Penis and Male Sexuality Facts
The testes, epididymis and other sexual glands
The testes are paired organs which sit in the scrotum and produce sperm and testosterone.
In size, they are roughly 5 cm long and 2.5 cm wide; each one sits in a fibrous capsule, the tunica albuginea, which also serve to divide the testis into smaller areas called lobes.
Each testis has around two to three hundred lobes, and inside them are the seminiferous tubules, where the sperm are actually produced. In among the tubules the Leydig cells secrete testosterone.
All the tubules are connected to ducts which eventually lead to the epididymis and from thence out into the penis.
The Epididymis and the Vas deferens
The epididymis is about 4 cm long and sits on the top of each testicle. It's basically a long thin tube, which would measure more than 6 meters in length if it were straightened out into a line.
Its function is to store sperm, which develop into full maturity as they rest there. they may reside in the epididymis for a month, before they pass in to the vas deferens, where they will travel into the body cavity, around the bladder and onwards to the prostate gland.
The seminal vesicles lie just in front of the bladder, above the prostate gland, and join the vas deferens at the prostate.
They produce around 60% of the volume of semen with a viscous fluid including fructose, prostaglandins and proteins, a mixture which is required to neutralize the acidic environment of the urethra and vagina - sperm cannot survive in these environments.
Fructose is the source of energy for sperm, which they need to swim up the internal passages of the vagina, cervix and Fallopian tubes after ejaculation.
The prostate gland is a small, chestnut-sized organ shaped like a ring around the urethra; it secretes a milky fluid which aids the mobility and survival of sperm. About a third of semen is made up of secretions from the prostate gland.
The prostate gland grows quickly during puberty; it should then remain more or less the same size during adulthood, but it may enlarge in older men, a problem which can put pressure on the urethra, which may lead to dribbling and a poor urine stream.
The prostate is responsible for much of the volume of semen, and a larger quantity of ejaculate can be produced when sexual stimulation continues for some time before intercourse or masturbation. The power of a man's orgasm is greater the more ejaculate he shoots out when he climaxes, so it is well worth learning how he can stop himself coming too soon. Click here to find out more. .
Cowper's glands (bulbourethral glands)
These small glands are located below the prostate; their outgoing ducts pass through into the urethra. They secrete a sticky, alkaline fluid during arousal, and a mucus substance called "pre-cum", which acts as a natural lubricant for intercourse.
Most men do not produce much pre-cum, although in some men it does seep freely from the penis during arousal.