#36

Question 1

What are the testes mainly made out of?

Answer 1

seminiferous tubules

Question 2

what cells secrete testosterone?

Answer 2

leydig cells

Question 3

How is testosterone secreted during fetal development?

Answer 3

placental hCG acts on leydig cells to secrete testosterone leading to male sex differentiation

Question 4

How is testosterone secretion controlled at puberty?

Answer 4

GnRH from hypothalamus acts on anterior pituitary to secrete LH to act on leydig cells to secrete testosterone. Leads to pubertal growth and maturation

Question 5

a gymnast is taking high levels of testosterone. After a few months, what would his levels of GnRH, LH, and FSH be?

Answer 5

all low. The testosterone is causing a negative feedback on all of them

Question 6

What are the side effects of steroids in men?

Answer 6

shrinkeage, enlarged prostate, headached, aching joints, aggression, etc

Question 7

problems with testosterone in women?

Answer 7

reduced breast size, enlarged clitoris, increased body and facial hair, deepened voice, menstrual problems

Question 8

Where are sperm developed?

Answer 8

sertoli cells, which combine to make the seminiferous tubules

Question 9

control of spermatogenisis

Answer 9

testosterone causes sertoli cells to undergo spermatogenisis, and after they do they secrete INHIBIN. inhibin is hegative feedback on FSH secretion.

Question 10

blood testes barrier

Answer 10

sertoli cells contain tight junctions and provide a protective barrier against potential contamination. Disruption causes spermocyte death and sterility

Question 11

What substance disrupts the blood testes barrier?

Answer 11

cadmium. Mostly comes from smoking.

Question 12

DBCP pesticide- what does it do?

Answer 12

causes male infertility without leydig or sertoli cell destruction

Question 13

2BP what does it do?

Answer 13

cleaning solvent that may impact fertility in males

Question 14

nervous system in penis at rest

Answer 14

sympathetic, NE is released at arterioles and causes continual vasoconstriction

Question 15

nervous system during erection

Answer 15

decreases SNS, increased PNS input to arterioles. Nitric oxide release triggers vasodilation, filling of vascular compartments with blood

Question 16

Molecular pathway for erection

Answer 16

nitric oxide stimulates guanylyl cyclase which converts GTP to cGMP causing smooth muscles to relax and increasing bloodflow

Question 17

how does viagra work?

Answer 17

Inhibits PDE-5, which breaks down cGMP. Keeps cGMP levels high so the smooth muscles stay relaxed

Question 18

eaculation-emission stage

Answer 18

continued stimulation results in spinal reflex activation of sympathetic nerves that innervate prostate, seminal vesicles and reproductive ducts leading to the delivery of semen to the urethra

Question 19

expulsion phase

Answer 19

semen in urethra triggers sympathetic reflex, a series of skeletal muscle contractions