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Repro and Sexual Health > Embryology > Flashcards

Flashcards in Embryology Deck (40)
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1
Q

What is gastrulation?

A

Formation of trilaminar disc (ectoderm, endoderm, mesoderm)

2
Q

What are the 3 main groups of the mesoderm?

A

Paraxial
Intermediate
Lateral plate

3
Q

How are the definitive endoderm and mesoderm formed?

A

Invaginatino of epiblast cells through primitive streak

4
Q

From what layer is the urogenital system derived?

A

Immediate mesoderm

5
Q

What are the 3 parts to the urinary system?

A

Pronephric
Mesonephric
Metanephric

6
Q

What will the metanephric system form?

A

Kidney

7
Q

In what structure will excretory ducts enter?

A

Cloaca

8
Q

How will primitive germ cells from the yolk sac enter the immediate mesoderm?

A

Via migration through the dorsal mesentery

9
Q

What weeks will the PGCs from the yolk sac migrate to the mesoderm?

A

4-6

10
Q

What is the genital ridge?

A

Coelomic epithelium proliferation

11
Q

What are the primitive sex chords?

A

Proliferating epithelium forming somatic supportive cells enveloping the PGCs

12
Q

What are the 2 genital ducts?

A

Mesonephric (wollfian) = male

Paramesonephric (mullerian) = female

13
Q

Where will the mesonephric and paramesonephric ducts connect?

A

Posterior wall of urogenital sinus

14
Q

At what time will sexual differentiation occur?

A

Week 7

15
Q

What determines the male development?

A

Presence of SRY (short arm of Y chromosome) transcription factor

16
Q

What is the function of SRY?

A

Formation of sertoli cells

17
Q

What will somatic support cells in the male form?

A

Sertoli cells

18
Q

What will the primary sex cords in the male form?

A

Testis which engulf the PGCs

19
Q

What will the rete testis connect?

A

Mesonephric tubules to testis cords

20
Q

What lies between the coelomic epithelium and the testis cords?

A

Thickened layer of connective tissue; tunica albuginea

21
Q

What will sertoli cells secrete in terms of male development?

A

AMH

Gonadal ridge cells to form leydig cells (testosterone)

22
Q

What will testosterone help develop in the male?

A

Epididymis
Vas deferens
Seminal vesicles
External genitalia

23
Q

What will AMH do in male development?

A

Degeneration of paramesonephric duct

24
Q

What will persistent mullerian duct syndrome present as?

A

Uterus, vagina and uterine tubes
Testes in ovarian localtion
Male external genitalia

25
Q

At what level do the testes originate?

A

T10

26
Q

How are the testes pulled through the abdominal cavity?

A

Fibrous attachment to the gubernaculum

27
Q

What is undescended testes called?

A

Cryptorchidism

28
Q

When do the male accessory glands develop?

A

Week 10

29
Q

What are the male accessory glands?

A
Prostate endoderm invagination)
Bulbourethral glands
Seminal vesicle (mesonephric duct)
30
Q

What will germ cells differentiate into?

A

Oogonia and then to primary oocytes

31
Q

What will somatic support cells in females differentiate into?

A

Granulosa cells

Surround primary oocyte

32
Q

What will the female gonad form?

A

Primordial follicles and theca cells

33
Q

What will the paramesonephric ducts in females form?

A

Uterine tubes
Uterus
Superior vagina

34
Q

What are the 3 parts to the paramesonephric duct?

A

Cranial; opens into the coelomic cavity
Horizontal; crosses the mesonephric duct
Caudal; fuses with the paramesonephric duct on opposite side

35
Q

What forms the uterovaginal canal?

A

Fused caudal portion of paramesonephric duct

36
Q

What forms the vaginal lumen and fornices?

A

Vacuolization of paramesonephric portion of vag and sinuvaginal bulbs

37
Q

When will external genitalia be distinguishable?

A

Around week 14

38
Q

How is the spongy urethra formed?

A

Proximal to distal zipping of urethral groove

39
Q

How is the prepuce (foreskin) formed?

A

Circular ingrowth of ectoderm around the periphery of the glans (week 12)

40
Q

What is hypospadias?

A

External urethral opening lies in an abnormal position along the ventral aspect of penis

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