Semen

thumb|right|287px|spermatozoon|Spermatozoa, in this case human, are a primary component of normal semen, and the agents of fertilization of female ova.

Ejaculation is the discharge of semen (the ejaculate; normally containing sperm) from the penis through the urethra. It is the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. After forming an erection, many men emit pre-ejaculatory fluid during stimulation prior to ejaculating. Ejaculation involves involuntary contractions of the pelvic floor and is normally linked with orgasm. It is a normal part of male human sexual development.

pregnancy through in vivo fertilization

Sperm (: sperm or sperms) is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Sperm cells contribute approximately half of the nuclear genetic information to the diploid offspring (excluding, in most cases, mitochondrial DNA). Animals produce motile sperm with a tail known as a flagellum, which are known as spermatozoa, while some red algae and fungi produce non-motile sperm cells, known as spermatia. Flowering plants contain non-motile sperm inside pollen, while some more ba

thumb|Pre-ejaculate on the Glans penis|glans of the penis

process of donating sperm for reproduction

thumb|Collecting Chinook salmon milt at a [[USFWS hatchery]]

analysis that evaluates certain characteristics of a male's semen

in vitro fertilization procedure

Insemination is the introduction of sperm (in semen) into a female's reproductive system in order to fertilize the ovum through sexual reproduction. The sperm enters into the uterus of a mammal or the oviduct of an oviparous (egg-laying) animal. Female humans and other mammals are inseminated during sexual intercourse or copulation, but can also be inseminated by artificial insemination.

any process that contributes to the success of sperm fertilization in multiply-mated females.

In medicine, hyperspermia is a condition characterized by an abnormally large amount of semen or ejaculate volume. It is typically defined as an ejaculate volume exceeding 5.5 mL. Hyperspermia is the opposite of hypospermia, which refers to a semen volume of less than 1.5 mL.

Surgical procedure

measure of male fertility

procedure to preserve sperm cells

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for artificial insemination, or medical study (usually in fertility clinics)

means of choosing what type of sperm cell (X-chromosome or Y-chromosome) is to fertilize the egg cell

separation of individual sperm from semen

procedure in which spermatozoa are extracted from a legally dead person