Despite how localised an erection appears, it’s actually the result of a complex process that involves the endocrine, muscular, vascular and neurological systems. the penis gets stiff in a series of distinct steps.
The first reaction, arousal, occurs when the nerves are stimulated and microscopic blood vessels in the organ begin to dilate. This can be triggered by something your guy sees, hears, smells, feels or imagines. the link is so intimate and immediate, it’s as if the penis has sense organs of its own.
When the brain decides it’s time for the penis to rise to the occasion, it shoots signals down to the lumbar area of the spinal cord. From there, the messages hightail it along a network of nerves to the penis. When they arrive, the tiny muscles within the penile arteries relax and blood rushes in at six to eight times the normal rate. Your guy’smember then becomes engorged–making it bigger, firmer and more erect.
And when everything’s in working order, the penis stays hard long enough to accomplish its goal. that’s because a valve-likemechanism within his unit prevents blood from flowing back out too soon. Once your guy ejaculates – or if his arousal is interrupted for some other reason – the penis quickly becomes flaccid again.