Gonadogenesis Flashcards
shortly after Gastrulation, the presumptive sperm or eggs are called:
- Primitive Germ Layer
- Presumptive Germ Line
- Primordial Germ Cells
3.
The week future Germ line can be identified:
- After 3 weeks near the mesoderm of the yolk sac
- After 4 weeks near the primitive streak
- After 5 weeks near the allantois
1
What are the Special Features associate with the Germ Line?
Germ line characterized by:
- Lengthy migration to the gonadal ridge
- Erasure of epigenetic information from the previous generation
- Reactivation of the X chromosome (inactive X - Barr body)
During PGCs Migration to the genital ridge……………..
- Appearance in the genital ridge about 8-9 weeks
- Proliferation by mitosis
- Chemotactic Secretion by the genital ridge
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
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)
The default gender is female
true
SDF-1 is the main chemotactic substance secreted by the genital ridges
- Yes
- No
1.
The main aim of SDF-1 is to provide a target location for migrating primordial germ cells
- Yes
- No
1.
in males, the PGCs (primordial germ cells) and Coelomic Epithelium developed faster and deeper into medullary mesenchyme to form the Testis Cords.
- Yes
- No
1.
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.
- Yes
- No
1.
SRY Initiates Differentiation of Sertoli Cells
- Yes
- No
1
Sertoli Cells are the source of Fibroblast Growth Factor 9 (FGF-9)
- Yes
- No
1
FGF-9 induces the formation of the Testicular Cords (Pre-Seminiferous Tubules) at week ……….?
FGF-9 induces the formation of the Testicular Cords (Pre-Seminiferous Tubules) at weeks 7-8
- Sertoli cells form clusters around the germ cells
- Peritubular myoid cells surround the clusters and create the basal laminar
- The Sertoli cells produce AMH/MIS to suppress Mullerian duct development
- The wolffian duct is the default development option
- The Leydig cells develop in the interstitial regions between the clusters
- The blood and lymphatic systems develop inside the clusters
- The Leydig cells start to produce testosterone
- Sertoli cells form clusters around the germ cells (True)
- Peritubular myoid cells surround the clusters and create the basal laminar (True)
- The Sertoli cells produce AMH/MIS to suppress Mullerian duct development (True)
- The wolffian duct is the default development option (Fales)
- The Leydig cells develop in the interstitial regions between the clusters (True)
- The blood and lymphatic systems develop inside the clusters(Fales)
- The Leydig cells start to produce testosterone(True)
the Leydig cells start to produce Testosterone from:
- weeks 4-5
- weeks 6-7
- weeks 8-10
- weeks 11-14
3.
production of Testosterone from the embryonic testis results in……………….?
production of Testosterone from the embryonic testis results in:
- establishment of the male phenotype
- Growth and differentiation of the Wolffian duct structures
- metabolism to dihydrotestosterone
- virilization (characteristics of male) of the urogenital sinus and external genitalia by Dihydrotestosterone
The basic format of the testis is laid down by
- week 8-12
- week 13-15
- week 16-20
- week 21-25
3.
when complete, which of the following are true:
- Sertoli cells lie on the basal membrane within the seminiferous tubules
- Prospermatogonial cells lie on the basal membrane within the seminiferous tubules
- Prospermatogonial cells start to undergo spermatocytogenesis
- The seminiferous tubules lie within a highly vascular stroma
- The vascular stroma contain the leydig cells
- All the tubules lie within a fibrous capsule, the tunicia albungine
- Development of the testicular size continues slowly until puberty
all true except (3)
- Sertoli cells lie on the basal membrane within the seminiferous tubules
- Prospermatogonial cells lie on the basal membrane within the seminiferous tubules
- Prospermatogonial cells start to undergo spermatocytogenesis (false)
- The seminiferous tubules lie within a highly vascular stroma
- The vascular stroma contain the leydig cells
- All the tubules lie within a fibrous capsule, the tunicia albungine
- Development of the testicular size continues slowly until puberty
Main testicular events at Puberty………………….
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
Testicular descent is controlled by hormones secreted by :
a. Leydig cells
b. Sertoli cells
c. primordial germ celss
d. genital chord
1.
Descent is controlled by two ligaments: the suspensory and the gubernaculum. what happens during descent:
- Both the suspensory and the gubernaculum elongate
- The suspensory elongates and the gubernaculum does not
- The gubernaculum elongates and the suspensory does not
2.
Regarding the timetable for descent, which is true
- The testes have migrated over the pubic bone by weeks 22-26
- The testes have migrated over the pubic bone by weeks 24-26
- The testes have migrated over the pubic bone by weeks 25-28
- The testes have migrated over the pubic bone by weeks 25-32
- The testes have migrated into the scrotum by weeks 35-40
- The testes have migrated into the scrotum by weeks 35-38
- The testes have migrated into the scrotum by weeks 32-36
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