What is Foreskin | Anatomy and Function

and why do humans have it?

by Judy Simone
Intaction Research Writer
July 7, 2022


Everyone is born with foreskin. In males it covers the end of the penis. It can also be called the prepuce. In females it’s called the clitoral hood and surrounds the clitoris. Some cultures or religions advocate cutting off the foreskin, a procedure or ritual known as circumcision. It can also be called genital mutilation depending on perspective. For those that have undergone a traumatizing circumcision, there are no do-overs. That child will have to live his or her entire life never knowing what it would have been like to have this body part. Therefore it is crucial for Americans to fully appreciate the incredible foreskin. It’s a gift embedded in our genetic heritage and what we humans are born with — the foreskin.

What is Foreskin?

The foreskin is a thin sheath of highly specialized skin that extends from the penis shaft and covers the head or glans. Fully adhered to the head of the penis (glans penis) at birth, as a child matures the foreskin separates from the head and can then be retracted or pulled back.  There is no specific time this happens as every child matures at a different rate. The foreskin can remain attached through childhood, but by puberty most foreskins are naturally retractable. 

It’s comprised of a double-layer fold of  skin (epidermis/dermis), muscle tissue (dartos), blood vessels, nerves ,  and a internal mucous membrane. The foreskin is responsible for protecting the head of the penis and the urinary meatus, which is the urinary opening at the tip of the penis. Stretchable and retractable, the foreskin acts just as the eyelid protects and covers the eye. During an erection the foreskin stretches to become some of the thinnest skin on the human body.

Sometimes men with an intact foreskin are incorrectly called “uncircumcised.” The proper term should be “intact” or “natural.” Depending on the foreskin length, coverage of the glans in the flaccid and erect states vary between individuals. The foreskin is a natural body part and medical experts around the world state that in most children and adults it never represents a health issue. Fortunately medical foreskin issues are rare, if they arise, are easily treated.

Foreskin Anatomy

Foreskin contains several significant structures often overlooked and disregarded by medical school anatomy books. The foreskin is chiefly comprised of the outer skin, the inner mucosal skin, the ridged band, frenulum, and dartos fascia.

Canadian anatomical researcher Dr. John R. Taylor discovered the ridged band which is located on the inner layer of the foreskin. There are approximately a dozen “ridges” in the skin that are said to contain over 20,000 specialized nerve endings. These fine touch nerve endings are called Meissner’s corpuscles.” These nerves let a man know what his penis is feeling and how close he is to orgasm. When the foreskin is retracted during an erection, the ridged band becomes outwardly exposed and positioned to send sensory signals to the brain.

During an erection, the ridged band also becomes stretched like an accordion. The stretching of the ridged band triggers important sexual reflexes and erogenous sensation. The highly orchestrated feedback system helps men obtain maximum pleasure while helping them avoid premature ejaculation. A man that has been circumcised (foreskin surgically removed) doesn’t have the sensory input from the ridged band. A cut man’s brain doesn’t receive the sensory resolution of what his penis is feeling during sex.

foreskin anatomy structures diagram

Even More Amazing Anatomy 

People seek answers to the question: What is foreskin? They are often surprised to find out about another interesting feature, a special part called the frenulum. The frenulum is a tough elastic webbed strip of skin that keeps the lower foreskin in place and pulls the foreskin forward to cover the head when the penis is flaccid. The underside (ventral) of the head of the glans penis is contoured which a split channel to accommodate the stretchy webbed frenulum. The frenulum is anchored to this channel.

The frenulum and the area of the underside of the penis (frenula delta) is one of the most sensitive parts of the penis after the ridged band. This was documented in a 2007 study published in the British Journal of Urology (BJU Volume 99, Issue 4, pp. 864–869, Morris L. Sorrells). Unfortunately this highly erogenous part of the penis is entirely removed during circumcision.

foreskin frenulum

The dartos fascia is a thin layer of smooth muscle tissue inside the foreskin. This thin sheet of muscle contracts to allow the foreskin to close and comfortably hug the head of the glans penis when the penis is flaccid.

The frenulum and dartos fascia work together to keep the penis covered and protected with foreskin when not in use !

The foreskin also provides its own lubrication and skin softening emollients. During an erection, the trapped blood pressure in the penis forces fluid (exudate) to leak from the mucosal tissue of the inner foreskin. This provides lubrication during sex, and helps to keep the foreskin and head of the penis moist and supple throughout the day.

Learning Opportunity

Humans have another frenulum which can be found under the tongue. The lingual frenulum is a webbing of skin that keeps the tongue anchored and in alignment inside the mouth.

lingual frenulum foreskin

Foreskin or Clitoral Hood | What’s the Difference?

The male’s foreskin and the female’s clitoral hood are anatomically equivalent but with some differences.

In females, the hood of the clitoris, or clitoral hood, is the fold of skin that surrounds the head of the clitoris.  It protects the sensitive clitoris from friction and rubbing, just like the male foreskin protects the end of the penis. The clitoral hood varies widely in appearance from woman to woman. Larger or smaller hoods are both perfectly normal.

There are some differences between the female clitoral hood and the male foreskin. In the male, the foreskin is more developed and serves multiple functions. The foreskin has more nerve endings, and it provides the expansive skin to aid comfortable erections. The sliding skin also serves a purpose during intercourse, enhancing sensation to help both partners achieve orgasm.  The penis evolved and was designed to penetrate the vagina during sex. The foreskin’s sleeve-like design assists during the thrusting of penetrative sex. The male foreskin also provides sensory feedback with greater definition from it’s nerve endings being in direct contact with his partners body. This helps the male to control his ejaculation.

Foreskin in Infants and Children

The foreskin is fully attached to the glans penis at birth by a thin membrane called the synechia, or Balano-Preputial Lamina (BPL.) As an infant and young child, the foreskin seals the glans from dirt, feces, and urine . The foreskin protects the tip of the penis from irritation caused by abrasion or rubbing against diapers or clothing. As the child matures, the foreskin will begin to separate from the head of the penis. When ready, a boy can be retract or pull his skin back. There is no set age when this happens. While the foreskin may sometimes remain attached through childhood, by puberty most boys can retract their foreskin. A very few men may never achieve retraction of the foreskin. This is called phimosis and can be treated or left alone. 

In any event the infant or child foreskin should never be forcibly retracted. This will result in pain, tearing, bleeding, and scar tissue formation. Parents need to be vigilant and prevent un-informed caregivers from forcibly retracting their son’s foreskin for any reason.

General Foreskin Care for Men and Adolescents

Taking care of your foreskin should be part of daily hygiene. Fortunately it’s easy to do.

  • Clean underneath the foreskin. Without regular cleaning, a build-up of a whitish-yellow substance known as ‘smegma’ can occur under the foreskin. This comes from dead skin cells and skin oils. Smegma can develop an odor if not washed off.
  • Retract your foreskin and wash with warm water. Try to avoid getting soap under the foreskin as it can irritate the skin.
  • See your physician if you have any concerns.

General Foreskin care – Babies and Young boys

Foreskin care is important and young boys should be taught how to care for their penis. Suggestions include:

  • Treat a baby’s penis like any other body part when you give him a bath. Don’t worry about cleaning under the foreskin. Simply wash the penis with soap and rinse. A baby’s or young child’s foreskin cannot retract. Forcing retraction may cause the skin to tear.
  • Do not forcibly pull back a baby’s foreskin. Doing so may cause pain, bleeding, infection or scarring.
  • Change your son’s wet or dirty diaper as soon as possible to reduce the risk of infection.
  • When old enough, teach your son how to clean underneath his foreskin. Tell  him to retract the foreskin for cleaning ONCE IT HAS NATURALLY SEPERATED FROM THE GLANS. Wash and rinse well. Roll the foreskin back over the glans afterwards.


The foreskin is a natural body part that serves important functions. There’s a saying “form affects function.” If the foreskin is surgically amputated, the form  changes. If the form changes, then the way the penis functions also changes. Nature doesn’t make design mistakes, and foreskin is part of our DNA. We must strive to fully understand the benefits of the foreskin, because when we do that, we can appreciate how vital it is to retain it.

Learn even more with this video:

A Woman’s Guide to Foreskin

foreskin women sex function history
foreskin uncircumcised advantages