The Everything Orgasm Book (7 page)

The Cervix

The cervix is the tip of the uterus that can be felt at the back of the vagina. It is made up of very strong muscles and has no nerve endings on its surface. The opening in the center of the cervix is called the os. It is through the os that sperm enter the uterus and menstrual blood exits the uterus. In childbirth, an infant can pass through a greatly dilated os to the vaginal canal.

The Vagina

The vagina is made up of extremely expandable tissue, which forms a canal, about four inches long, extending into the body and angling upward toward the small of the back. It is considered a potential space. Most of the time, its tissues rest against themselves. It expands only during high states of arousal or childbirth. The tissue of the outer third of the vagina is comprised of numerous ridges and folds. This outer third has more nerve endings than the rest of the vagina and is consequently the most sensitive portion. The tissue of the inner two-thirds of the vagina is much smoother. It is less sensitive to light touch, friction, or vibration, but it is still very responsive to pressure. The vagina has many functions: One is to allow for penetration for pleasure or procreation, another is to carry menstrual flow out of the body, and another is to serve as a birth canal.

The Skene's Glands

The Skene's glands, also known as the lesser vestibular or paraurethral glands, are located on the anterior wall of the vagina, near the lower end of the urethra. They vary in size from one woman to another and appear to be missing altogether in some women. The Skene's glands are the female version of the prostate gland in males. They produce a clear or milky fluid that is similar to the fluid the prostate generates in males. In women who ejaculate, this fluid is released into urethral tract and expelled from the urethral opening. Because of the similarities, many researchers are beginning to refer to the Skene's glands as the female prostate. The location of the Skene's glands is also known as the G-spot (the Grafenberg spot) and the general area is that of the urethral sponge.

The Urethral Sponge

The urethral sponge is the spongy cushion of erectile tissue surrounding the urethra. During arousal, it becomes engorged with blood and compresses the urethra, helping to prevent urination during sexual activity.

While a man's sexual anatomy is a lot more out in the open than a woman's, there is still a lot that men may not understand about their genitals and how they function. Learning more about your sexual anatomy can help you expand your awareness of the many possibilities for sexual pleasure that may yet be undiscovered. Just as that of women, male sexual anatomy can also be divided into internal and external genitalia.

The external male genitals consist of the penis, the scrotum, and the urethral opening. You are probably aware of this much, but you may lack knowledge of the more intricate details of this part of your anatomy and its physiology.

The Penis

The penis is the main source of sexual pleasure for males. It is made up of three columns of spongy erectile tissue — two corpora cavernosa or cavernous bodies and one corpus spongiosum or spongy body. These columns become engorged, or filled with blood, when a man is sexually aroused, making the penis erect. This prepares the penis for intercourse or any other penetration.

The penis is made up of several different parts, each of which has its own unique capacity for sexual arousal and pleasure. These parts include the head or glans, the urethral opening, the foreskin, the corona, the frenulum, and the shaft.

The Glans

The glans or head of the penis is the rounded part at the end of the shaft. It is a highly sensitive area with many nerve endings. The glans of the penis is developed out of the same tissue as that of the glans of the clitoris. At the tip of the glans is the urethral opening where urine expels itself from the body.

The Foreskin

The foreskin, or prepuce, is the double-layered fold of skin that covers the glans in a flaccid penis. It is like the clitoral hood that covers and protects the clitoris on the female. The foreskin retracts to just below the glans when the penis is erect. It protects the glans and the frenulum, keeping these tissues lubricated and shielded from abrasion or injury. Many men have had their foreskins removed when they were infants in a process called circumcision. In circumcised men, the glans is therefore exposed at all times.

The Frenulum

The frenulum is the indentation found on the underside of the penis where the glans and the shaft meet. The frenulum is a highly sensitive area for most men.

The Corona

The corona, sometimes called the coronal ridge, is the ridged band that separates the head of the penis from the shaft. It is a highly innervated smooth muscle that radiates from the frenulum and surrounds the inner tip of the foreskin. It contains approximately 80 percent of the male erogenous tissue and is extremely sensitive to light touch, stretching, folding, pressure, and temperature. When the foreskin is pulled back, the ridged band lies just behind the crest of the glans.

The Shaft of the Penis

The shaft is the part of the penis that extends out from the body to the head of the penis. When it is flaccid, the skin on the shaft is loose and stretchy. Unlike the skin everywhere else on the body that attaches to the underlying tissues, the foreskin and the skin on the shaft are loose and can glide freely along the shaft of the penis, which reduces friction and abrasion and keeps the lubricating fluid flowing during stimulation, intercourse, or other penetration.

The Scrotum

The scrotum, or scrotal sac, is a thin-walled muscular pouch that has two compartments to house the testicles and is located underneath the penis. One of its functions is to maintain the testicles at a temperature slightly below the rest of the body's temperature. This is achieved through a process known as the cremasteric reflex. This reflex causes the scrotum and testes to pull in closer to the body for more warmth or release further away from the body to cool down.

As in the female, the internal genital structures of the male are primarily concerned with reproduction. The internal genital organs or structures are the testicles, the urethra, the epididymis, the vas deferens, the seminal vesicle, the ejaculatory duct, the Cowper's glands, and the prostate.

The Testicles

The testicles, also referred to as the testes, produce both sperm and male sex hormones. They are the male counterpart to the female's ovaries. The testicles are contained within the scrotum, or the scrotal sac or pouch. They are usually very sensitive to impact but can also be pleasurably fondled.

The Epididymis

The epididymis is a narrow, tightly coiled tube that connects the back of the testicles to the vas deferens, through which semen flows during ejaculation.

The Vas Deferens

The vas deferens are two ducts that pass above and behind the bladder. They provide temporary storage for sperm and they are responsible for propelling sperm during ejaculation.

The Urethra

The urethra is the last part of the urinary tract, ending at the tip of the penis. Its function is to allow the passage of urine and semen.

The Prostate

The prostate is the gland that surrounds the urethra just below the bladder. When healthy, it is about the size of a walnut. It is responsible for secreting some of the fluids that make up the semen.

The Seminal Vesicles

The seminal vesicles are a pair of glands located behind the bladder in the male. They are responsible for secreting a large portion of the fluid that ultimately becomes semen.

The Ejaculatory Ducts

The ejaculatory ducts are the channels that join the vas deferens and the seminal vesicles. They pass through the prostate gland and drain into the urethra. During ejaculation, the semen passes through these ducts and out of the body through the penis.