How does penis get elongated when sexually excited? -
The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.
2 of these columns are called the Corpora Cavernosa. They are made up of cavities and erectile tissue that expand and fill with blood to give you an erection. Unlike other mammals, men have no erectile bone and totally rely on engorgement with blood to achieve erection.
To get an erection, your nervous system sends chemical messages to your pelvic area. The smooth muscles inside your penis relax, and the arteries widen. The Corpora Cavernosa act like a sponge and fill up with blood - they hold up to eight times more blood than when your penis is flaccid.
As your penis swells and lengthens, the filled Corpora Cavernosa press against the veins, and this pressure greatly reduces the blood flow from your penis. This keeps your erection hard enough for intercourse.
