4. Embryogenesis of the Pituitary and Reproductive System

Question 1

What are the three germ layers that form the inner cell mass of the blastocyst?

Answer 1

• Endoderm
• Mesoderm
• Ectoderm

Question 2

Shrinkage of the gubernaculum within the scrotum

Answer 2

inguinal-scrotal phase

Question 3

Network of tubules that connect the seminiferous tubules with the efferent ducts

Answer 3

rete tubules

Question 4

Network of tubules that connect the seminiferous tubules with the efferent ducts

Answer 4

cryptorchidism

Question 5

A female born twin to a male will demonstrate varying degrees of masculinization. This is known to occur in what species?

Answer 5

bovine

Question 6

During migration in fetal development, primordial germ cells increase exponentially in number by undergoing _____ cellular division.

Answer 6

mitotic

Question 7

The dual embryonic origin of the pituitary gland allows each lobe to produce and secrete different products. The _______ consists of specialized glandular cells and secrete hormones such as _____. In contrast, the _______ develops from neuronal tissue and secretes hormones such as _______.

Answer 7

adenohypophysis; FSH

neurohypophysis; oxytocin

Question 8

what parts of the reproductive tract develop from the ectoderm

Answer 8

penis, vestibule, clitoris

Question 9

The ___ chromosome contains a gene which codes for a specific protein that triggers the development of the male reproductive system. Sertoli cells secrete ______ which in the company of _____secreted by the Leydig cells, promote the degeneration of the ______.

Answer 9

Y
Anti‑mullerian Hormone
testosterone
paramesonephric ducts

Question 10

what do sertoli cells secrete?

Answer 10

anti-mullerian hormone

Question 11

Which germ layer does the reproductive system primarily develop from?

Answer 11

mesoderm

Question 12

what is another term for the anterior lobe of the pituitary

Answer 12

adenohypophysis

Question 13

what is another term for the posterior lobe of the pituitary

Answer 13

neurohypophysis

Question 14

which lobe of the pituitary gland develops from the infundibulum

Answer 14

posterior

Question 15

which lobe of the pituitary gland develops from tissue in the roof of the mouth/Rathke’s pouch?

Answer 15

anterior

Question 16

what is the bony cavity that protects the pituitary gland?

Answer 16

sell turcica

Question 17

what does hypophysis mean?

Answer 17

pituitary

Question 18

what allows for the two lobes of the pituitary to have entirely different functions?

Answer 18

dual embryonic origins

Question 19

_____ content establishes the sex of the embryo

Answer 19

chromosomal

Question 20

where do the primordial germ cells originate from?

Answer 20

base of hindgut

Question 21

where do primordial germ cells end up after migration?

Answer 21

genital ridge

Question 22

what do the primordial germ cells form after migration?

Answer 22

bipotential gonad

Question 23

a _____ gonad is capable of differentiating along two different pathways

Answer 23

bipotential

Question 24

what happens to primordial germ cells that do not make it to the genital ridge during migration?

Answer 24

they degenerate

Question 25

what stimulated primitive sex cord formation?

Answer 25

primordial germ cells arrive in genital ridge and stimulate local connective tissue to proliferate

Question 26

the reproductive system develops in close proximity to and at the same time as the _____ system

Answer 26

renal

Question 27

female reproductive ducts are called (2 names)

Answer 27

paramesonephric ducts
Mullerian ducts

Question 28

male reproductive ducts are called (2 names)

Answer 28

mesonephric ducts
wolffian ducts

Question 29

where is the SRY gene located?

Answer 29

Y chromosome

Question 30

what protein secretion stimulates development of the male reproductive system?

Answer 30

SRY protein

Question 31

Secretion of ______ by the sertoli cells causes differentiation of _____ cells which secrete ______

Answer 31

anti mullerian hormone
leydig
testosterone

Question 32

which two hormones cause the degeneration of the mullerian duct system and the development of the male reproductive system?

Answer 32

anti-mullerian hormone (secreted by sertoli cells) and testosterone (secreted by Leydig cells)

Question 33

what does the rete testis connect to the seminferous tubules during testicular development?

Answer 33

efferent ducts

Question 34

what are the 3 phases of testicular descent?

Answer 34

• Growth & elongation of the fetal body away from the testes (trans-abdominal)
• Rapid growth of the extra-abdominal gubernaculum (trans-abdominal)
• Shrinkage of the gubernaculum within the scrotum (inguinal-scrotal)

Question 35

why are crytorchid animals capable of producing testosterone?

Answer 35

cryptorchid testes are sterile but testoterone production is not heat sensitive like spermatogenesis

Question 36

what causes inguinal herniation?

Answer 36

When a portion of the intestine passes through the inguinal canal into the vaginal cavity and scrotum

Question 37

in which species is inguinal herniation common?

Answer 37

swine

Question 38

what happens to the sex cords during female sexual differentiation?

Answer 38

differentiate into primitive follicular cells and the genital ridge becomes an ovary

Question 39

What parts of the female reproductive system develop from the Mullerian duct system?

Answer 39

Oviducts, Uterus, Cervix, and Cranial vagina

Question 40

the degree of fusion in the ________ ducts determines the type of uterus

Answer 40

mullerian

Question 41

what is a freemartin

Answer 41

a sterile heifer born twin to a bull

Question 42

why does freemartinism happen in cattle?

Answer 42

extraembryonic membranes fuse to form a common chorion, leading to transfer of testosterone and primordial germ cells via a common blood supply