What Is the Foreskin?

by Paul M. Fleiss, M.D., Frederick M. Hodges

CHAPTER ONE

Anatomical and Physiological Facts That Your Doctor May Not Know

The prepuce is a common anatomical structure of the male and female external genitalia of all human and non-human primates; it has been present in primates for at least 65 million years, and is likely to be over 100 million years old, based on its commonality as an anatomical feature in mammals.
Christopher J. Cold, M.D., and John R. Taylor, M.D.

What Is The Foreskin?

The foreskin-also known as the prepuce is the flexible, doublelayered sheath of specialized skin that covers and protects the glans (or head) of the normal penis. The foreskin is a uniquely specialized, sensitive, and functional organ of touch. No other part of the body serves the same purpose.

The foreskin is an integral and important part of the skin system of the penis. It is a complex and sophisticated structure with many interesting and unique properties. No other part of the body's skin covering duplicates the amazing design and functional possibilities of the foreskin. Among the many interesting features of the foreskin is the fact that it is highly elastic, entirely devoid of any subcutaneous fat, and lined with a sheet of smooth muscle.

The foreskin is more than just skin; it is a complex, highly mobile, and beautifully engineered organ composed of an intricate web of blood vessels, muscle, and nerves. In fact, the foreskin contains about 240 feet of nerve fibers and tens of thousands of specialized erotogenic nerve endings of various types, which can feel the slightest pressure, the lightest touch, the smallest motion, the subtlest changes in temperature, and the finest gradations in texture.

Nature has designed the delicate glans (commonly called the head of the penis) to be an internal organ. In the normal, intact penis, the glans is a glistening, rich red or purple color. The foreskin protects the glans and keeps it in excellent condition.

In many ways, the foreskin is just like the eyelid. It covers, cleans, and protects the glans just as the eyelid covers, cleans, and protects the eye. Also, just as the eyelid can open and close to uncover the eye, so the foreskin can open to reveal the delicate glans. The foreskin's inside fold is lined with a smooth red tissue called mucous membrane. This type of tissue is also found lining the lips, the inside of the mouth, and the inner fold of the eyelid. The foreskin's soothing inner fold gently keeps the surface of the glans healthy, clean, shiny, warm, soft, moist, and sensitive.

What Is The Tubular Tip Of The Foreskin Called?

The akroposthion is the useful name that the ancient Greeks gave to the tubular, tapered “neck” of the foreskin that extends beyond the glans (head). The akroposthion smoothly extends beyond the glans, forming a soft, tapered, tubular sheath. This akroposthion of the foreskin functions as an extension of the urethra and conveys urine from the meatus (the urinary opening in the glans) to the outside world. The akroposthion varies in length between individuals. In childhood, it can represent at least half the length of the penis. Some boys have a foreskin that extends an inch or more beyond the glans. In other males, the akroposthion can be almost nonexistent, in which case the meatus and the surrounding portion of the glans may be exposed. Whatever the case, all lengths are normal.

About the Author

PAUL M. FLEISS, M.D., lives in Los Angeles, California.

FREDERICK M. HODGES, D.Phil, lives in New Haven, Connecticut.