1029 - Male Sexual Function

Question 1

How does an erection take place?

Answer 1

Psychogenic stimulation fires thoracolumbar erection centre (T11-L2), which leads to vasodilation, increased blood flow through penis (parasympathetic). This swells corpus cavernosa, blocking venous return, leading to erection.
Tactile stimulation fires sacral erection centre (S2-S4), leading to erect penis reflex arc.
Ongoing stimulation is required to keep erection up.

Question 2

What are the phases of erection?

Answer 2

Tumescence - increased blood flow (5-10x normal) - large but soft.
Rigidity - contraction of ischiocavernosus muscle (reflex) squeezes crura and raises cavernosal pressure, arterial flow ceases.
Detumescence - SY driven smooth muscle contraction, slow emptying until venous outflow effective.

Question 3

What are the types of erections?

Answer 3

Psychogenic - mental focus on stimulus, decrease with age
Reflex - direct stimulation
Nocturnal penile tumescence

Question 4

What changes occur with male sexual arousal?

Answer 4

Rise in pulse, RR, BP
Flushed and sensitive skin
Increased muscular tension
Engorgement of penis and testes
Contraction and elevation of scrotum
Cowper’s gland secretion.

Question 5

What are the effects of aging on male sexual arousal?

Answer 5

Erections - longer to get, difficult to sustain, need more direct stimulation, detumescence quicker.
Plateau phase prolonged
Less intense orgasm, lower ejaculatory volume, and longer refractory period.