Which of the following correctly describes an erection?
A) Smooth muscles of vascular spaces in the penis contract.
B) Parasympathetic impulses constrict arteries leading to the penis.
C) Parasympathetic neurons release nitric oxide, causing dilation of small arteries in the penis.
D) The spongy tissue in the penis fills with air.
E) Skeletal muscle within the penis contracts.

Question

Quizplus · Accepted Answer

Erections involve the relaxation of smooth muscle in the walls of the penile arteries and the corpora cavernosa, leading to increased blood flow into the penis. This process is primarily mediated by parasympathetic nervous system activation, which triggers the release of nitric oxide (NO). NO then causes the dilation of small arteries in the penis, allowing more blood to enter and be trapped in the spongy erectile tissue, leading to an erection.

Which of the Following Correctly Describes an Erection