During sexual intercourse, the penis needs to be very hard and erect so as to promote penetration.  Even after the initial penetration, once the penis becomes limp or say semi-hard, then it is no longer enough to proceed with the sexual intercourse because the male protrusion is no longer strong enough penetrate the vaginal orifice.  This is why an erection is very important during sexual intercourse.

How Does an Erection Occur?

An erection occurs once a man is sexually stimulated, either by though, sight, or touch.  Through this sexual stimulation, the brain sends signals towards the smooth muscle surround the penis and instructing it to relax.  This smooth muscle that surrounds the penis acts the purpose of preventing any erection.  However, once it has been instructed to relax, the cavity that it constricts gets to be filled with blood.  Once this cavity has been engorged in blood, the penis will stand up erect and become firm – perfect for vaginal penetration.  This erection is kept because there is a valve underneath the shaft that prevents blood from rushing out of the cavity.  Once the male has ejaculated or is no longer feeling sexually stimulated, instructions from the brain again is sent telling the smooth muscles lining the penis to return to their normal state.

The length of an erection differs depending on mood, health, and physical or mental exhaustion.  In fact, when foreplay is a bit too long, during the main sexual intercourse itself, the penis can become limp.  This is not due to losing interest, but that the penis has been erect enough for too long.

Wet Dreams and Morning Glory

Erections don’t just occur voluntarily, as a matter of fact, most erections happen involuntarily.  Erections occur throughout life and it can even occur with healthy men that are 90 years of age.  An erection can occur even without any sexual stimulation; such is so that during sleep or during waking up that men can experience having an erection.

Nocturnal erection, the erection that occurs during sleep can occur several times each night.  Many believe that this is important for oxygenating certain parts of the penis.  During nocturnal erections, along with a very stimulating dream, a man can also experience nocturnal emissions or ‘wet dreams’ wherein semen is released without the knowledge of the man having it.  This only becomes obvious as soon as the man wakes feeling sticky spunk on his groin.  Nocturnal erections are also a way of determining whether an erectile dysfunction is physical or psychological in nature.

Morning erections, or aptly called ‘morning glory’ by many, are erections that is a result of waking up during a dream or after a dream.  Morning erections does not mean a man is aroused, although it begins to feel that way due to the satisfying sensation felt because of it, making a man feel kind of aroused.  There are some men who like having ‘morning glories’ because they feel they are already ready for sex upon waking up.