Ch. 28 - Male Reproductive System

Question 1

C/C cremaster and dartos muscles of the scrotum

Answer 1

C - sk that moves testes close to body

D - sm that decreases SA of scrotum

Question 2

What do the testes contain?

Answer 2

each lobule is filled with 2-3 seminiferous tubules where spermatogenesis occurs

Question 3

What are the 2 cell types in seminiferous tubules?

Answer 3

• spermatogenic cells (form sperm)

- sustentacular (support)

Question 4

What cells are located in between seminiferous tubules? What is their function?

Answer 4

interstitial cells; secrete testosterone

Question 5

What are the stem cells in seminiferous tubules?

Answer 5

spermatogonia (2n) located against basement membrane; develop into sperm toward lumen

Question 6

What is the function sustentacular cells?

Answer 6

joined by tight-junctions to form blood-testis barrier

Question 7

Describe the differentiation of spermatogonia

Answer 7

spermatogonia (2n) 
primary spermatocytes (2n)
secondary spermatocytes (n, after meiosis I)
spermatids (n, after meiosis II)
spermatozoa (n)

Question 8

What is the function of the acrosome on a sperm head?

Answer 8

has enzymes to help penetrate and fertilize a secondary oocyte

Question 9

Describe the hormonal control of spermatogenesis

Answer 9

during puberty:

hypothalamus releases GnRH
ant pituitary secretes LH and FSH
- LH: stimulates testosterone secretion
- FSH: stimulates spermatogenesis

Question 10

What is the pathway of sperm through ducts?

Answer 10

seminferous tubules
ductus epididymis
ductus deferens

Question 11

What is the function of the epididymis?

Answer 11

site of sperm maturation; can be stored here or ejaculated

Question 12

What is the function of the ductus deferens?

Answer 12

stores sperm and propels them from epididymis toward prostatic urethra during ejaculation

Question 13

What is a vasectomy?

Answer 13

• incision to remove a portion of the vas deferens

- sperm still produced but cannot reach exterior; degenerate and removed by phagocytosis

Question 14

What forms the ejaculatory duct?

Answer 14

union from seminal vesicle and ampulla of ductus deferens

- terminate in prostatic urethra

Question 15

What are the 3 sections of the urethra?

Answer 15

• prostatic
• intermediate (through deep muscles of perineum)
• spongy (through penis)

Question 16

Why does prostate enlargement lead to difficulty urinating?

Answer 16

prostate wraps around and compresses urethra

Question 17

What are the 3 accessory sex glands?

Answer 17

seminal vesicles, prostate, bulbourethral glands

• secrete most of liquid portion of semen!

Question 18

What is the function of seminal vesicles?

Answer 18

secrete an alkaline viscous fluid that contains fructose, prostaglandins, and clotting proteins

Question 19

What is significant of the alkaline pH of the fluid produced by the sem vesicles?

Answer 19

neutralize acid in male urethra and in female repro tract for sperm viability

Question 20

What is the function of the prostate?

Answer 20

secretes milky, acidic fluid into prostatic urethra containing citric acid and proteolytic enzymes

Question 21

What is part of the acidic fluid produced by the prostate?

Answer 21

citric acid - used by sperm for ATP production

proteolytic enzymes - liquefy coagulated semen, act as antibacterial agents

Question 22

What is the function of bulbourethral glands?

Answer 22

secrete an alkaline fluid into urethra to protect sperm by neutralizing acids from urine
- also secrete mucus as lubricant

Question 23

What is semen?

Answer 23

mixture of sperm and seminal fluid

• secretions from seminiferous tubules, seminal vesicles, prostate, bulbourethral glands
• slightly alkaline (pH 7.2-7.7)

Question 24

What is the penis composed of?

Answer 24

• body, root, glans penis
• 3 masses of erectile tissue
• 2 corpus cavernosa
• corpus spongiosum

Question 25

What is the function of erectile tissue?

Answer 25

• spongy structures composed of blood sinuses lined by endothelial cells
• surrounded by sm muscle and elastic CT
• fill with blood during erection

Question 26

What is the function of the corpus cavernosa?

Answer 26

dorsolateral; maintain erection

Question 27

What is the function of the corpus spongiosum?

Answer 27

contain spongy urethra; keep it open during ejaculation

Question 28

Describe how a parasympathetic reflex causes an erection

Answer 28

• sexual stimulation dilates the arteries supplying penis

- expansion of blood sinuses compress veins, trapping blood in penis to maintain erection

Question 29

Describe how ejaculation is a sympathetic reflex

Answer 29

• peristalsis in epididymis, ductus deferens, seminal vesicles, ejaculatory ducts, and prostate propel semen into spongy urethra
• urination is prevented

Question 30

What happens after ejaculation?

Answer 30

• arterioles supplying erectile tissue constrict
• smooth muscles within erectile tissue contract
• blood sinuses become smaller, reliving pressure from veins
• blood drains