Penis Anatomy                                                            

What makes up the anatomy of the penis?

The male penis is a complex structure of tissues that fill up with blood when the penis is sexually aroused. Besides sexual functions, the penis is also an important part of the "drainage system" of the male body.

What is the anatomy of the penis like? You must heard or read of the corpa cavernosa, of testes & testicles and even od vas deferens . But what do they do?

Find out in this article for on the penis anatomy for a fascinating journey

Penis Anatomy and Glossary

To understand how penis enlargement works, it is helpful to know how the penis is made up, how it works and so on.

There are two main chambers to the penis that make up the corpora cavernosa. These chambers get filled with blood during arousal, and the tissues become engorged. The expansion of these chambers puts pressure on the tunica albuginea and the blood is trapped in the corpora cavernosa, hence the penis becomes erect. This is how erection happens.

The corpus spongiosum also fills with blood, but to a lesser extent compared to the corpora cavernosa. This is to protect the fine tissues of the urethra, and to permit ejaculation.

The capacity of the corpora cavernosa is crucial in determining the size of an erect penis. The erect penis can only become as large as the chambers itself. Most penis enlargement methods (other than surgery) hope to increase the capacity of these chambers so as to allow more blood into the penis during an erection.

Corona: 
  • The 'crown,' a ridge of flesh demarcating where the head of the penis and the shaft join.
Corpa Cavernosa:                                                             
  • The corpora cavernosa are the two spongy bodies of erectile tissue on either side of the penis. These become engorged with blood from arteries in the penis during arousal, thus causing an erection.
Corpus Spongiosum:             

  • The spongy tissue surrounding the urethra. This tissue expands to protect the urethra when filled with blood but not as much as the corpora cavernosa.
Cowper's Glands:   

  • The Cowper's glands secrete a small amount of pre-ejaculate fluid prior to orgasm. The functon of this fluid it to neutralize the acidity within the urethra itself.
Dorsal Side: The top or upper side of the penis.

Ejaculatory Ducts:        

The path through the seminal glands which semen travels during an orgasm.

Epididymis:         

  • The 'holding pen' where sperm produced by the seminiferous tubules mature. The sperm are held here until ejaculation or nocturnal emissions (wet dreams) happens.

Foreskin Prepare:
  • A roll of skin which covers the head of the penis in uncircumsized men.
Frenulum, Frenum:       

  • A thin strip of flesh on the underside of the penis that connects the shaft to the head.
Glans:                                                      

 
  • The glans is the head of the penis. The glans in uncircumcised men is usually covered by the foreskin. The glans is highly sensitive, as is the corona, the ridge of flesh that connects the glans to the shaft of the penis.
  • Head: Also known as the glans, this is the bulbous tip of the penis.
Meatus:

  • The opening at the tip of the penis to allow the passage of both urine and semen.
Perineum:                                                                            

  • The area between the scrotum and anus.

Prostate Gland:                                                                     
  • This gland produces a fluid that makes up the semen. The prostate gland also shuts the urethral duct to the bladder in order to prevent urine from mixing with the semen and disturbing the pH balance required by sperm.

Pubococcygeus Muscle:                                                     
  • Also known as the PC or pelvic floor muscle. Necessary to control urination and ejaculation.
Raphe:                                                               
  • Visible ridge running from the meatus to the perineum across the scrotum. Is formed during fetus development and gender assignation.
Scrotum: 

  • The scrotum is a sac that hangs behind and below the penis. Commonly called the balls. It contains the testes, the male sexual glands. The scrotum's main role is to maintain the testes at approximately 34 C . This is the temperature in which the testes can most effectively produce sperm.

Semen:

The fluid produced during ejaculation. Made up of 2-5% sperm. The main bulk of semen is seminal plasma, with large concentrations of Zinc, and amines that protect the sperm from the acidic environment of the vagina.

Seminal Vesicles

The seminal vesicles produce semen, a fluid that activates and protects the sperm after it has left the penis during ejaculation.

Shaft:                                                                                                              

The main length of the penis made up of the corpora cavernosa, corpus spongisum, urethra, cavernosal artery and dorsal vein and artery.

Smegma:                         

A substance with the texture of cheese made up from oils secreted by glands on each side of the frenulum, combined with skin cells, and moisture. This usually only occurs in uncircumcised men.                                                           

A substance with the texture of cheese made up from oils secreted by glands on each side of the frenulum, combined with skin cells, and moisture. This usually only occurs in uncircumcised men.         

  • The male sexual glands, the two testes within the scrotum produce sperm and testosterone. Within each testis is a kilometer of ducts called the seminiferous tubules, the organs which generate sperm. Each testicle produces nearly 150 million sperm every 24 hours.

Urethra:                                                                       

  • Passageway of the penis, carrying urine from the bladder and semen from the testes to the tip of the penis.

 

Vas Deferens:                                                           

  • The ducts leading from the epididymis to the seminal vesicles. These are the ducts that are cut during the procedure known as vasectomy.

Human Penis Size

The general rule with respects to male penis size is that it is usually proportional to the size of the body. Results typically vary across study, usually a result of participant bias. Studies have shown that the average penis size ranges between 5 to 5.5 inches erect.

Variations of Penis Size

While there have been studies on the size of the penis at erect length, there have been very few pertaining to flaccid size. This typically varies amongst men however the most recent study noted a flaccid length of approximately 3 inches.                                                               

Penile stimulation

The most important components of the physical erogenous stimulation of the penis during foreplay and intercourse are the sensations from the foreskin, frenulum/frenar band, and glans. These structures each have their own feeling, and each contributes in its own way to the man's total experience of lovemaking. It must be emphasized that emotional excitement is an extremely important component of sexual enjoyment, and intensifies the man's perception of any physical sensations from his penis.

  • The foreskin has an inner and outer layer. The outer foreskin layer contains nerve endings which respond to gentle touching during the early stages of sexual arousal. This helps to trigger an erection. The nerves of the inner and outer foreskin contribute to the experience of penile stimulation, up to and including orgasm. These receptors are stimulated by stretching, or when the foreskin rolls over the surface of the glans during intercourse or masturbation. (see `the gliding mechanism,' below).
  • The foreskin contains sensory receptors called Meissner corpuscles. We believe that these nerves, similar to nerve endings in the fingertips, are there to provide pleasure, as well as fine sensory perception. This seems to help a man to enjoy sex longer without ejaculating prematurely, because he can more easily tell when he is approaching the threshold of orgasm.
  • Stimulation of the frenulum and ridged band results in intense pleasurable feelings during arousal. The ridged band consists of a number of "ridges", described by Dr. John Taylor in his recent article. Sensations from these structures during intercourse or masturbation are thought to be the primary trigger of orgasm in the intact male. Dr. George Denniston writes:

The ridged bands, which are like horseshoes only in that they curve forward underneath toward the point where the frenulum attaches, can be found in several pictures in John's paper. There are some 20 concentric ridged bands which rub over the corona. Each ridge has Meissner's corpuscles, which respond to pressure, and they produce the sexual pleasure which no individual has a right to take away from another individual.

  • We believe that stimulation of the glans is most significant in the later stages of sexual intercourse, when penetration is deepest and emotions are running at their highest. Sensations from the glans contribute to the quality of the sensual experience. They are also apparently capable of triggering orgasm on their own, as would be the case in a circumcised man.                                                                     

Circumcised adult penis

The circumcised penis: Erect state

Following circumcision, the foreskin of the penis has been cut away. The surface of the glans has developed a thick, dry layer of keratin (toughened skin), which makes it less sensitive to unwanted stimulation, but also less sensitive to the more subtle qualities of lovemaking.

All circumcised men have an annular scar on the shaft of the penis. The location of the scar varies, from near the head to far down the shaft. For some men, so much skin has been removed that erection becomes difficult and even painful. This was one of the most common complaints reported by circumcised men in a recent poll.

The gliding mechanism

During intercourse the loose skin of the intact penis slides up and down the shaft of the penis, stimulating the glans and the sensitive erogenous receptors of the foreskin itself. On the outstroke the glans is partially or completely engulfed by the foreskin.

This is known as the gliding mechanism.' 

The gliding mechanism is Nature's intended mechanism of intercourse. As such, it contributes greatly to sexual pleasure. Also, since more of the loose skin of the penis remains inside the vagina, the woman's natural lubrication is not drawn out to evaporate to a great extent, which makes sex easier without using artificial lubricants.

The prepuce is a highly innervated and vascularized genital structure. It is entirely lined with the peripenic muscle sheet. Specialized ecoptic sebaceous glans on the inner preputial surface produce natural emollients and lubricants necessary for normal sexual function. The primary orgasmic triggers are found in the preputial orifice and frenulum. When unfolded, the prepuce is large enough to cover the length and circumference of the erect penis and acts as a natural sheath through which the shaft glides during coitus. Only the presence and functions of the prepuce allow for physiologically normal coitus to occur as designed by nature.