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Male Sexual Anatomy

While a bits and functions understanding of anatomy is important, it’s also important to be familiar with the basic anatomy because during high levels of sexual excitement many men will begin to feel changes in our reproductive anatomy.

External structures:

Most guys are familiar with the external anatomy, but it’s helpful to review the details a bit—especially since some of these details are really handy to know for our pleasure. These structures include the penis, scrotum, and the testicles.

The Penis

Penile AnatomyLet’s start with the penis. It’s comprised of nerves, blood vessels, fibrous tissue, and spongy tissue. There is no bone and little muscular tissue (although there are muscles at the base of the penis where it attaches). Many guys are surprised to learn that the penis extends significantly inside the body. In fact at least half the length of the penis is internal. The root of the penis is attached to the abdominal wall; the body of the penis consists of three cylindrical chambers. The two larger ones, the corpora cavernosa, are side by side. The third chamber, the corpus spongioum surrounds the urethra. The glans is the cone or mushroom shaped end.

The entire penis is highly sensitive—including the internal portions. We’ll get to this in a bit. Of course, the glans is highly sensitive, as is the ridge around it, known as the corona or the coronal ridge. The frenulum, the soft area underneath the corona, is the most sensitive part on most men.

The meatus (this term actually applies to any body opening) is the opening for both urine and semen. Some men find this area particularly sensitive too. Other guys, though, find touch here a bit irritating.

Internal structures:

Male AnatomyOften we aren’t as familiar with what’s on the inside of the body. During sexual excitement, and especially, edging, many men will begin to feel changes internally. So a basic understanding of internal anatomy is useful as you become aware of your own erotic energies.

The Scrotum

The scrotum is made up of two pouches enclosing the testes. The walls of the scrotum are comprised of two layers: a skin layer and muscle layer. Its primary purpose is to regulate the temperature of the testes for optimum sperm production. Normally the scrotum hangs loosely from body wall, but cold temperatures and sexual stimulation will cause it to move closer to the body

The Testicles

The testicles are oval organs that lie in the scrotum. The testes are responsible for making testosterone, the primary male sex hormone, and for generating sperm. Most men have two testes and the left one usually hangs lower than the right one. Within the testes are coiled masses of tubes called seminiferous tubules. These tubules are responsible for producing the sperm cells through a process called spermatogenesis.

The spermatic cord secures the testes at either end. It contains the vas deferens, blood vessels, nerves, and muscle fibers. The spermatic cord can be located by gently kneading the scrotal sac above either testicle with thumb and forefinger.

The epididymis is a long, coiled duct that rests on the backside of each testicle. It functions in the transport and storage of the sperm cells that are produced in the testes. It also is the job of the epididymis to bring the sperm to maturity, since the sperm that emerge from the testes are immature and in-capable of fertilization.

The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity, to just behind the bladder. During sexual arousal, contractions force the sperm into the vas deferens which transports mature sperm toward urethra in preparation for ejaculation.

The seminal vesicles are sac-like pouches that attach to the end of vas deferens near the base of the bladder. The seminal vesicles produce a fluid that makes up most of the volume of ejaculatory fluid. When aroused, nerves stimulate muscle contractions along the vas deferens, the seminal vesicles and the prostate. During sexual excitement it can be especially pleasurable to notice the seminal vesicles and the prostate firm up as they fill with ejaculatory fluid. Many men don’t notice this sensation; however, with practice and attention, this can most definitely be felt and can send joys of delight through the body.

The prostate gland is a walnut-sized structure that is located below the urinary bladder in front of the rectum. In most men the prostate enlarges as we age – in most cases there’s nothing to worry about but, if you’re over 50, be sure to have your prostate checked by a medical professional. The prostate gland contributes additional fluid to the ejaculate. Prostate fluids also help to nourish the sperm. The urethra, which carries the ejaculate to be expelled during orgasm, runs through the center of the prostate gland; this is why the feeling during prostate massage is similar to the feeling when you have to urinate. The bulbourethral glands, or Cowper’s glands, are pea-sized structures located on the sides of the urethra just below the prostate gland. These glands produce a clear, slippery fluid that empties directly into the urethra. This fluid, commonly referred to as pre-cum, serves to lubricate the urethra and neutralize the acidity of urine. Some men produce a lot of pre-cum; others may not produce as much.

The prostate gland is a great place for generating erotic energy. We’ll focus a lot on this area during anal touch. For now though, the prostate can be massaged from the perineum. The perineum is between the base of your balls and your anus. The internal part of the penis runs just on the inside of this wonderful part of the body. You can definitely feel the internal penis by massaging here — especially when you’re hard.

The urethra, which carries the ejaculate to be expelled during orgasm, runs through the center of the prostate gland. Urine also travels through the urethra on its way out of the body from the bladder.

The bulbourethral glands, or Cowper’s glands, are pea-sized structures located on the sides of the urethra just below the prostate gland. These glands produce a clear, slippery fluid that empties directly into the urethra. This fluid, commonly referred to as pre-cum, serves to lubricate the urethra and neutralize the acidity of urine. Some men produce a lot of pre-cum; others may not produce as much.

The perineum is between the base of your balls and your anus. The internal part of the penis runs just on the inside of this wonderful part of the body. You can definitely feel the internal penis by massaging here—especially when you’re hard.

You can also do a nice prostate massage from here. Press on the spot about halfway between the base of your balls and your anus then, with firm pressure, gently massage the area. You will feel a pleasant sensation a bit inside your body from this spot. This is your prostate.

A Physiological View of Ejaculation

It’s pretty amazing all the things that happen during an ejaculation. Ejaculation is actually a two-stage process.

First, there’s emission, where the semen moves out from the seminal vesicles into the base of the penis. A few seconds later is the propulsion phase, where the semen leaves the meatus of the penis and is propelled out.

During the emission phase, the muscles of the vas deferens contract more to propel sperm towards the prostate. Secretions emitted from contractions of both the seminal vesicles and prostate combine with the contents of the vas deferens as they come together in the base of the penis. These fluids combine to form semen. Pressure builds in the prostate. Then the bladder sphincter is closed—preventing semen from going into the bladder. At this point, a man gets that familiar sense of ejaculatory inevitability—most men recognize this place as the point of no return—you are going to cum and there’s nothing that will stop it.

This is when the propulsion phase takes over. The powerful ejaculation of semen is mediated by nerve complexes in the spine, stimulated by the sensory nerve endings of the penis responding to friction on the touch receptors of the penis. Then the rhythmic wavelike soft-muscle contractions of your PC muscle (remember Kegels?) propel the semen down your urethra and out.

Although these responses are automatic, you can learn to play and modify with these automatic reflexes. This is what conscious pleasure is all about!