Gonadogenesis Flashcards

1
Q

shortly after Gastrulation, the presumptive sperm or eggs are called:

  1. Primitive Germ Layer
  2. Presumptive Germ Line
  3. Primordial Germ Cells
A

3.

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2
Q

The week future Germ line can be identified:

  1. After 3 weeks near the mesoderm of the yolk sac
  2. After 4 weeks near the primitive streak
  3. After 5 weeks near the allantois
A

1

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3
Q

What are the Special Features associate with the Germ Line?

A

Germ line characterized by:

  1. Lengthy migration to the gonadal ridge
  2. Erasure of epigenetic information from the previous generation
  3. Reactivation of the X chromosome (inactive X - Barr body)
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4
Q

During PGCs Migration to the genital ridge……………..

A
  1. Appearance in the genital ridge about 8-9 weeks
  2. Proliferation by mitosis
  3. Chemotactic Secretion by the genital ridge
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5
Q

True or false, After population of the genital ridges:

a. Orientation of germinal epithelium into columnar structures called primitive sex chords
b. The SRX gene on the X chromosome is required for female differentiation
c. Expression of the SRY gene on the Y chromosome regulates key gender morphological changes
d. SRY up-regulation promotes the development of the Wolffian Duct
e. SRY up-regulation promotes the development of the Mullerian Duct
f. SRY up-regulation promotes the expression of SOX9 transcription factor
g. SOX9 is required for the activation of AMH/MIS
h. AMH/MIS causes regression of the Mullerian Duct
i. WNT4 (Wills Tumor gene) inhibits mesonephric endothelial migration

A

After population of the genital ridges:

a. Orientation of germinal epithelium into columnar structures called primitive sex chords (true)
b. SRX gene on the X chromosome is required for female differentiation (false)
c. Expression of the SRY gene on the Y chromosome regulates key gender morphological changes (true)
d. SRY up-regulation promotes the development of the Wolffian Duct (true)

e. SRY up-regulation promotes the development of the Mullerian Duct (false)

f. SRY up-regulation promotes the expression of SOX9 transcription factor(true)
g. SOX9 is required for the activation of AMH/MIS (true)
h. AMH/MIS causes regression of the Mullerian Duct(true)
i. WNT4 (Wills Tumor gene) inhibits mesonephric endothelial migration (true)

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6
Q

The default gender is female

A

true

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7
Q

SDF-1 is the main chemotactic substance secreted by the genital ridges

  1. Yes
  2. No
A

1.

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8
Q

The main aim of SDF-1 is to provide a target location for migrating primordial germ cells

  1. Yes
  2. No
A

1.

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9
Q

in males, the PGCs (primordial germ cells) and Coelomic Epithelium developed faster and deeper into medullary mesenchyme to form the Testis Cords.

  1. Yes
  2. No
A

1.

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10
Q

In females, the PGC (primordial germ cells) and Coelomic Epithelium developed slower and less deeply and form small clusters to become the primordial follicles located more towards the ovarian cortex.

  1. Yes
  2. No
A

1.

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11
Q

SRY Initiates Differentiation of Sertoli Cells

  1. Yes
  2. No
A

1

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12
Q

Sertoli Cells are the source of Fibroblast Growth Factor 9 (FGF-9)

  1. Yes
  2. No
A

1

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13
Q

FGF-9 induces the formation of the Testicular Cords (Pre-Seminiferous Tubules) at week ……….?

A

FGF-9 induces the formation of the Testicular Cords (Pre-Seminiferous Tubules) at weeks 7-8

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14
Q
  1. Sertoli cells form clusters around the germ cells
  2. Peritubular myoid cells surround the clusters and create the basal laminar
  3. The Sertoli cells produce AMH/MIS to suppress Mullerian duct development
  4. The wolffian duct is the default development option
  5. The Leydig cells develop in the interstitial regions between the clusters
  6. The blood and lymphatic systems develop inside the clusters
  7. The Leydig cells start to produce testosterone
A
  1. Sertoli cells form clusters around the germ cells (True)
  2. Peritubular myoid cells surround the clusters and create the basal laminar (True)
  3. The Sertoli cells produce AMH/MIS to suppress Mullerian duct development (True)
  4. The wolffian duct is the default development option (Fales)
  5. The Leydig cells develop in the interstitial regions between the clusters (True)
  6. The blood and lymphatic systems develop inside the clusters(Fales)
  7. The Leydig cells start to produce testosterone(True)
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15
Q

the Leydig cells start to produce Testosterone from:

  1. weeks 4-5
  2. weeks 6-7
  3. weeks 8-10
  4. weeks 11-14
A

3.

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16
Q

production of Testosterone from the embryonic testis results in……………….?

A

production of Testosterone from the embryonic testis results in:

  1. establishment of the male phenotype
  2. Growth and differentiation of the Wolffian duct structures
  3. metabolism to dihydrotestosterone
  4. virilization (characteristics of male) of the urogenital sinus and external genitalia by Dihydrotestosterone
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17
Q

The basic format of the testis is laid down by

  1. week 8-12
  2. week 13-15
  3. week 16-20
  4. week 21-25
A

3.

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18
Q

when complete, which of the following are true:

  1. Sertoli cells lie on the basal membrane within the seminiferous tubules
  2. Prospermatogonial cells lie on the basal membrane within the seminiferous tubules
  3. Prospermatogonial cells start to undergo spermatocytogenesis
  4. The seminiferous tubules lie within a highly vascular stroma
  5. The vascular stroma contain the leydig cells
  6. All the tubules lie within a fibrous capsule, the tunicia albungine
  7. Development of the testicular size continues slowly until puberty
A

all true except (3)

  1. Sertoli cells lie on the basal membrane within the seminiferous tubules
  2. Prospermatogonial cells lie on the basal membrane within the seminiferous tubules
  3. Prospermatogonial cells start to undergo spermatocytogenesis (false)
  4. The seminiferous tubules lie within a highly vascular stroma
  5. The vascular stroma contain the leydig cells
  6. All the tubules lie within a fibrous capsule, the tunicia albungine
  7. Development of the testicular size continues slowly until puberty
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19
Q

Main testicular events at Puberty………………….

A

Main testicular events at Puberty.

  • the cords canalise an develop into tubules that connect to form the rete testis
  • The ducts connect to the vasa efferentia and the epididymis
  • Leydig cells increase their endocrine secretions
  • The prospermatogonial cells develop into the spermatogeneic epithelium lining
  • The prospermatogonial cells commence mitosis
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20
Q

Testicular descent is controlled by hormones secreted by :

a. Leydig cells
b. Sertoli cells
c. primordial germ celss
d. genital chord

A

1.

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21
Q

Descent is controlled by two ligaments: the suspensory and the gubernaculum. what happens during descent:

  1. Both the suspensory and the gubernaculum elongate
  2. The suspensory elongates and the gubernaculum does not
  3. The gubernaculum elongates and the suspensory does not
A

2.

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22
Q

Regarding the timetable for descent, which is true

  1. The testes have migrated over the pubic bone by weeks 22-26
  2. The testes have migrated over the pubic bone by weeks 24-26
  3. The testes have migrated over the pubic bone by weeks 25-28
  4. The testes have migrated over the pubic bone by weeks 25-32
  5. The testes have migrated into the scrotum by weeks 35-40
  6. The testes have migrated into the scrotum by weeks 35-38
  7. The testes have migrated into the scrotum by weeks 32-36
A

3 and 5

Timetable for descent

  • The testes have migrated over the pubic bone by weeks 25-28
  • Migration into the scrotum by weeks 35-40
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23
Q

The temperature difference between the testes and body temperature is approximately

  1. 0.5ºC
  2. 1ºC
  3. 1.5ºC
  4. 2ºC
A

4.

24
Q

the total length of seminiferous tubules in an adult testis is approximately:

  1. 200m
  2. 300m
  3. 400m
  4. 500m
  5. 1000km
A

1.

25
Q

Morphology and properties of the Seminiferous tubules>>>>>

A

Regarding the morphology of the Seminiferous tubules:

* The tubules are lined with a spermatogenic epithelium

* 4-5 generations of germs exist in the tubules

* The least differentiated are found in the periphery

* The most differentiated are found in the lumen

* Development is wavelike in cross section & in along the tubule

26
Q

Development from spermatogonia to spermatozoon takes approximately

  1. 50 days
  2. 55 days
  3. 60 days
  4. 65 days
A

4.

27
Q

The tubules lie on a delicate a nuclear basement membrane that lies on layer of connective tissue called the

  1. tunica basali
  2. tunica tubularis
  3. tunica propria
A

3.

28
Q

Sertoli cells extend from the periphery to the lumen

  1. Yes
  2. No
A

1.

29
Q

The Sertoli cells are thought to nourish the germ cells via

  1. gap junctions
  2. passive diffusion
  3. exocytosis
  4. gap junctions and passive diffusion
  5. gap junctions and exocytosis
A

1.

30
Q

Mature spermatozoa traverse the epididymis over a period of

  1. 2-12 days
  2. 2-14 days
  3. 2-16 days
  4. 2-18 days
  5. 2-20 days
A

2.

31
Q

Cryptorchidism

A

Undescended Testes

32
Q

hypoplastic

A

Underdeveloped Testes

33
Q

one or both testicles are absent or underdeveloped.

Anorchia

A

Vanished Testes

Vanishing testis syndrome or Testicular regression syndrome (TRS)

is defined as the absence or an incomplete development of the testis

34
Q

one absent or undeveloped tisticle.

Monorchism

A

A Single Testes

35
Q

the testes normally enter the scrotom via the

A

inguinal canal

the testes normally enter the scrotom via the inguinal canal

at 30-34 weeks of pregnancy

36
Q

The incidence at birth for undescended testes is

A

5%

37
Q

Retractile testes

A

The term to describe the event if the cremasteric muscle attached to the testis pulls the testis up into the groin so that it cannot be felt or seen

38
Q

Acquired undescended testes

A

when a boy is born with his testes in the scrotum, they can occasionally move back out of the scrotum and into the groin

39
Q

Undescended testes are usually identified in the age group…..

A

18-39 years

40
Q

Regarding the risk of cancer:

  1. Men with undescended tests have a higher risk of cancer
  2. Men with undescended tests have a higher risk of cancer even after intervention
  3. When one testes has not descended, the contralateral normal tests also has an elevated cancer risk
A

all true

41
Q

A Hernia almost always happens with an undescended testis

A

true

42
Q

The name of the operation to lower Undescended Testes is

A

orchidopexy

this operation performed in adults mainly to prevent cancer development by undescended testes NOT for Fertility results.

so

the best time for Orchidpexy is

>6 months

43
Q

FGF-9 induces the formation of the testicular cords (pre-seminiferous tubules) about:

a. weeks 5-6
b. weeks 7-8
c. weeks 9-10

A

c.)

44
Q

*derived from the surface celomic epithelium of the gonadal ridge:

surface celomic epithelium of the gonadal ridge?

A
  • sustentacular cells of Sertoli
  • follicular cells of the ovary
  • interstitial cells of Leydig
  • cells of kidney
  • cells of adrenal cortex
45
Q

Sertoli cells are the source of Fibroblast Growth Factor 9 (FGF-9).

a. Yes
b. No

A

a)

46
Q

The Leydig cells start to produce testosterone from:

a. weeks 6-7
b. weeks 8-10
c. weeks 11-14
d. weeks 4-5

A

b)

47
Q

The tubules lie on► a delicate a nuclear basement membrane that lies on► layer of connective tissue called the:

a. tunica basalis
b. tunica propria
c. tunica tubularis

A

b)

48
Q
A
49
Q

Regarding the timetable for the testicular descent the major events by weeks

A

Testes migrated over the pubic bone by weeks 25-28

⇒ migrated into the scrotum by weeks 35-40

50
Q

7 FACTSAfter population of the genital ridges:

A
  1. expression of the SRY gene on the Y chromosome regulates key gender morphological changes
  2. SOX9 is required for the activation of AMH/MIS
  3. SRY up-regulation promotes the expression of SOX9 transcription factor
  4. AMH/MIS causes regression of the Mullerian Duct
  5. WNT4 (Wills Tumor gene) inhibits mesonephric endothelial migration
  6. SRY up-regulation promotes the development of the Wolffian Duct
  7. orientation of germinal epithelium into columnar structures called primitive sex chords
51
Q

Which of the following are derived from the surface celomic epithelium of the gonadal ridge?

a. interstitial cells of Leydig
b. epithelial lining of the ductus deferens
c. oogonia
d. follicular cells of the ovary
e. spermatogonia

A

d)

follicular cells of the ovary ►derived from the surface of celomic epithelium of the gonadal ridge

بينما

sustentacular (supporting) cells of Sertoli derived from the ►celomic epithelial cells that formed the primitive sex cords

بصفه عامه

all listed derived from the surface celomic epithelium of the gonadal ridge

  • sustentacular cells of Sertoli
  • follicular cells of the ovary
  • interstitial cells of Leydig
  • cells of kidney
  • cells of adrenal cortex
52
Q

SDF-1 is ……….

A

SDF-1 is

the main chemotactic substance secreted by the genital ridges.

53
Q

Leydig cells start to produce testosterone from:

a. weeks 6-7
b. weeks 8-10
c. weeks 11-14
d. weeks 4-5

A

b)

review the included timetable diagram

54
Q

DEFECT of spermatocytogenesis may be caused by:

Mutation of SYCP 3 gene, …………

  • *AURKC** gene…………
  • *SPATA16** gene………..
A
  • Point mutation of the SYCP 3 gene,

chromosome 12 ♦► - arresting meiosis.

  • Mutations of the gen SPATA16,

chromosome 3 – globozoospermia.

  • Mutations of the gen AURKC, chromosome 19 - large, Abnormal heads.
55
Q

It is know, that there are at least 1,000 “spermatogenesis genes” on Y chromosome and autosomes and X chromosome. Is there anything false?

    • chromosomal anomalies and microdeletions of regions of the azoospermia factor (AZF) of the Y chromosome -⇒ azoospermia
    • Y chromosome microdeletions - idiopathic azoospermia and severe oligozoospermia
    • SPATA 16 mutation, chromosome 3–

⇒ globozoospermia

    • AURKC mutation, 19th chromosome – large, ⇒Abnormal heads
    • USP9Y mutation (Yq11.2) – azoospermia by ⇒hypospermatogenesis
    • RBMY mutations (Yq11.223) – azoospermia by arresting meiosis
    • SYCP 3 mutation, 12th chromosome – azoospermia by ⇒arresting meiosis
    • DAZ mutations (Yq11.23) - various forms of infertility, ranging from ⇒oligozoospermia to azoospermia
    • androgen receptor gene mutations (AR, X-linked, defect in the AR gene (Xq11-12)) – androgen insensitivity syndrome and ⇒spermatogenesis damage
    • CF mutations on the long arm of chromosome 7th at locus 7q31.2 – CFTR ⇒ OA
A

ALL TRUE

IN GENERAL

Spermatogenesis can disrupt by:

chromosomal abnormalities and microdeletions of azoospermia factor (AZF) regions of the Y chromosome

androgen receptor gene mutations (X-linked)

mutations on the long arm of chromosome 7 at locus 7q31.2 (CFTR)