Erectile Dysfunction

Question 1

What part of the hypothalamus gives ability to recognize sexual partner (integrates hormonal and sensory cues)?

Answer 1

Medial preoptic area (MPOA)

Question 2

What role does the medial preoptic area of the hypothalamus have in erection?

Answer 2

Gives ability to recognize sexual partner (integrates hormonal and sensory cues)

Question 3

What part of the hypothalamus facilitates penile erection?

Answer 3

Paraventricular nucleus (PVN)

Question 4

What role does the paraventricular nucleus of the hypothalamus have in erection?

Answer 4

Facilitates penile erection

Question 5

What part of the brainstem inhibits penile erection?

Answer 5

Paragigantocellular nucleus (PGN)

Question 6

What role does the paragigantocellular nucleus of the brainstem have in erection?

Answer 6

Inhibits penile erection

Question 7

Explain innervation to penis during sex/erection

Answer 7

autonomic
- sympathetic stimulates emission
- parasympathetic stimulates erection
both merge to form the cavernous plexus which innervates penis itself

somatic
- pudendal nerve

Question 8

Seminal emission is what type of an event innervated by which nerve(s)?

Answer 8

adrenergic event stimulated by T10-L2

Question 9

Projectile ejaculation is what type of an event innervated by which nerve(s)?

Answer 9

skeletal muscle event stimulated by pudendal nerve

Question 10

EJACULATION IS SEPARATE FROM PENILE ERECTION

Answer 10

FACT

Question 11

What is the role of nitric oxide in erection?

Answer 11

sexual stimulation leads to lease of NO by cavernous nerves –> enters smooth muscle cells and binds to guanylyl cyclase which converts CTP to cGMP which results in opening of potassium channel and closing of calcium channels –> fall in intracellular calcium –> smooth muscle relaxation and erection

Question 12

What is the role of phosphodiesterase-5 in erection?

Answer 12

Breaks down cGMP and INHIBITS relaxation and erection

drugs that inhibit phosphodiesterase-5 need sexual stimulation to make them work

Question 13

How can erection be invoked by the cAMP system?

Answer 13

PGE-1 binds to cell receptors and activates adenylyl cyclase which converts ATP to cAMP which binds to its own protein kinase which also leads to decreased calcium and smooth muscle relaxation

(drugs that use this pathway do NOT need sexual stimulation to make drugs work)

Question 14

Why does erectile dysfunction often precede CAD?

Answer 14

Arteries in penis are much smaller than arteries everywhere else –> much easier for the arteries to get obstructed before the larger arteries do

Question 15

Be able to differentiate between organic and psychogenic erectile dysfunction

Answer 15

Yep