Reproduction Endocrinology

Question 1

What organ in the brain is responsible for production of GnRH?

Answer 1

hypothalamus

Question 2

What cells are responsible for the production of testosterone?

Answer 2

Leydig Cells

• Luteinizing hormone (LH) acts on the Leydig cells within the testes. They contain membrane-bound receptors for LH. When LH binds to their receptors, Leydig cells produce progesterone, most of which is converted to testosterone.*
• Leydig cells are analagous to theca interna cells in females*

Question 3

T/F: In the male, FSH acts on the Sertoli cells to secrete progesterone

Answer 3

False

In the male, FSH acts on the Sertoli cells to secrete estradiol

Question 4

T/F: In the male, LH acts on the Leydig cells to secrete testosterone

Answer 4

True

Question 5

Inhibin is produced by Sertoli cells and acts to suppress __________

Answer 5

FSH

Question 6

The third or final phase of spermatogenesis is the __________ phase

Answer 6

differentiation phase

No further cell divisions take place during this phase.

Question 7

__________ is the primary reproductive hormone released from the posterior pituitary

Answer 7

Oxytocin

Question 8

The primary releasing hormone of reproduction is:

Answer 8

GnRH

• Gonadotropin releasing hormone, produced by the hypothalamus.*
• Releases gonadotropins (FSH, LH, prolactin) from anterior pituitary*

Question 9

Luteinizing hormone (LH) is responsible for causing ovulation and stimulating the corpus luteum (CL) to produce __________

Answer 9

progesterone

LH causes testosterone production in the male

Question 10

The hypothalamopituitary gonadal axis regulates reproduction primarily based upon a __________

Answer 10

positive and negative feedback system

Question 11

The major luteolytic hormone is:

Answer 11

prostaglandin F_2a (PGF_2a)

Causes the corpus luteum to stop functioning

Question 12

What is the main function of prostaglandin E₂ (PGE₂)?

Answer 12

relaxation of the cervix

basically, just don’t confuse this with PGF_2a, which essentially does the opposite thing

Question 13

__________ hormones bind to plasma membrane-bound receptors.

__________ hormones travel freely through plasma membrane into cytoplasm and bind directly to specific nuclear receptors

Answer 13

Protein hormones bind to plasma membrane-bound receptors.

Steroid hormones travel freely through plasma membrane into cytoplasm and bind directly to specific nuclear receptors

Question 14

What is the primary action of follicle stimulating hormone (FSH) in females?

Answer 14

follicular development and estradiol synthesis

Question 15

When released from the uterus this hormone causes luteolysis:

Answer 15

PGF_2a

Question 16

Steroids are metabolized in the __________

Answer 16

liver

High producing dairy cows = larger livers

Question 17

The paramesonephric tubules are most fused in which animal?

• Dog
• Sow
• Horse
• Cow

Answer 17

Horse

biggest uterine body