Answer:
An erection is a hardening of the penis that occurs when sponge-like tissue inside the penis fills up with blood. Usually, an erection causes the penis to enlarge and stand away from the body.
What causes erection?
When men become sexually aroused, hormones, muscles, nerves, and blood vessels all work with one another to create an erection. Nerve signals, sent from the brain to the penis, stimulate muscles to relax. This, in turn, allows blood to flow to the tissue in the penis.
