How does an erection occur?
An erection is an involuntary reaction in response to sexual stimulation and excitement.
- A man cannot get an erection simply because he wants one.
- Sexual stimulation and excitement cause the brain, nerves, the heart, blood vessels, and hormones to work together to produce a rapid increase in the amount of blood flowing to the penis.
- The blood becomes trapped and held in the two spongy chambers in the shaft of the penis.
- As the chambers rapidly fill with blood, they expand, and the penis becomes firm and elongated.
- The result is an erection.
1) Sexual stimulation and excitement cause the brain, nerves, the heart, blood vessels and hormones to work together to produce a rapid increase in the amount of blood flowing to the penis.
2) The blood becomes trapped and held in the two spongy chambers in the shaft of the penis.
3) As the chambers rapidly fill with blood, they expand, and the penis becomes firm and elongated. The result is an erection.

