Updated December 18, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

The male orgasm is a complex experience. The major function of the male orgasm is the ejaculation of sperm, though not all men ejaculate with orgasm. The function of the female orgasm is less clear, although it may help to move the sperm toward the ovum (egg).

In the 1950s, Alfred Kinsey, the first scientist to study human sexuality in any detail, described the orgasm as "an explosive discharge of neuromuscular tension!" There is still a lot about the male orgasm that is not entirely understood.

Ejaculation and the Male Orgasm
As noted above, it is possible to have a male orgasm without ejaculation.

• Pre-adolescent boys may experience an orgasm without ejaculation.
• Some men do not have an ejaculation until several seconds after orgasm.
• Some men who are incapable of ejaculation are still capable of orgasm.
• Some men may experience several ejaculations and go on to have further orgasms, but without ejaculation.

Physical Experience of the Male orgasm
The male orgasm seems to have psychological as well as physical effects. Some men describe a focal experience, feeling the orgasm exclusively in the scrotum and the genital area. Other men report their orgasm as a sensation that spreads to some parts of the body. Other men state that their orgasms are felt throughout their bodies. How much of the sensation of orgasm is physical and how much psychological is difficult to judge.

What Happens During the Male Orgasm?
During intercourse, as a man nears orgasm, his pelvic thrusts become less voluntary and muscles of the penis begin to contract rhythmically in order to eject semen from the urethra.

When an orgasm begins, heart rate, blood pressure and respiration all increase.

Some Differences Between Male and Female Orgasms
Although similar in some ways, there are differences between the male and female orgasm.

• The female orgasm has the effect of sucking sperm towards the egg (the ovum) in the fallopian tube.
• Women can often experience an orgasm for a longer period of time than a man.
• In general, women are more capable of rapidly returning to orgasm following an initial orgasm.