When most people read the word "erection," they probably think of a penis, specifically, a penis that is hard. Penile erections are without a doubt the most talked-about erections in the body, and below you can learn just how a male erection works. However, it's worth knowing that a penis isn't the only part of the body that gets erect.
Any part of the body that has erectile tissue can become erect. Erectile tissue, as it sounds, is tissue that can become erect or get hard, usually because blood flows into the tissue and stays there for a period of time, keeping the tissue, and subsequently the body part, erect. Other body parts with erectile tissue include the clitoris, the urethral sponge, and the ears.
In most societies, there is such a focus on the penis itself that most of us (including all of us who have them) don't realize that getting an erection is really a team effort of body and mind. Getting and maintaining an erection is a complex and fluid event (pardon the pun), more like a symphony than a simple tune. It involves our nerves, blood, hormones, and muscles, and often our thoughts and feelings too.
Few things that happen in the body occur in clear-cut stages, but for ease of explanation we can think of the making of an erection as involving a few stages from beginning to end.
Most erections begin with stimulation. The stimulation may be physical (as in you or someone else touching a part of your body), and it might be stimulation of the penis or of any part of the body. The stimulation may also be mental or psychological, such as when you think sexual thoughts or have sexual feelings. Erections can happen as a result of either. Most men will also get what are called spontaneous or reflex erections, meaning you get an erection even when you aren't being touched or thinking sexual thoughts. But here we're talking about erections that were meant to happen.The stimulation then triggers multiple responses in the body. It may trigger messages from nerve endings, it may trigger chemicals in the brain, or it may be both. In any case, messages from inside the body are sent to parts of the penis (called smooth muscle) with the message that they should relax.
As the smooth muscle relaxes, the arteries that supply blood to the penis open wider, which allows more blood to begin flowing into the penis. As blood flows into the penis, it becomes hard and an erection occurs.
As the penis becomes engorged with blood, the veins that usually direct blood out of the penis are compressed, which prevents the blood that flows in from leaving the penis. The blood stays in the penis, which is what maintains an erection.
Once a man ejaculates, the blood flows out of the penis and the erection goes away. After this, there is a period of time called the refractory period, during which it is difficult for a man to have another erection.
Of course, the above description is very general. The way erections do, and sometimes don't, work in each individual body will depend on many factors. Because erections involve so many bodily systems, and happen as a result of a delicate balance of factors, when men begin having difficulty getting erections, it can be a early sign of something else going on in the body. While occasional difficulty getting erections is completely expected for men of any age, consistent erectile problems are a good reason to get a check-up and talk with your doctor.