromosomes
Definition
A more condensed and more intense and orderly structure than heterochromatin that is also metaboliccaly inactive
Term
chromatid
Definition
symmetric half of a chromosome
Term
The point where two symmetric halves of chromosomes (chromatids) are joined
Definition
centromere
Term
a dense, rod-like structure located adjacent to the nuclear envelope in non-dividing cells that represents a sex chromosome in cells of females
Definition
Barr body
Term
the complete set of chromosomes of a cell
Definition
karyotype
Term
basophilic body inside a nucleus that represent macromolecular complex of rRNA and protein
Definition
nucleolus
Term
e- lucent area of nucleolus (nucleolar organizer DNA regions)
Definition
sites where genes of specific chromosomes are transcribing for rRNA
Term
e- dense areas (pars fibrosa)
Definition
accumulations of transcripts of rRNA genes
Term
pars granulosa (granular regions)
Definition
accumulations of RNA and maturing subunits of ribosomes
Term
Which organelle is responsible for the synthesis of rRNA and ribosomal subunits?
Definition
nucleolus
Term
What may be absent in cells that are inactive in protein synthesis?
Definition
nucleoli
Term
nonmembranous organelles consisting of macromolecular complexes of rRNA and protein
Definition
ribosomes
Term
Where is the protein component of ribosomal subunits synthesized?
Definition
cytoplasm
Term
a group of ribosomes held together by a strand of elongated molecule of mRNA
Definition
polysome
Term
Where are most ribosomes attached?
Definition
the surface of rough ER or grouped into polysomes
Term
RNA content of ribosomes has a strong affinity for what stains?
Definition
basic dyes and hematoxylin; areas of cytoplasm rich in ribosomes exhibit basophilia
Term
cytoplasmic proteins are synthesized by?
Definition
Polysomes; e.g. the protein of hemoglobin in developing red blood cells and the contractile filaments of muscle cells
Term
Proteins destine for export or inclusion in membranous organelles are synthesized by?
Definition
Ribosomes attached to the rough ER
Term
flattened cisternae w/ ribosomes attached to their external surface (facing the cytoplasm)
Definition
Rough endoplasmic reticulum (rER or granular ER
Term
concentrations of rER visible w/ LM w/ basophilic staining
Definition
ergastoplasm
Term
all protein synthesis beings with...
Definition
cytoplasmic polyribosomes that become attached to the ER upon recognition that the protein to be synthesized is destined for containment w/in cisternae of the ER
Term
Structure of agranular (smooth) ER
Definition
meshwork of anatomosing tubules w/out ribosomes; exhibit acidophilia (eosinophilic) when present in large concentrations
Term
organelle that functions in lipid metabolism including the synthesis of steroid hormones and lipoproteins, detoxification of lipid soluble substances
Definition
Smooth ER
Term
organelle that is the source of phospholipids for replenishing unit membrane
Definition
Smooth ER
Term
Smooth ER in cross-striated muscle is specialized for what?
Definition
sequestering calcium ions and important for initiating contraction
Term
system of flattened membrranous sacs in a stacked configuration that doesn't stain w/ hematoxylin or eosin
Definition
Golgi apparatus; negtive appearance (white) in H&E stain
Term
proteins and polypeptides from the rER are conveyed by transport vesicles to the _____ face of the GA
Definition
forming
Term
glycosylation and sulfation
Definition
glycosylation- addition of carbohydrates
sulfation- addition of sulfate
Modifications that occur at forming face of GA
Term
proteins destined for export undergo concentration in _____ _____ of the GA
Definition
condensing vacuoles
Term
limited vesicles originating from the GA containing hydrolytic or digestive enzymes
Definition
Lysosomes
Term
what is found in all lysosomes?
Definition
acid phosphatase, a "marker" enzyme
Term
what protects the lysosomal membrane agasint digestion?
Definition
luminal coating of sugar molecules attached to integral proteins
Term
lysosomes have the capability of digesting organelles and other cytosolic components by a process known as?
Definition
autophagy
Term
debris-filled vesicles that contain undigestible products that collect over the cell's life
Definition
residual bodies
Term
residual bodies in a neuron
Definition
lipofuscin granules or aging pigments
Term
storage diseases where cells accumulate materials that normally would have been digested are due to what?
Definition
defective lysosomal content
Term
membrane limited microbodies primarily associated w/ the beta-oxidation of long chain fatty acids producing acetyl CoA for cellular metabolism, metabolism of alcohol, amino acids, and drugs, and synthesis of bile and cholesterol.
Definition
Peroxisomes
Term
spherical or oblong-shaped organelle found in all cells except red blood cells; comprised of a double unit membrane
Definition
mitochondria (structure)
Term
numerous folds formed by the invagination of inner mitochondrial membrane to increase the surface area for metabolic processes
Definition
cristae
Term
Organelle that synthesizes ATP molecules and provide energy for the synthetic processes of the cell
Definition
Mitochondria
Term
process of synthesizing ATP which utilizes substrates originating from the cytoplasm and mitochondrial enzymes in the matrix
Definition
oxidative phosphorylation
Term
what is responsible for the maintenance of internal ionic environment of mitochondria?
Definition
calcium granules
Term
monomers of actin that often form bundles which is considered to be the mechanism for cell motion, changes in shape, cytoplasmic streaming, movement of the cell membrane, and serves as an element of the cytoskeleton
Definition
microfilaments
Term
____ are finger-like projections stabilized by bundles of microfilaments that increase SA for transport and absorption of molecules across the cell membrane
Definition
microvilli
Term
filaments of a similar chemical composition that are associated w/ specific cell types and is an important element of the cytoskeleton
Definition
intermediate filaments
Term
hollow, slender tubes composed of molecules of tubulin that have a dynamic feature.
Definition
microtubules
Term
Functions of microtubules
Definition
1. Cytoskeleton support
2. intracellular transport of vesicles
3. movement of the cell- sliding of microtubules along each other
Term
"motor" protein that links vesicles to microtubules to produces anterograde motion(towards + end of microtubules)
Definition
kinesin
Term
"motor" protein that links vesicles to microtubules to produces retrograde motion(towards - end of microtubules)
Definition
dynein
Term
hollow cylinder consisting of a wall that is composed of 9 triplets of short microtubules
Definition
centriole
Term
pair of centrioles
Definition
centrosome
Term
Functions of centrioles
1. Cell center
2. source of micro tubules
3. source of cilia
Definition
1. represent a point around which activities associated w/ cell division are centered
2. new microtubules are assembled from tublin molecules in the vicinity of centrioles which is essential for forming mitotic spindle and microtubules in newly formed daughter cells
3. Direct the formation of microtubules forming cilia
Term
Long microtubules assembled in 9 doublets with an additional pair of microtubules in the center and a centrosome at the base
Definition
Cilia
Term
Function of Cilia
Definition
propel fluid (in uterine tube) or mucus (trachea) along the epithelial surface by beating back and forth in a synchronized, orderly manner
Term
end products of cellular metabolism that do NOT participate in energy production, synthesis of proteins, movement of materials, etc. Passive substances that depend on organelles for subsequent fate
Definition
Inclusions (of endogenous origin)
Term
Condensation of chromatin, nucleolus disappears,paired centrioles move to opposite poles of the cell and coordinate formation of microtubules
Definition
Prophase
Term
Nuclear membrane breaks down, microtubules of the spindle attach to chromosomes at kinetochore in the centromere, chromosomes migrate toward the equatorial region of spindle
Definition
Prometaphase
Term
Chromosomes are maximally condensed and are positioned at the equator of the spindle
Definition
Metaphase
Term
chromosome divide and daughter chromosomes migrate toward the opposite poles of the spindle
Definition
Anaphase
Term
chromatids uncoil, nuclear envelope forms, plasma membranes develop cleavage furrow, and cytokinesis occurs
Definition
Telophase
Term
Eosin(E) stains stains (acidophilic/basophilic) structures pink to red color because the structure is more (acidic/basic)
Definition
Eosin(E) stains stains (acidophilic) structures pink to red color because the structure is more (basic)
Term
Hematoxylin(H) stains stains (acidophilic/basophilic) structures blue to purplish color because the structure is more (acidic/basic)
Definition
Hematoxylin(H) stains stains (basophilic) structures blue to purplish color because the structure is more (acidic)
Term
_____ staining is a staining technique to detect the presence of particular chemical groups, as revealed by predictable color reactions
Definition
Histochemical
Term
Immunocytochemistry
Definition
an antibody labeled with a fluroescent dye reacts w/ a specific cellular macromolecule which represents the antigen. Locations of fluorescence represent the sites of distribution of antigen
Term
Programmed cell death that occurs as a normal consequence of growth and development when a population of cells has no further function.
Definition
apoptosis
Term
What occurs during these stages of apoptosis?
1. DNA fragmentation
2. cytoplasmic changes
3. loss of mitochondrial function
4. Membrane blebbing
5. formation of apoptotic bodies
Definition
1. onset of cell death and activation of nuclear endonucleases. Karyolysis (dissolution) and karyorrhexis (fragmentation) of DNA molecules
2. reduction of cell volume and clumping of cytoskeletal elements and ribosomes
3. Failure of e- transport, ATP production, and release of cytochromes into cytoplasm
4. changes in the components of cell membrane and cytoskeletal elements causing the cell to bud
5. cluster of membrane-limited vesicles containing remnants of nucleus and cytoplasm that will be phagocytosed
Term
accidental or induced cell death brought about by irreversible cell injury; cellular swelling usually occurs and rupture of cell membrane w/ release of cell contents
Definition
necrosis
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