Male Repro 2

Question 1

What is the difference between between a musculovascular and fibroelastic penises?

Answer 1

musculovascular penises enlarge in length and diamater during tumescene whereas fibroelastic penises are sigmoidal shaped that extend only in length during tumescence

Question 2

What is the urethral process?

Answer 2

an extension of the urethra that extends beyond the length of the penis in the ram and the buck

Question 3

What is the function of the urethral process?

Answer 3

it is possibly a mechanism to propel sperm deeper into the female reproductive tract

Question 4

Why can the urethral process be problematic?

Answer 4

because it can get stones trapped in it

Question 5

What is corpus cavernosum?

Answer 5

erectile tissue of the penis

Question 6

What is the corpus spongiosum?

Answer 6

spongy area that surrounds the urethra and prevents occlusion of the urethra during tumescence

Question 7

What is nitric oxides role in tumescence?

Answer 7

it causes dilation of the helicine artery which allows blood to move through the loosened interendothelial junctions

Question 8

What is nitric oxide released from in tumescence?

Answer 8

it is released by non-adrenergic/non-cholinergic neurons from the parasympathetic system

Question 9

What biochemical basis allows for detumescence to occur?

Answer 9

phosphodiesterase 5 recycles cGMP to GMP thus halting tumescence by returning the vascular smooth muscle to its contracted state

Question 10

What is the vascular basis of detumescence?

Answer 10

once the vascular smooth muscle ccontracts, blood from the helicine artery leaves the corpus cavernosum and the penis drains

Question 11

What autonomic system is tumescence driven by and how does it work?

Answer 11

the parasympathetic division involving the release of norepinephrine that relaxes the vascular smooth muscle of the helicine artery in the penis

Question 12

What autonomic system is ejaculation driven by and how does it work?

Answer 12

the sympathetic system that promotes the release of mucus and the coordinated contraction of the epididymis, vas deferens, and urethra

Question 13

What autonomic system is demutescence run by?

Answer 13

the sympathetic system

Question 14

What hypothalamic peptide is the central regulator of male reproductive physiology?

Answer 14

GnRH

Question 15

What are the two anterior pituitary hormones that regulate male reproductive physiology?

Answer 15

LH and FSH

Question 16

What is the function of LH in male reproductive physiology?

Answer 16

it synthesizes testosterone in the leydig cells

Question 17

What is the function of FSH in male reproductive physiology?

Answer 17

it stimulates spermatogenesis in the sertoli cells by promoting the elevation of the spermatocytes towards the lumen of the seminiferous tubules

Question 18

What is the negative regulator of the male reproductive physiologic hormones?

Answer 18

inhibin

Question 19

What is the role of inhibin in male reproductive physiology?

Answer 19

it activates its receptor and promotes the synthesis of proteins that trap FSH in the anterior pituitary cells or GnRH in the hypothalamus

Question 20

What does inhibin come from?

Answer 20

sertoli cells

Question 21

Why does testosterone interact with an intracellular receptor while other hormones interact with receptors that extend outside of the cell?

Answer 21

because testosterone is lipid-soluble so it can cross biological membranes and interact with its intracellular receptor

Question 22

What is the os penis?

Answer 22

a bone in the penis in the dog, cat, and non-human primates that aid in maintaining tumescence

Question 23

What is the bulbus glandis?

Answer 23

a portion of the penis in the dog that enlarges during coitus which helps maintain the ineraction with the female

Question 24

Why is cancer a side effect of anabolic steroids that mimic testosterone?

Answer 24

because it upregulates specific gene expression in genes that encode for proteins that promote hyperplasia