Most men grow up seeing and touching their penises every day. This familiarity may help some men to feel comfortable and confident with their genitals, or as though they know the basic information they need about their bodies. However, there’s more than meets the eye when it comes to male genitals. Learning about your genitals not only helps you to become more familiar with your body and what’s normal (or not), it can also enhance your experience of masturbation or sex with a partner.
Starting with the outside parts, most men have pubic hair though some may choose to remove some or all of it or to groom (trim) it. Men’s pubic hair grows predominantly on the pubic mound but also often grows in smaller amounts on the scrotum and shaft of the penis. Beneath the pubic mound is a small amount of fat and the pubic bone, both of which offer protection to men’s internal reproductive parts.
The penis is a shaft of spongy tissue with three primary purposes: urination, sexual intercourse, and ejaculation. On average, a flaccid (soft) penis is about 3 to 3 ½ inches long. When erect, the penis is about 5 to 6 inches in length (on average) and 4 to 5 inches in circumference (girth). However, there is enormous variation in penis size.
On the outside of the penis, a man may or may not have a foreskin (technically called the prepuce). The foreskin is a double-layer sheath of skin that covers the glans (head) of the penis, ending in the frenar band, a ring of skin that, in most men, slides back over the glans when the penis becomes erect. (Men who have difficulty or pain retracting their foreskin may find it helpful to speak with a healthcare provider about this). Male circumcision involves removal of the foreskin.
The glans of the penis may look a bit like the cap of a mushroom; it is an area of skin that is often very sensitive to touch. It has a few notable parts:
- the meatus, on the tip of the penis, is the entrance into the urethra
- the frenulum, at the base of the glans, is a y-shaped, membranous area where the foreskin attaches to the penis
- the bottom ridge of the glans, the corona, may also be quite sensitive
Inside the Penis – What you can’t see
Inside the shaft of the penis are the following major features: the urethra, the corpus spongiosum, and the corpora cavernosa. The urethra is a soft tube that carries urine away from the bladder or – at other times – carries ejaculate out of a man’s body. (Don’t worry! These don’t happen at the same time.)
The corpus spongiosum is a chamber of spongy tissue surrounding the urethra. The tissue here is filled with blood vessels and tiny spaces called sinuses that fill with blood during sexual arousal.
The corpora cavernosa are two chambers of spongy tissue that are located on the anterior side of the penis (the side closer to one’s abdomen). Like the corpus spongiosum, this tissue is full of blood vessels and sinuses. During sexual excitement, blood flow increases to the pelvic area which results in the swelling and expansion of these tissues – and, in men, may result in an erection.
Other important parts located internally are the Cowper’s glands (located at the root of the penis) which produce the bulk of pre-ejaculatory fluid, and the prostate gland, which contributes much of the fluids that are found in semen (sperm comprise only a small amount of the volume).
As one of our former sex educators used to say, “weird name, important sack.” The scrotum is a sack of skin that contains the testes and the epididymis. The testes (or testicles) are glands that contain the seminiferous tubules, which produce sperm, and that play an important role in manufacturing hormones such as testosterone.
Wrapped around the back of the testicles is the epididymis, a holding area for mature sperm. The epididymis narrows into the vas deferens. The vas deferens carries sperm from the testes to the ejaculatory duct. There, the sperm mixes with semen and – if a man ejaculates – then it travels through the urethra and out of the body.
Monthly self-examination of the testicles may help with the early detection of testicular cancer. A good time to examine one’s testicles is after a warm bath or shower. The heat from the water relaxes the scrotum, making it easier to find a lump or anything unusual. If you have questions about how your scrotum or testes feel, or concerns about something you have found, please contact your healthcare provider.
Other Male Body Issues Related To Sexuality
Many men ask us questions about their penis size. They may wonder if their penis is too short or long, or too thin or thick. They also sometimes ask about the direction that it points or a certain way that it bends.
There are dozens of studies that have examined penis size in the past century. One of the more famous studies is data presented by Dr. Alfred Kinsey and his colleagues in the 1948 book Sexual Behavior in the Human Male (data which were later included in a separate analysis, in 1979, by Drs. Gebhard and Johnson).
A review of penile size research found that the average erect penis is about 5.5 to 6.2 inches long and about 4.7 to 5.1 inches in circumference. Keep in mind that this size is for an erect penis, not a flaccid (soft) one. Though some men worry about the size of their genitals in relation to their ability to be a “good enough” lover, factors such as relationship satisfaction, technique and the psychological aspects of the sexual experience (e.g., excitement, love, fantasy) tend to be more important to sexual satisfaction than the size of one’s genitals.
You might have heard it said that some men are “grow-ers” and some are “show-ers”, meaning that flaccid penis size may or may not relate to the size of the erect penis. A penis that doesn’t gain much length with an erection has become known as a “show-er,” and a penis that gains more length during an erection is said to be a “grower.”
And as far as science is concerned, we still have a lot to learn about penis size and the potential to safely or effectively alter it. Most so-called penis enlargement products such as pills, weights and stretching devices have not been scientifically tested to determine if they work or – more importantly – if they are even safe to use. Even penile augmentation surgeries to enlarge the penis either in length or circumference are not considered “safe and effective” by major American medical organizations. In fact, surgery may cause scar tissue to grow that can cause a painful or even a shortened erection.
That said, as research changes so does our knowledge. A study published in a 2009 issue of the British Journal of Urology suggested that it may be possible to stretch the length of the penis, however this was a preliminary study and more research is needed on the long-term safety issues of using such a device and its effects on men’s erectile function.
Some people have heard that using a penis pump may result in a larger penis, but again there is no evidence that this is true. Because the penis is composed largely of spongy erectile tissue and not of muscle, it cannot be strengthened or “built up.” There is also some concern about the safety of using penis pumps, as some men have experienced penile pain or inflammation as a result of their use. Ask your healthcare provider if you have questions or concerns about the use of penis pumps.
For more information, see the Kinsey Institute’s comprehensive list of penis size studies here.
Technically, circumcision is the surgical removal of the skin (called the foreskin) that normally covers and protects the head, or glans, of the penis. Circumcision is practiced for a variety of reasons, including cultural and religious reasons for groups such as Jews and Muslims. There may be some health benefits to circumcision, such as slightly lower rates of urinary tract infections, sexually transmissible infections (STI), including HIV, and cancer of the penis. However, the American Academy of Pediatrics, still does not make recommendations for or against circumcision and research is ongoing to determine the potential benefits – or risks – of this procedure. There are also various advocacy groups that are working to end circumcision as a routine practice for male babies.
Circumcision is the most common surgical procedure in the United States. Circumcised and uncircumcised penises may look somewhat similar when erect and function in essentially the same way; an uncircumcised penis has the extra skin while flaccid or semi-erect. If good hygiene is not practiced among uncircumcised men, secretions from glands in the foreskin can accumulate, causing odor and sometimes infections. For more information on circumcision, check out the World Health Organization’s website on male circumcision.
The anus (opening of the anal canal) functions as eliminator of waste, sexual organ, and intake orifice for treatment (e.g., suppository, enema). If you decide to engage in anal play during sexuality activity, you should know a bit more about the anatomy of the anus.
The anal canal is the first 2 inches of skin after the anus, the opening to the canal. The anus is closed while at rest and open during defecation and penetration. This leads to the rectum (approximately 5 inches long and 1 1/2 inches wide), the cavity that runs vertically, and in a curved shape, from the end of the colon to the anal canal.
Although many people are comfortable examining their genitals (the vulva for women and the penis and scrotum for men), not as many people have experience looking at, touching or examining their anal area. To do so, it can be helpful to find a well-lit space and to sit down on the floor or one’s bed and use a mirror to examine the area of skin around the anal opening. As with other genital self-examinations, if you notice any soreness, pain, new bumps or areas of skin color changes, it is recommended that you bring these to the attention of a healthcare provider.
More casually known as bent or curved penis, Peyronie’s disease affects around 5 million men in the United States. Peyronie’s disease affects the shape of a penis, which can become curved, shortened or indented as a result. A slight bend, curve or twist in the shaft of a penis is completely normal and natural. But Peyronie’s generally develops after a sexual trauma and can lead to a much more drastic shape.
The problem develops over a series of months or years as a lump of plaque or scar tissue builds up under the skin of the penis’ shaft. This process can be painful. In some cases, the build-up stops progressing after a few months or can even reverse and disappear on its own. In some cases, the increase of plaque may force further bending. The curve resulting from Peyronie’s disease is obvious when the penis is erect. Therefore, many men do not notice the start of Peyronie’s until intercourse becomes painful for his partner or him.
Peyronie’s is most common in men 45 to 65 years old. There’s more thorough information on treatment alternatives on the menshealthpd website.