Gross Male Reproductive

Question 1

What is the function of the epididymis? Its tail becomes the ______________

Answer 1

maturation and storage of sperm

tail becomes the ductus (vas) deferens

Question 2

What two mechanisms are important in maintaining a constant temperature for sperm production?

Answer 2

1. evaporation (from surface of scrotum)

2. countercurrent heat exchange

Question 3

What neurovascular differences exist between the anterior and posterior scrotum?

Answer 3

anterior: EXTERNAL pudendal artery and vein - ilioinguinal nerve
posterior: scrotal branches of the INTERNAL pudendal artery and vein - posterior pudendal nerve

Question 4

Lymphatics in the superficial fascia of the scrotal sac and penis drain primarily into the ______________ nodes. However, the structures deep to Buck’s fascia of the penis and structures within the testis usually drain into the ______________ and ______________ nodes.

Answer 4

superficial inguinal nodes

internal iliac nodes and inguinal nodes

Question 5

What is the tunica albuginea? Describe its relationship to the mediastinum and lobes of the testis.

Answer 5

thick covering of connective tissue

thickened and specialized for the mediastinum
fibrous septae that penetrate and subdivide it into lobules

Question 6

All the arteries that lie deep to Buck’s fascia on the penis come from branches of the ______________ artery, which takes its origin from the ______________ artery.

Answer 6

internal pudendal artery

origin from anterior division of the internal iliac artery

Question 7

Describe the origin, course and functions of the deep dorsal vein of the penis.

Answer 7

venous return from the corpora cavernosa
course: beneath arcuate ligament surrounding pubic symphysis and above the transverse ligament
drains in the prostatic venous plexus and vesicle plexus (ending in the iliac veins)

Question 8

During a rectal exam in the male, it is possible to palpate the following structures:

Answer 8

inferoposterior lobule (inferior to the urethra)
prostate feels "hard" on exam in the case of prostate cancer

Question 9

Structures present on the posterior wall of the prostatic urethra include:

Answer 9

urethral crest (elevated ridge), colliculus seminalis, utricle where the ejaculatory ducts terminate on either side and prostatic sinuses where the tubuloalveolar glands drain

Question 10

The ducts draining the prostate terminate in the ______________, a feature of the prostatic urethra.

Answer 10

utricle (in the middle of the colliculus seminalis)

Question 11

List the descriptive subdivisions of the male urethra. Give origins and terminations.

Answer 11

• prostatic urethra: bladder neck to membranous urethra
• membranous urethra: interconnects prostatic and spongy urethra (apex of the prostate through the perineal membrane) - bulbourethral glands on either side
• penile/spongy urethra: starts below deep perineal space to the end of penis

Question 12

What is a vasectomy?

Answer 12

vas deferens is isolated and ligated through small incision at the superior aspect of the scrotal sac

Question 13

What is produced in the seminal vesicles? The prostate? What is the importance of these secretory products?

Answer 13

seminal vesicles: fluid 70% - containing fructose, prostaglandins, ascorbid acid, simple sugars, amino acids - nutrients for sperm
prostate: fluid 30% - contains citric acid, acid phosphatase, zinc - stimulate fertility, enhance sperm motility, adjust pH of the urethra

Question 14

Explain the consequences of enlargement of the middle lobule of the prostate.

Answer 14

encroaches directly on the uvula of the bladder and hampers urination
bacteria may accumulate due to stagnant urine trapped in the bladd = UTI

Question 15

What is a crus? What does it become? What muscle is it associated with in the superficial perineal space? What is the nerve supply of that muscle?

Answer 15

• tendon-like structures that attach each corpus cavernosum of the penis to an ischiopubic ramus
• origin of the true erectile tissue
• muscle: ischiocavernosus muscles
• nerve supply: dorsal nerves (terminal branches of the pudendal nerve)

Question 16

What is the difference between corpus spongiosum and corpus cavernosum?

Answer 16

spongiosum: surrounds the urethra
cavernosum: 2 - true erectile tissue (large venous sinuses)

Question 17

What muscles make up the pelvic diaphragm?

Answer 17

levator ani and coccygeus muscles

Question 18

What may happen if the pelvic floor is weak or incompetent?

Answer 18

rectal incontinence

Question 19

With which nerves would the visceral afferent fibers travel that are responsible for sensing fullness of the bladder? Of the rectum?

Answer 19

Bladder: pelvic splanchnic nerves
rectum: also pelvic splanchnic

Question 20

What role do pelvic splanchnic nerves play in urination?

Answer 20

contraction of the smooth muscle of the bladder

Question 21

What muscles allow us to retain urine in the bladder? Feces in the rectum?

Answer 21

bladder: pubococcygeous muscle, sphincters
rectum: puborectalis muscle, sphincters

Question 22

What nerve fibers are responsible for vasodilation in erectile tissue? What afferent signals elicit this response? What other activity occurring concomitantly is initiated by these same afferent signals?

Answer 22

vasodilation: efferent signals pelvic splanchnic nerves
afferent: sympathetics from splanchnic
other activity: stimulation of secretory activity in bulbourethral glands

Question 23

What is the role of the lumbar splanchnic nerves in ejaculation?

Answer 23

continues afferent input results in activation of the sympathetic fibers stimulates contratcion of smooth musculature of the ducts of the epididymis, vas deferens, prostate, and seminal vesicles - releasing contents into the prostatic urethra

Question 24

What is the role of the pudendal nerve in ejaculation?

Answer 24

to cause rhythmic contractions of the bulbospongiosus and ischiocavernosus muscles