Shared Flashcard Set

Details

Block 1
Gametogenesis to Implanation, Gastrulation & Neurulation, Musculoskeletal Development, Limb Development
45
Anatomy
Graduate
08/20/2011

Additional Anatomy Flashcards

 


 

Cards

Term

 

 

 

 

In what portion of the uterus does implantation usually occur?

Definition

 

 

 

 

The Posterior upper third of the uterus

Term

 

 

 

 

The Cytotrophoblast develops into the __________
 after the zygote meets the uteran wall.

Definition

 

 

 

 

syncytiotrophoblast

Term

 

 

 

Buccopharyngeal membrane, Primitive streak, cloacal membrane, and primitive node (& pit) are all landmarks of what part of the pre-gastrulation embryo?

Definition

 

 

 

 

The Epiblast

Term

 

 

 

 

The cloacal membrane is the future _________

Definition

 

 

 

 

Anus

Term

 

 

 

 

The axes of the embryo are are established before or after gastrulation?

Definition

 

 

 

 

Before gastrulation

Term

 

 

 

 

What is the name given for the formation of 3 germ layers from the Epiblast? What are the germ layers?

Definition

 

 

 

Gastrulation is the formation of ectoderm, mesoderm, and endoderm

Term

 

 

 

What embryological 'major determining event' is the last stage at which twinning can occur?

Definition

 

 

 

 

Gastrulation

Term

Which of the following is NOT correct?

 

A. Mesoderm, Endoderm & Ectoderm refer to germ layers and developmental lineage

B. Mesenchyme (M) and epithelium (E) are histological terms that refer to the form of the tissue

C. Mesenchyme is embryonic epithelial tissue

D. Epithelia are derived from all three germ layers & both neural tube and neural crest

Definition

 

 

 

 

C. Mesenchyme is embryonic connective tissue

Term

 

 

 

Most mesenchyme is mesodermal in origin, but it can also arise from what?

Definition

 

 

 

 

Neural crest (sometimes called ectomesenchyme)

Term

 

 

 

What phase of embryogenesis changes the fate of the epiblast cells so that they become determined?

Definition

 

 

 

 

Gastrulation

Term

 

 

 

Primordial germ cells can be found where and at what week after fertilization?

Definition

 

 

 

 Gametes are derived from primordial germ cells (PGCs) that are formed in the epiblast during the second week and that move to the wall of the yolk sac

Term
During the fourth week after fertilization, primordial germ cells begin to migrate from the yolk sac toward the developing gonads, where they arrive by the end of the fifth week. Mitotic divisions increase their number during their migration and also when they arrive in the gonad. In preparation for fertilization, what process do these cells undergo, which includes meiosis, to reduce the number of chromosomes and cytodifferentiation to complete their maturation?
Definition

 

 

 

 

Gametogenesis

Term
Some evidence suggests that primordial germ cells that have strayed from their normal migratory paths could be responsible for some of the tumors found in a patient. Another source is epiblast cells migrating through the primitive streak during gastrulation. What type of tumors does this patient have?
Definition



Teratomas; these are tumors of disputed origin that often contain a variety of tissues, such as bone, hair, muscle, gut epithelia, and others.

Term

 

 

A tumor is found in a patient. It is thought that this tumor could arise from a pluripotent stem cell that can differentiate into any of the three germ layers or their derivatives. What type of tumor is this?

Definition

 

 

 

 

Teratoma

Term

 

 

During this phase, the chromosomes are extremely long, they are spread diffusely through the nucleus, and they cannot be recognized with the light microscope. What phase of the cell cycle is described?

Definition

 

 

 

 

Replication (S)

Term

 

 

 

At what phase of mitosis do the chromatids become distinguishable?

Definition

 

 

 

 

Prometaphase

Term

 

 

 

What marks the beginning of anaphase?

Definition

 

 

 

 

Centromere division of chromosomes

Term

 

 

 

 

At the end of the third week, where could one find the primordial germ cells in an embryo? Where will they migrate towards?

Definition

 

 

 

 

In the wall of the yolk sac; they will migrate towards the developing gonad

Term

 

 

 

What terms are given to male and female germ cells, respectively?

Definition

 

 

 

 

spermatocytes and primary oocytes

Term

 

 

 

What name is given to the process where homologous chromosomes align themselves in pairs in meiosis?

Definition

 

 

 

 

Synapsis

Term

 

 

 

 

What does Meiosis II separate?

Definition

 

 

 

 

Sister Chromatids

Term

 
The approximately 30 to 40 crossovers (one or two per chromosome) with each meiotic I division are most frequent between genes that are closer or farther apart on a chromosome?
Definition

 

 

 

crossovers with each meiotic I division are most frequent between genes that are far apart on a chromosome.

Term

 

 

Segments of chromatids break and are exchanged as homologous chromosomes separate. As separation occurs, points of interchange are temporarily united and form what X-like structure?

Definition

 

 

 

Chiasma

Term

Which of the following is NOT one of the most common chromosomal abnormalities in abortuses (spontaneous abortions)?

 

A. 45,X (Turner syndrome)

B. Cri-du-chat syndrome

C. Trisomy 16

D. Triploidy

Definition

 

 

 

B. Cri-du-chat syndrome

Term

 

 

 

True or False: Abnormalities in chromosome number may originate during meiotic or mitotic divisions.

Definition

 

 

 

 

True

Term

 

In meiosis, two members of a pair of homologous chromosomes normally separate during the first meiotic division, so that each daughter cell receives one member of each pair. Sometimes, however, separation does not occur, and both members of a pair move into one cel. This is known as what?

Definition

 

 

 

 

Non-disjunction

Term
Occasionally, nondisjunction occurs during mitosis (mitotic non-disjunction) in an embryonic cell during the earliest cell divisions.  Affected individuals may exhibit few or many of the characteristics of a particular syndrome, depending on the number of cells involved and their distribution. What is this result  of mitotic non-disjunction called?
Definition

 

 

Mitotic non-disjunctions produce mosaicism, with some cells having an abnormal chromosome number and others being normal.

Term

Which of the following is not a common chromosome for translocations involving down syndrome? Why?

 

A. 13

B. 14

C. 15

D. 16

E. 21

F. 22

 

Definition

 

D;

 

 

Chromosomes 13,14,15,21, and 22 cluster during meiosis

Term

 

 

 

In 75% of trisomy 21 instances, when does non-disjunction occur (in reference to phases of gametogenesis)?

Definition

 

 

 

 

oocyte formation

Term

 

 

 

What is the clinical features of Klinefelter syndrome, which is only found in males and usually detected by puberty?

Definition

 

 

 

Sterility, testicular atrophy, hyalinization of the seminiferous tubules, and usually gynecomastia (abnormally large mammary glands in males)

Term

 

 

 

47 XXY in addition to the presence of a Barr body (in 80% of cases) describes a male or female with what disorder?

Definition

 

 

 

 

A male with Klinfelter's syndrome

Term

 

 

 

Nondisjunction of the XX homologues is the most common causative event in what disorder?

Definition

 

 

 

Klinefelter's syndrome

Term

Which of the following is NOT true?

 

A. Turner syndrome, with a 45,X karyotype, is the only monosomy compatible with life

B. 98% of all fetuses with Turner syndrome are spontaneously aborted

C. Turner syndrome is characterized by the absence of ovaries (gonadal dysgenesis) and short stature

D. In ~40% of affected men, nondisjunction in the female gamete is the cause

Definition

 

 

 

 

D. In ~40% of affected women, nondisjunction in the male gamete is the cause

Term

 

 

 

Patients with ______ syndrome are infantile, with scanty menses and some degree of mental retardation. They have two Barr (sex chromatin) bodies in their cells

Definition

 

 

 

XXX syndrome

Term
A well-known syndrome, caused by partial deletion of the short arm of chromosome 5, is the cri-du-chat syndrome. Such children have what unique syndrome?
Definition

 

 

 

A cat-like cry

Term
Microdeletions, spanning only a few contiguous genes, may result in microdeletion syndrome or contiguous gene syndrome. Sites where these deletions occur, called contiguous gene complexes, can be identified by high-resolution chromosome banding. An example of a microdeletion occurs on the long arm of chromosome 15 (15q11–15q13). Inheriting the deletion on the maternal chromosome results in what disorder?
Definition

 




Angelman syndrome

Term
Microdeletions, spanning only a few contiguous genes, may result in microdeletion syndrome or contiguous gene syndrome. Sites where these deletions occur, called contiguous gene complexes, can be identified by high-resolution chromosome banding. An example of a microdeletion occurs on the long arm of chromosome 15 (15q11–15q13). If the defect is inherited on the paternal chromosome, what syndrome is produced?
Definition





Prader-Willi syndrome

Term

 

 

Characteristics that are differentially expressed depending upon whether the genetic material is inherited from the mother or the father are examples of what concept?

Definition

 

 

 

 

genomic imprinting

Term
Fragile sites are regions of chromosomes that demonstrate a propensity to separate or break under certain cell manipulations. For example, fragile sites can be revealed by culturing lymphocytes in folate-deficient medium. Although numerous fragile sites have been defined and consist of CGG repeats, only the site on which chromosome has been correlated with an altered phenotype, resulting in what disorder?
Definition

 

 

 

The long arm of the X chromosome (Xq27) has been correlated with an altered phenotype and is called the fragile X syndrome

Term
Males are affected more often than females (1 per 1,000 vs. 1 per 2,000), which may account for the preponderance of males among the mentally retarded. What syndrome, which is second only to Down syndrome as a cause of mental retardation, is caused because of chromosomal abnormalities and can explain this preponderance?
Definition

 

 

 

 

Fragile X syndrome

Term

 

 

 

What molecular technique uses specific DNA probes to identify ploidy for a few selected chromosomes?

Definition

 

 

 

 

fluorescence in situ hybridization (FISH)

Term

 

 

 

When (at what point in embryogenesis) can one expect to see oogonia formation?

Definition

 

 

 

Once primordial germ cells have arrived in the gonad of a genetic female, they differentiate into oogonia

Term
 
Oogonia undergo a number of mitotic divisions, and by the end of the third month are arranged in clusters surrounded by a layer of flat epithelial cells. Whereas all of the oogonia in one cluster are probably derived from a single cell, what cells originate from surface epithelium covering the ovary?
Definition

 

 

 

 

The flat epithelial cells, known as follicular cells, originate from surface epithelium covering the ovary.

Term

 

 

By the what month of prenatal development do the total number of germ cells in the ovary reach their maximum, estimated at 7 million?

Definition

 

 

 

 

The 5th month

Term

 

 

 

A primary oocyte, together with its surrounding flat epithelial cells, is known as what structure?

Definition

 

 

 

 

A primordial follicle

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