Medical research

Endocannabinoid system may be involved in human testis physiology

The endocannabinoid system (ECS) may be directly involved in the regulation of the physiology of the human testis, including the development of sperm cells, according to a study in tissue samples from 15 patients published ...

Obstetrics & gynaecology

Large meta-analysis links IVF to higher gestational diabetes risk

Women who give birth to singleton babies following assisted reproductive technologies including vitro fertilisation (IVF) are at greater risk of developing gestational diabetes than those who conceive naturally, according ...

Medical research

Identification of all types of germ cells tumors

Germ cell tumors constitute a diverse group of rare tumors, which occur in the testes, ovaries and also in other places. Some germ cell tumors exist prenatally, while others present during or after puberty. The majority are ...

Obstetrics & gynaecology

Baby hope for unsuccessful IVF couples

A new study looking at conception rates after couples have gone through IVF treatment could offer hope to those for whom the process was unsuccessful.

Obstetrics & gynaecology

Paternal age over 51 years reduces success rate in IVF and ICSI

While female fertility comes to an irrevocable end with the menopause (at a consistently average age of 51 years), men are not constrained by similar biological senescence. Studies have shown that sperm counts may decline ...

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Sperm

The term sperm is derived from the Greek word (σπέρμα) sperma (meaning "seed") and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. A uniflagellar sperm cell that is motile is referred to as a spermatozoon, whereas a non-motile sperm cell is referred to as a spermatium. Sperm cells cannot divide and have a limited life span, but after fusion with egg cells during fertilization, a totipotent zygote is formed with the potential to develop into a new organism.

The spermatozoa of animals are produced through spermatogenesis inside the male gonads (testicles) via meiotic division. They are carried out of the male body in a fluid known as semen. Mammalian sperm cells can live for up to 3 days inside the female reproductive system.[citation needed]

Sperm cells in algal and many plant gametophytes are produced in male gametangia (antheridia) via mitotic division. In flowering plants, sperm nuclei are produced inside pollen.

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