Christian676 2010-05-15 15:57:25

The penis (plural penises, penes) is an external sexual organ of certain biologically male organisms, in both vertebrates and invertebrates.

The penis is a reproductive organ, technically an intromittent organ, and for placental mammals, additionally serves as the external organ of urination. The penis is generally found on mammals and reptiles.

The word "penis" is taken from the Latin word for "tail." Some derive that from Indo-European *pesnis, and the Greek word %u03C0%u03B5%u03BF%u03C2 = "penis" from Indo-European *pesos. Prior to the adoption of the Latin word in English the penis was referred to as a "yard". The Oxford English Dictionary cites an example of the word yard used in this sense from 1379, and notes that in his Physical Dictionary of 1684, Steven Blankaart defined the word penis as "the Yard, made up of two nervous Bodies, the Channel, Nut, Skin, and Fore-skin, etc."

The Latin word "phallus" (from Greek %u03C6%u03B1%u03BB%u03BB%u03BF%u03C2) is sometimes used to describe the penis, although "phallus" originally was used to describe images, pictorial or carved, of the penis.

The adjectival form of the word penis is penile. This adjective is commonly used in describing the male copulatory organ's various accessory structures that are commonly found in many kinds of invertebrate animals.

As with nearly any aspect of the human body that is involved in sexual or excretory functions, the word penis is considered funny from a juvenile perspective, and there are many slang words and euphemisms for the penis.

Root of the penis (Radix): It is the attached part, consisting of the Bulb of penis in the middle and the Crus of penis, one on either side of the bulb. It lies within the superficial perineal pouch.
Body of the penis (Corpus): It has two surfaces: dorsal (posterosuperior in the erect penis), and ventral or urethral (facing downwards and backwards in the flaccid penis). The ventral surface is marked by a median raphe.

The human penis is made up of three columns of tissue: two corpora cavernosa lie next to each other on the dorsal side and one corpus spongiosum lies between them on the ventral side.

The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis, which 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 frenum (or frenulum).

The urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus (pronounced /mi%u02D0%u02C8e%u026At%u0259s/), lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen. Sperm are 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 underside of the penis, running from the meatus (opening of the urethra) across the scrotum to the perineum (area between scrotum and anus).

The human penis differs from those of most other mammals, as it has no baculum, or erectile bone, and instead relies entirely on engorgement with blood to reach its erect state. It cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass.

On entering puberty, the penis, scrotum and testicles will begin to develop. During the process, pubic hair grows above and around the penis. A large-scale study assessing penis size in thousands of 17-19 year old males found no difference in average penis size between 17 year olds and 19 year olds. From this, it can be concluded that penile growth is typically complete not later than age 17, and possibly earlier.

In short, this is a known list of sex organs that evolve from the same tissue in females and males.

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; the scrotum, homologous to the labia minora and labia majora; and the foreskin, homologous to the clitoral hood. The raphe does not exist in females, because there, the two halves are not connected.

An erection is the stiffening and rising (see Erection Angle) of the penis, which occurs during sexual arousal, 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 than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.

Erection facilitates sexual intercourse though it is not essential for various other sexual activities.

Although many erect penises point upwards, it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards or even horizontally straight forward, all depending on the tension of the suspensory ligament that holds it in position. The following table shows how common various erection angles are for a standing male. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common.

Ejaculation is the ejecting of semen from the penis, and is usually accompanied by orgasm. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis (and into the vagina, if for reproductive intention via sexual intercourse). It is usually the result of sexual stimulation, which may include prostate stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep (a nocturnal emission or wet dream). Anejaculation is the condition of being unable to ejaculate.

Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerves S2-4 via the pudendal nerve. A refractory period succeeds the ejaculation, and sexual stimulation precedes it.

Pearly penile papules are raised bumps of somewhat paler color around the base of the glans and are normal.
Fordyce's spots are small, raised, yellowish-white spots 1-2 mm in diameter that may appear on the penis.
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 is an inability to retract the foreskin fully, is harmless in infancy and pre-pubescence, occurring in about 8% of boys at age 10. According to the British Medical Association, treatment (steroid cream, manual stretching) does not need to be considered until age 19.
Curvature: few penises are completely straight, with curves commonly seen in all directions (up, down, left, right). Sometimes the curve is very prominent but it rarely inhibits sexual intercourse. Curvature as great as 30° is considered normal and medical treatment is rarely considered unless the angle exceeds 45°. Changes to the curvature of a penis may be caused by Peyronie's disease.

Aillebeta 2010-05-17 00:53:55

good vid but low quality

Irvingthebee 2010-05-18 20:33:24

Christian676 where do you get your facts?

Aillebeta 2010-05-21 19:56:53

check out my post

Christian676 2010-05-21 20:33:24

lol InsaneScaryMovieGuy is such a dumb wigger. Go wear cum on your face loser.

Christian676 2010-05-22 01:11:01

Alright class next lesson is the rectum...

Christian676 2010-05-22 01:14:58

The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long. Its caliber is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. The rectum intestinum acts as a temporary storage site for feces. As the rectal walls expand due to the materials filling it from within, stretch receptors from the nervous system located in the rectal walls stimulate the desire to defecate. If the urge is not acted upon, the material in the rectum is often returned to the colon where more water is absorbed. If defecation is delayed for a prolonged period, constipation and hardened feces results.

When the rectum becomes full, the increase in intrarectal pressure forces the walls of the anal canal apart, allowing the fecal matter to enter the canal. The rectum shortens as material is forced into the anal canal and peristaltic waves propel the feces out of the rectum. The internal and external sphincter allow the feces to be passed by muscles pulling the anus up over the exiting feces. For the diagnosis of certain ailments, a rectal exam may be done.

Suppositories may be inserted into the rectum as a route of administration for medicine.

The endoscopic procedures colonoscopy and sigmoidoscopy are performed to diagnose diseases such as cancer.

Digital Rectal Stimulation, the insertion of one finger into the rectum, is used to induce peristalsis in patients whose own peristaltic reflex is inadequate to fully empty the rectum.

Manual Evacuation is the use of a gloved finger to evacuate faeces from the rectum, and is utilised primarily in acute constipation and also the long-term management of neurogenic bowel, seen most frequently in people with a spinal cord injury or multiple sclerosis. Body temperature can also be taken in the rectum. Rectal temperature can be taken by inserting a medical thermometer not more than 25 mm (1 inch) into the rectum via the anus. A mercury thermometer should be inserted for 3 to 5 minutes; a digital thermometer should remain inserted until it beeps. Due to recent concerns related to mercury poisoning, the use of mercury thermometers is outlawed. Normal rectal temperature generally ranges from 36 to 38 °C (97.6 to 100.4 °F) and is about 0.5 °C (1 °F) above oral (mouth) temperature and about 1 °C (2 °F) above axilla (armpit) temperature.[citation needed]

Many pediatricians recommend that parents take infants' and toddlers' temperature in the rectum for two reasons:

Rectal temperature is the closest to core body temperature and in young children, accuracy is critical.
Younger children are unable to cooperate when having their temperature taken by mouth (oral), which is recommended for children ages 6 and above as well as adults.
In recent years, the introduction of tympanic (ear) thermometers and changing attitudes on privacy and modesty have led some parents and doctors to discontinue taking rectal temperatures. Due to the proximity of the anterior wall of the rectum to the vagina in females or to the prostate in males and the shared nerves thereof, rectal stimulation or penetration can result in sexual arousal.

Christian676 2010-05-22 01:26:36

The vagina (from Latin vag%u012Dna, literally "sheath" or "scabbard") is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the oviduct. The Latinate plural (rarely used in English) is vaginae.

The word vagina is quite often incorrectly used to refer to the vulva or female genitals generally; strictly speaking, the vagina is a specific internal structure.

The human vagina is an elastic muscular canal that extends from the cervix to the vulva. Although there is wide anatomical variation, the length of the unaroused vagina is approximately 6 to 7.5 cm (2.5 to 3 in) across the anterior wall (front), and 9 cm (3.5 in) long across the posterior wall (rear). During sexual arousal the vagina expands in both length and width. Its elasticity allows it to stretch during sexual intercourse and during birth to offspring. The vagina connects the superficial vulva to the cervix of the deep uterus.

If the woman stands upright, the vaginal tube points in an upward-backward direction and forms an angle of slightly more than 45 degrees with the uterus. The vaginal opening is at the caudal end of the vulva, behind the opening of the urethra. The upper one-fourth of the vagina is separated from the rectum by the rectouterine pouch. Above the vagina is the Mons pubis. The vagina, along with the inside of the vulva, is reddish pink in color, as with most healthy internal mucous membranes in mammals. A series of ridges produced by folding of the wall of the outer third of the female vagina is called vaginal rugae. They are transverse epithelial ridges and their function is to provide the vagina with increased surface area for extension and stretching. Vaginal lubrication is provided by the Bartholin's glands near the vaginal opening and the cervix. The membrane of the vaginal wall also produces moisture, although it does not contain any glands. Before and during ovulation, the cervix's mucus glands secretes different variations of mucus, which provides a favorable alkaline environment in the vaginal canal to maximize the chance of survival for sperm.

The hymen is a thin membrane of connective tissue which is situated at the opening of the vagina. As with many female animals, the hymen covers the opening of the vagina from birth until it is ruptured during sexual or non-sexual activity. The tissue may be ruptured by vaginal penetration, a pelvic examination, injury, or sports. The absence of a hymen does not indicate prior sexual activity, as it is not always ruptured during sexual intercourse. Similarly, the presence does not indicate a lack of prior sexual activity, as it is possible for light activity to not rupture it, or for it to be surgically restored.

The vagina provides a path for menstrual blood and tissue to leave the body. In industrial societies, tampons, menstrual cups and sanitary napkins may be used to absorb or capture these fluids.

The concentration of the nerve endings that lie close to the entrance of a woman's vagina can provide pleasurable sensation during sexual activity, when stimulated in a way that the particular woman enjoys. During sexual arousal, and particularly the stimulation of the clitoris, the walls of the vagina self-lubricate. This reduces friction that can be caused as a result of various sexual activities. Research has found that portions of the clitoris extend into the vulva and vagina.

With arousal, the vagina lengthens rapidly to an average of about 4 in.(10 cm), but can continue to lengthen in response to pressure. As the woman becomes fully aroused, the vagina tents (last ²%u2044%u2083) expands in length and width, while the cervix retracts. The walls of the vagina are composed of soft elastic folds of mucous membrane skin which stretch or contract (with support from pelvic muscles) to the size of the inserted penis or other object.

An erogenous zone referred to commonly as the G-spot is located at the anterior wall of the vagina, about five centimeters in from the entrance. Some women experience intense pleasure if the G-spot is stimulated appropriately during sexual activity. A G-Spot orgasm may be responsible for female ejaculation, leading some doctors and researchers to believe that G-spot pleasure comes from the Skene's glands, a female homologue of the prostate, rather than any particular spot on the vaginal wall. Some researchers deny the existence of the G-spot.

During childbirth, the vagina provides the channel to deliver the baby from the uterus to its independent life outside the body of the mother. During birth, the vagina is often referred to as the birth canal. The vagina is remarkably elastic and stretches to many times its normal diameter during vaginal birth.

The vagina is self-cleansing and therefore usually needs no special treatment. Doctors generally discourage the practice of douching. Since a healthy vagina is colonized by a mutually symbiotic flora of microorganisms that protect its host from disease-causing microbes, any attempt to upset this balance may cause many undesirable outcomes, including but not limited to abnormal discharge and yeast infection. The acidity of a healthy vagina is due to lactic acid secreted by symbiotic microorganisms which retards the growth of many strains of dangerous microbes.

The vagina is examined during gynecological exams, often using a speculum, which holds the vagina open for visual inspection of the cervix or taking of samples.

Vaginismus, not to be confused with Vaginitis, refers to an involuntary tightening of the vagina, due to a conditioned reflex of the muscles in the area. It can affect any form of vaginal penetration, including sexual intercourse, insertion of tampons, and the penetration involved in gynecological examinations. Various psychological and physical treatments are possible to help alleviate it.

Vaginal diseases present with lumps, discharge and sores:

Lumps
The presence of unusual lumps in the wall or base of the vagina is always abnormal. The most common of these is Bartholin's cyst. The cyst, which can feel like a pea, is formed by a blockage in glands which normally supply the opening of the vagina. This condition is easily treated with minor surgery or silver nitrate. Other less common causes of small lumps or vesicles are herpes simplex. They are usually multiple and very painful with a clear fluid leaving a crust. They may be associated with generalized swelling and are very tender. Lumps associated with cancer of the vaginal wall are very rare and the average age of onset is seventy years. The most common form is squamous cell carcinoma, then cancer of the glands or adenocarcinoma and finally, and even more rarely, melanoma.

Discharge
The great majority of vaginal discharges are normal or physiological and include blood or menses (from the uterus), the most common, and clear fluid either as a result of sexual arousal or secretions from the cervix. Other non infective causes include dermatitis, discharge from foreign bodies such as retained tampons or foreign bodies inserted by curious female children into their own vaginas. Non-sexually transmitted discharges occur from bacterial vaginosis and thrush or candidiasis. The final group of discharges include sexually transmitted diseases, gonorrhoea, chlamydia and trichomonas. The discharge from thrush is slightly pungent and white, that from Trichomonas more foul and greenish and that from foreign bodies resembles the discharge of gonorrhoea, greyish or yellow and purulent (like pus).

tcholloventura 2010-05-25 23:57:13

The Butterfly Effect is a great movie. =D

But if you want another amazing story like that, check this classic:
<a href="http://en.wikipedia.org/wiki/A_Sound_of_Thunder">http://en.wikipedia.org/wiki/A_Sound_
of_Thunder</a>