How Does an Erection Occur?
In order to get an erection, several interacting factors are required. First of all, sexual stimulation requires that the blood supply to the penis is sufficient. Compared with resting, it takes about 30 times more blood flowing to the penile erectile tissue in order to get an erection. For this to happen, you need to have healthy vessels which deliver blood efficiently. When the penis is limp, these blood vessels remain closer together.
When an erection occurs, muscles and blood vessels relax via nerve impulses so that inflow may increase. Erectile tissue present in the penis fills and the volume increases. If the outflow of blood is hampered then an erection can accelerate. When the erectile tissue is at maximum, the distended outflow ceases completely and the erection is complete. An erection subsides when the blood inflow decreases in the vessels of the penis which then contract. The pressure then drops in the erectile tissue and the blood flows away.