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Embryology Exam III > Reproductive Development > Flashcards

Flashcards in Reproductive Development Deck (21)
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1

What causes the retention of the mesenephric ducts in the male?

-testosterone produced by the interstial cells of the rete cords

2

What is the origin of the reproductive system? How is the embryo bipotential?

-mesodermal in origin

-gonads arise by proliferation of epithelium along the mesonephric ridge

-embryonic gonad is a neutral gonad which has potential to form testis or ovary

-embryo has both Mullerian and Wolffian ducts

3

How is the bipotential system determined?

-presence or absence of SRY

4

Describe the structure of the indifferent gonad.

-outer cortex and an inner medulla

-within medulla, solid cords of cells develop -> sex cords

-separating the cortex from the medulla is a CT layer called the tunica albuginea
+in the adult gonad, the tunica albuginea will lie on the external surface of the testis but will be internalized in the ovary

5

What do the sex cords give rise to?

-seminiferous tubules containing Sertoli cells and interstitial cells in the event of a male

-anastomosing with the sex cords in the genetic male are the rete cords

-in a female the medulla regresses and the cortex forms the ovary

6

What will the rete cords turn into?

-in the female, the rete cords will degenerate along with the rest of the medulla but some vestigial mesonephric tubules may be retained

-in males, the mesonephric tubules will be retained as part of the closed duct system that conveys sperm to the exterior.
+retained mesonephric tubules are called efferent ductules

7

How does the female system form?

-cortex forms ovary

-rete cords and sex cords will degenerate along with the mesonephric tubules adn ducts

-the Müllerian ducts will give rise to the oviducts, uterus, and a portion of the vagina

-to form the uterus, the Müllerian duct fuses distally

8

What is a bipartite uterus?

-uteri remain unfused and two uteruses remain

9

What is a bicornuate uterus?

-uterus worth two prominent horns

10

What is a simplex uterus?

-single uterus -> human and primate uterus

11

What do the proximal ends of the Müllerian ducts form?

-become expanded as the Ostia of the oviducts

12

When eggs are ovulated they are released from the Graafian follicles and almost immediately enter the Ostia and begin their journey.

:)

13

Where are the ovaries and testes positioned in the abdomen?

-ovaries retain their abdominal position in all vertebrates

-testes retain their abdominal position in poikilotherms, but run into problems of overheating in homeothermic birds and mammals

14

How is testicular overheating prevented in humans?

-testes moved out of abdominal region into the scrotal sacs

15

How do external genitalia start?

-bipotential structures

16

What are the three primordia that give rise to external genitalia?

-genital tubercle

-genital folds

-genital swellings

17

What will the genital tubercle form?

Females: clitoris

Males: glans penis

18

What do the genital folds form?

Females: labia minora

Males: shaft of the penis

19

What will the genital swellings form?

Females: labia majora

Male: scrotum

20

What happens when the primordial germ cells don't migrate into the gonads?

-sterile individual

21

How does SRY influence maleness?

-SRY gene causes the developing Sertoli cells in the sex cords to secrete Mullerian inhibitory factor
+regression of Müllerian ducts