10 things you should know about penises and scrotums

There’s much more to it than meets the eye

Written by Abigail Swoap

Penises have a reputation for being “easy to figure out,” but there’s a lot happening down there that’s worth knowing about. Read on for our top ten facts you need to know about penises and scrotums.

Penises typically stop growing at the end of puberty

For boys and young men, puberty is usually drawn out over several years, so the exact end of puberty can be hard to pinpoint. In the United States, puberty is usually over with by the age of 18. 

It’s hotly debated (but not confirmed) if there are differences in sensitivity between circumcised and uncircumcised penises.
The foreskin is covering a very sensitive part of the penis: the glans. When the foreskin is removed, there is speculation that there are nerve endings removed as well. However, no direct studies have narrowed the precise amount of nerve endings that might be removed during circumcision. There are studies that have found that the uncircumcised penis is more sexually sensitive than the circumcised one. 

One study found that penile temperature and sexual response was stronger for circumcised penises, but every other measure of sensitivity and arousal did not differ based on circumcision status. Another systematic review of studies examining sensitivity in the penis based on circumcision status found that loss of the foreskin does not appear to have any adverse affect on sexual pleasure.

Whether you're a “grower” or a “shower” depends on the tissues in your penis 

You may have heard that vulvas are like snowflakes. Well, so are penises! Variety in penis appearance is due to the diverse array of tissues that make them up. The erectile tissue in the penis consists of elastic fibers, collagen, arteries, veins and smooth muscle tissue. The way these all work together determines whether or not one is a grower or a shower. These muscles and tissues and elastics change with age, too, so someone might be a grower at one point and gradually become a shower. 

Also, being a shower might be slightly more common than being a grower. According to one study from 2018, about 26% of penis-havers are growers and 74% are showers.

Blue balls happen when the epididymis experiences hypertension

A quick anatomical refresher: the epididymis is the tube that connects the testes to the vas deferens and transports sperm. It’s also involved in the mechanisms that contribute to increased blood flow to the penis during arousal. In this context, “hypertension” refers to increased blood flow to the penis that is sustained for a longer period of time without the release of orgasm. Sometimes, this extended period of arousal can cause pain and discomfort. 

It’s totally normal for one ball to hang slightly lower than the other

The reason for this is most likely evolutionary and geared towards protecting the scrotum. When one ball hangs lower than the other, they don’t knock against each other and can be housed more easily within the scrotum. Research has also attributed it to more well-developed and greater flexion of muscles on one side of the lower abdomen relative to the other side and/or the different length and angle of the blood vessels that serve the testicles.

Part of the reason it hurts to get hit in the scrotum is that it’s connected to nerves throughout the whole body 

The scrotum nerves are connected to the same nerves as the abdomen, spine and anus (which includes the perineal and pudendal nerves and the spermatic plexus). When you get hit in the scrotum, the pain travels along the route of all those nerves, making the pain feel super intense throughout the body.

Looking for a foolproof penis hygiene method? Water and a little soap are all you need

In the shower, make sure you wash the scrotum and penis with warm water. People with uncircumcised penises should pull the foreskin back and gently wash underneath to prevent the build-up of smegma. You should only need warm water, but it's ok to use soap. Just not too much! Overdoing it with the suds can cause irritation and rid your body of its natural moisture. 

The glans of the penis is homologous to the clitoris

According to Coral contributor Dr. Emily Nagoski, we all start with “the same parts, organized in different ways.” In fact, everyone begins in the womb with a “combined clitoral-penile tubercule.” Once week eight of gestation rolls around, for people with Y chromosomes, testosterone starts to kick in and a structure called the glans (the head of the penis) starts to form. 

Although the penis is external and the clitoris is internal, their structures are remarkably similar. For example, the head of the penis is homologous to the glans clitoris (its visible head where the inner labia meet). The clitoral hood and foreskin are also related in a similar way.

Both penises and clitorises can become erect 

The clitoris and penis both contain erectile tissue, which is highly sensitive and capable of hardening when it becomes engorged with blood. 

Penises and scrotums are just as sensitive as vulvas, but in different ways

It’s often said that vulvas are more sensitive than penises because they contain more sensory nerve endings than the glans (or head) of the penis. 

But it really depends on what you mean by “sensitive.” The scrotum is more sensitive to pain, especially because it isn’t protected at all. Those glands just have a thin layer of skin protecting them, so when they are hit, it hurts more than getting hit in other spots. The vulva has the mons pubic protecting it, so it’s less sensitive to pain. 

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