Your Penis Guide
Although the penis is a rather ordinary, everyday organ (at least for about 50% of the population), it is surprising how little some people know about this part of the body. In some animals, the penis is equipped with a small bone, but not so in humans. In the adult male, the penis is about 2 to 3 inches long, although this can differ from day to day. When it is cold, the penis can withdraw into the fatty tissue overlying the pubic bone, which makes it seem shorter, especially in men with a lot of fat there. There is generally little variation in the 'real' length of the penis between different men; in some races, it's somewhat longer, and in others a bit shorter. During erection, the penile length varies between 6 and 8 inches.
Published after getting Permission from the copyright Owner William Westwood.
Three major structures can be found in the penis: the urethra and two long cylinders, the erectile bodies.
The urethra, with a thick, spongy cylinder around it, is located below. The urethra is designed to conduct urine to the outside world, but can only be considered a tube when it does; after the urine is expelled, the elastic fibres in its wall make sure it collapses. The tube ends at the glans of the penis. The skin on the glans is very sensitive and is normally protected by the foreskin, which acts as a cover. The foreskin should be able to slide back and forth over the glans easily, although this is not always the case yet in children. To ease the sliding, small glands produce a kind of grease. When this area of the body is not cleaned regularly, the grease may become noticeable as smegma. In the middle of the lower part of the foreskin, a small skin slip can be found (Latin: frenulum), running from the foreskin towards the opening of the urethra; the function of this slip of foreskin is unknown, but sometimes it can be painful during erections when it is too short.
The erectile bodies, long cylinders, that are located next to each other at the 'back' of the penis. They contain blood. During an erection, the amount of blood inside the cylinders increases, because the inflow increases and the outflow of blood decreases; the cylinders are filled to the limit with blood and will stand upright, causing the erection of the penis; it works just like those cylindric balloons. To ensure a good blood supply, several blood vessels run towards the erectile bodies and a dense web of small nerve fibres ensure the opening and closing of the right vessels during erection. Since there are no stiff structures, like bones or something similar, in the penis to give it rigidity, the penis is connected to the pubic bone by strong connective tissue; because of this, the erect penis is still rather stable and pointing slightly upwards.
Scrotum and Testicles
The scrotum is the loose pouch of skin containing the testicles (or “balls”), which produce sperm and testosterone. Because the testicles are extremely sensitive to pain, the scrotum acts as a protective incubator, keeping the testicles warm so they can function effectively. The epidermis is a coiled tube within the testicles where sperm mature until they travel through the vandeferens before they are ejaculated during sexual arousal. Men have two testicles; it is not uncommon for one to hang lower than the other. A lot of men enjoy gentle stimulation of the testicles, which can involve licking, tugging, or simply cradling the scrotum.
Prostate Gland
The prostate gland produces ejaculatory fluid and is located close to the root of the penis and below the bladder. Because of its close proximity to the rectum, many men enjoy prostate stimulation by inserting a finger or toy into the rectum and stroking toward the front of the body. Some men can orgasm from prostate stimulation alone, while others find it enhances other types of sexual activity.
Perineum and the Anus
The perineum lies between the anus and the penis; massaging the perineum using a firm stroke or direct pressure can stimulate the sensitive root of the penis. The anus is rich in nerve endings and can respond sexually when stimulated with fingers, tongues, or toys. The anus is about an inch long and leads to the rectum, which is between five and nine inches long. Entrance to the anus is regulated by two sphincter muscles which you can learn to relax, so you can enjoy anal intercourse, butt play, or prostate stimulation. Just make sure anything you put in the anus is well-lubricated and has a flared base. The rectum is not sealed at one end, so anything inserted without a flared base could potentially be pulled up into the colon.
PC Muscle
The pubic bone is surrounded by the pubococcygeus muscles (otherwise known as the “PC muscle”) which play a vital part in your sexual health. Locate the PC muscle by stopping a stream of urine, and then letting it go again. You can exercise your PC muscle by doing kegel exercises (repeating this "squeezing" motion several times in a row). It helps men learn ejaculatory control and can lead to stronger erections.
Function
As you will undoubtedly know, the penis has three functions:
Urinating. This is a rather plain and simple function, where the penis serves as an extension of the urethra, thus enabling males to urinate easily anywhere they want without spilling any urine. In women, this is more difficult and they will have to find a place to squat.
Sexuality. Simply put: an erect penis, i.e. a stiff one, can give pleasure. Having an erection is, however, a complicated procedure. In order to have an adequate erection three conditions must be fulfilled:
a certain amount of lust is required (Latin: libido) a good inflow and outflow of blood is necessary the management, i.e. the nerve supply, must be functioning properly Getting and maintaining an erection is an automated process. It is mainly run from the nerve cells in the spinal cord. Of course, the owner of the penis does have some say in it, but only up to a limit, for instance by thinking or not thinking about someone/something (porn movies). The effects will generally be limited to erection or no erection; it is pretty hard to want to have only a bit of an erection. To show that the erection is governed by the spinal chord one can use a vibrator. The vibrations of the machine will excite the nerve endings in the glans of the penis and will elicit an erection via a reflex mechanism in the spinal cord (just like the knee-jerk reflex causes automatic contraction of the muscles in the leg). The 'erectile nerves that run from the spinal cord to the penis will cause the inflow of blood to the erectile bodies to increase and the outflow to decrease, thus filling these bodies with blood and causing the erection of the penis. If there is no sense of lust, the inflow of blood is too low or the nerves to the penis are damaged, then the erection will be limited or even non-existing.
Reproduction. In terms of evolution, erection has proven to be a good method to put male sperm into a woman's womb. In ejaculation (coming) an amount of semen (prostatic fluid + sperm cells) is ejected into the urethra at the level of the prostate. The semen is propelled through the urethra by rapid muscular movements in its wall and ejected through the penis, on its way to the female egg cell; to prevent the semen from going the wrong way (to the bladder, which is closer by) the entry to the bladder is closed by a tiny sphincter at that very moment - that is the reason that ejaculation and urinating at the same time is impossible. Ejaculation is not called 'coming' for anything: according to mother nature the goal is reached the very moment the semen came and erection is not needed any further.