Penis, Erection, and Orgasm at A Glance….

What Your Penis Is Built Of….

The penis is the male sexual and reproductive organ. While appreciated as whole, it consists of a few different parts, including the head (glans), and the shaft or body. The penile body consists of three spongy tissue cylinders containing many small blood vessels. Besides blood vessels, the entire penile is rich on many nerve endings that make it sensitive to touch, pressure, and temperature.
The head of the penis (glans) has compared to the rest of it the most and highest concentration on nerves and thus is very sensitive to touch.
Two further areas highly sensitive  to touch are the rim that separates the glans from the shaft of the penis (coronal ridge), and the small triangular region on the underside of the penis where the frenulum, a thin strip of skin, attaches to the glans.

What Happens During Arousal…

When a man gets excited, blood fills the vessels of the spongy body causing them to become engorged  and the penis to swell up. It becomes firm and grows in size; erection is basically the transition from the soft (flaccid) state of the penis to the hard and erect one. The erect penis can be used for intercourse and sexual encounter.
 

And Then Come the Orgasm…

When achieving the climax, an orgasm in men is usually accompanied with the exertion of ejaculate from the tip of the penis. The ejaculate consists of seminal fluid and sperm. After ejaculation, the male penis usually relaxes and the blood vessels allow the blood to exit the spongy bodies returning the penis to a flaccid state.