popcorn
Jan-08-2006, 07:03 AM
I thought i would gather together some information on three topics that are covered (disjointedly) within the topics. They are :-
The Penis (General Info)
Erections (Normal Size...)
And a small amount of info on Ejaculation
Please Enjoy ^.^
THE PENIS and Erections (+Normal Variations of the penis)
The human penis is different from those of other mammals for it has no erectile bone. Instead the male human penis relies entirely on engorgement with blood to reach the erect state. Unfortunatly it cannot be withdrawn back into the groin, and is larger than average in proportion to body mass.
http://upload.wikimedia.org/wikipedia/en/3/35/Male_anatomy.png
The penis is made up of three columns of erectile tissue :-
the two copora cavernosa and
one corpus spongiosum
The corpus spongiosum is located on the underside (ventral side) of the penis and the two corpora cavernosa lie next to each other on the upper side of the penis (dorsal side).
The end of the corpus spongiosum is enlarged and cone-shaped and forms the glans penis. The glans supports the foreskin or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenulum.
The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum and its opening, known as the meatus, lies on the tip of the glans penis. It is both a passage for urine and for the ejaculation of semen. Sperm is produced in the testes and stored in the attached epididymis. During ejaculation, sperm are propelled up the vas deferens, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vas deferens turns into the ejaculatory ducts which join the urethra inside the prostate gland. The prostate as well as the bulbourethral glands add further secretions, and the semen is expelled through the penis.
The raphe is the visible ridge between the lateral halves of the penis, found on the ventral or under side of the penis, running from the meatus (opening of the urethra) across the scrotum to the perineum (area between scrotum and anus).
Relation to female genitals
The glans of the penis is homologous to the clitoral glans, the corpora cavernosa are homologous to the body of the clitoris, the corpus spongiosum is homologous to the vestibular bulbs beneath the labia minora, and the scrotum is homologous to the labia minora, labia majora and clitoral hood. The raphe does not exist in females, because there the two halves are not connected.
Erections
Erection is the stiffening and rising of the penis which occurs in the sexually aroused male, though it can also happen in non-sexual situations. The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters the penis than leaves until an equilibrium is reached (equal volume of blood flowing into the dilated arteries and out of the constricted veins). A constant erectile size is achieved at equilibrium.
Inability to attain a satisfactory erection is known medically as erectile dysfunction, or ED in short. A drug against this condition, sildenafil citrate (marketed as Viagra®) works by vasodilation.
Erection facilitates sexual intercourse though it is not essential for some other sexual activities. Although many erect penises point upwards (see illustration), it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards, depending on the tension of the suspensory ligament that holds it in position. Stiffness of erectile angle also varies.
Size
As a general rule, an animal's penis is proportional to its body size, but this varies greatly between species — even between closely related species. For example, an adult gorilla's erect penis is about 1.5 inches (4 cm) in length; an adult chimpanzee, significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. The common chimpanzee, or pan troglodytes, has the third largest penis size among the great apes: in comparison, the human penis is larger than that of the common chimpanzee, both proportional to body size and in absolute terms; one study has found that the average human penis is 5 inches (12.7 cm) in length when fully engorged with blood during arousal.
As with any other bodily attribute, the length and girth of the penis is highly variable between individuals of the same species. In many animals, especially mammals, the size of a flaccid penis is much smaller than its size when erect. In humans and some other species, flaccid vs. erect penis size varies greatly between individuals, such that penis size when flaccid is not a reliable predictor of size when erect.
Except for extreme cases at either end of the size spectrum, penis size does not correspond strongly to reproductive ability in almost any species.
Normal variations
Depending on temperature, a flaccid (not erect) penis of average size can withdraw almost completely within the body. During erection the penis will return to its normal (erect) size.
Other variations:
* Pearly penile papules are raised bumps of somewhat paler colour around the base of the glans and are normal. See sidebar picture and picture at article.
* Fordyce's spots are small, raised, yellowish-white spots 1-2mm in diameter that may appear on the penis, as well as the inner surface and vermilion border of the lips of the face, and are normal.
* Sebaceous prominences are raised bumps similar to Fordyce's spots on the shaft of the penis, located at the sebaceous glands and are normal.
* Phimosis, an inability to retract the foreskin fully, is harmless in infants and pre-pubescent males, occurring in about 8 percent of boys at age 10.
Ejaculation Facts
Average volume of semen per ejaculation: 2 to 6ml
Average number of times a man will ejaculate in his lifetime: 7,200
Average total amount of lifetime ejaculate: 18 quarts
Its muscle drives nature's only known rotary-joint. The tail SCREWS, not whips. (no pun)
Average number of calories in a teaspoon of semen: 7
Average duration of orgasm: 4 seconds
Average number of sperm cells in the ejaculate of a healthy man: 40 to 600 million
Distance sperm travels to fertilize an egg: 3-4 inches or 7.5-10 centimetres
Sperm lifespan: 2.5 months from development to ejaculation
This inforamtion has been farmed from a well-known free content encyclopedia named wikipedia
The Penis (General Info)
Erections (Normal Size...)
And a small amount of info on Ejaculation
Please Enjoy ^.^
THE PENIS and Erections (+Normal Variations of the penis)
The human penis is different from those of other mammals for it has no erectile bone. Instead the male human penis relies entirely on engorgement with blood to reach the erect state. Unfortunatly it cannot be withdrawn back into the groin, and is larger than average in proportion to body mass.
http://upload.wikimedia.org/wikipedia/en/3/35/Male_anatomy.png
The penis is made up of three columns of erectile tissue :-
the two copora cavernosa and
one corpus spongiosum
The corpus spongiosum is located on the underside (ventral side) of the penis and the two corpora cavernosa lie next to each other on the upper side of the penis (dorsal side).
The end of the corpus spongiosum is enlarged and cone-shaped and forms the glans penis. The glans supports the foreskin or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenulum.
The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum and its opening, known as the meatus, lies on the tip of the glans penis. It is both a passage for urine and for the ejaculation of semen. Sperm is produced in the testes and stored in the attached epididymis. During ejaculation, sperm are propelled up the vas deferens, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicles and the vas deferens turns into the ejaculatory ducts which join the urethra inside the prostate gland. The prostate as well as the bulbourethral glands add further secretions, and the semen is expelled through the penis.
The raphe is the visible ridge between the lateral halves of the penis, found on the ventral or under side of the penis, running from the meatus (opening of the urethra) across the scrotum to the perineum (area between scrotum and anus).
Relation to female genitals
The glans of the penis is homologous to the clitoral glans, the corpora cavernosa are homologous to the body of the clitoris, the corpus spongiosum is homologous to the vestibular bulbs beneath the labia minora, and the scrotum is homologous to the labia minora, labia majora and clitoral hood. The raphe does not exist in females, because there the two halves are not connected.
Erections
Erection is the stiffening and rising of the penis which occurs in the sexually aroused male, though it can also happen in non-sexual situations. The primary physiological mechanism that brings about erection is the autonomic dilation of arteries supplying blood to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters the penis than leaves until an equilibrium is reached (equal volume of blood flowing into the dilated arteries and out of the constricted veins). A constant erectile size is achieved at equilibrium.
Inability to attain a satisfactory erection is known medically as erectile dysfunction, or ED in short. A drug against this condition, sildenafil citrate (marketed as Viagra®) works by vasodilation.
Erection facilitates sexual intercourse though it is not essential for some other sexual activities. Although many erect penises point upwards (see illustration), it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards, depending on the tension of the suspensory ligament that holds it in position. Stiffness of erectile angle also varies.
Size
As a general rule, an animal's penis is proportional to its body size, but this varies greatly between species — even between closely related species. For example, an adult gorilla's erect penis is about 1.5 inches (4 cm) in length; an adult chimpanzee, significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. The common chimpanzee, or pan troglodytes, has the third largest penis size among the great apes: in comparison, the human penis is larger than that of the common chimpanzee, both proportional to body size and in absolute terms; one study has found that the average human penis is 5 inches (12.7 cm) in length when fully engorged with blood during arousal.
As with any other bodily attribute, the length and girth of the penis is highly variable between individuals of the same species. In many animals, especially mammals, the size of a flaccid penis is much smaller than its size when erect. In humans and some other species, flaccid vs. erect penis size varies greatly between individuals, such that penis size when flaccid is not a reliable predictor of size when erect.
Except for extreme cases at either end of the size spectrum, penis size does not correspond strongly to reproductive ability in almost any species.
Normal variations
Depending on temperature, a flaccid (not erect) penis of average size can withdraw almost completely within the body. During erection the penis will return to its normal (erect) size.
Other variations:
* Pearly penile papules are raised bumps of somewhat paler colour around the base of the glans and are normal. See sidebar picture and picture at article.
* Fordyce's spots are small, raised, yellowish-white spots 1-2mm in diameter that may appear on the penis, as well as the inner surface and vermilion border of the lips of the face, and are normal.
* Sebaceous prominences are raised bumps similar to Fordyce's spots on the shaft of the penis, located at the sebaceous glands and are normal.
* Phimosis, an inability to retract the foreskin fully, is harmless in infants and pre-pubescent males, occurring in about 8 percent of boys at age 10.
Ejaculation Facts
Average volume of semen per ejaculation: 2 to 6ml
Average number of times a man will ejaculate in his lifetime: 7,200
Average total amount of lifetime ejaculate: 18 quarts
Its muscle drives nature's only known rotary-joint. The tail SCREWS, not whips. (no pun)
Average number of calories in a teaspoon of semen: 7
Average duration of orgasm: 4 seconds
Average number of sperm cells in the ejaculate of a healthy man: 40 to 600 million
Distance sperm travels to fertilize an egg: 3-4 inches or 7.5-10 centimetres
Sperm lifespan: 2.5 months from development to ejaculation
This inforamtion has been farmed from a well-known free content encyclopedia named wikipedia