Young children have interesting names for the penis, including ‘tail’ and ‘tap’. This is before they learn more ‘appropriate’ names from adults. However, calling sexual organs by the wrong names is one of the reasons that even as adults, we develop unhealthy sexual attitudes, so it helps to teach our kids – from as young an age as possible – to call a penis a penis (and a vagina a vagina.)
But exactly what is a penis? Is it flesh? Is it bone? Can it break? Well, a penis is an organ made of erectile tissue. Men use it to pee and to have penetrative sex. Erectile tissue has the ability to become firm and rigid, which is how it facilitates sexual intercourse. Keeping his penis erect for extended periods enables a man to last longer in bed.
An erect penis looks a lot like a flesh-covered bone, which is how some sexual nicknames were arrived at. However, the human penis has no bone. (Other animals, including primates, have bones in their penises.) There are two types of erectile tissue that ‘harden’ the penis.
The first – corpuscavernosum – lines the shaft of the penis. There are two of these tissues, and they join at the tip of the penis, forming the head. The second type of tissue is corpus spongiosis. It’s an elastic tissue, and it’s the part of the penis that expels semen and urine. The penis also contains connective tissue.
The endothelium is a layer of cells that is very thin. It lines erectile tissue, allowing stable blood flow that maintains an erection. It runs along the length of the penis, lengthening the distance that blood can travel during erection. This is important because an erect penis ‘elongates’ and sometimes doubles its flaccid size.
The penis becomes erect when the corpus cavernosal is engorged with blood, and this engorgement is triggered by often unconscious signals from the brain. Ideally, the penis stays rigid until intercourse is complete, at which point the man climaxes and releases ejaculate, relaxing his erectile tissue and letting the blood flow back to the rest of his body.
However, when the signals from his brain get interrupted by emotional, medical, or psychological factors, premature ejaculation occurs and blood rushes out of the penis too early, leaving it flaccid and preventing further intercourse. Sometimes, the brain signals are interrupted before blood reaches the penis in the first place, causing erectile dysfunction.
Women’s bodies have erectile tissue as well, in their clitoris. Studies suggest the tip of the clitoris is far more sensitive than the tip of the penis because of its relatively smaller surface area, even though it has the same volume of blood vessels and nerve systems as the penile tip. That said, both the clitoris and the penis are larger than they seem since the bulk of these bodies is inside the pelvic bone. What we see is only a fraction of these body parts.
Erectile tissue isn’t strictly found in the genitals. Our ears and noses contain some erectile tissue as well. However, the nipples don’t have erectile tissue. Instead, they have connective tissues and smooth muscle fibers that contract during breastfeeding, or in response to various stimuli (like cold weather and sexual arousal), making the nipple stiff and erect.