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A spermatozoon (/ s p ər ˌ m æ t ə ˈ z oʊ. ən, ˌ s p ɜːr m ə t ə-/; [1] also spelled spermatozoön; pl.: spermatozoa; from Ancient Greek σπέρμα (spérma) 'seed' and ζῷον (zôion) 'animal') is a motile sperm cell produced by male animals relying on internal fertilization.
The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. [2] Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid ...
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 with 46 paired chromosomes. In mammals, sperm is stored in the epididymis and released through the penis in semen during ejaculation. The word sperm is derived from the Greek word σπέρμα, sperma, meaning "seed".
Sperm Spermiogenesis is the final stage of spermatogenesis , during which the spermatids develop into mature spermatozoa . At the beginning of the stage, the spermatid is a more or less circular cell containing a nucleus , Golgi apparatus , centriole and mitochondria ; by the end of the process, it has radically transformed into an elongated ...
A 1992 World Health Organization report described normal human semen as having a volume of 2 mL or greater, pH of 7.2 to 8.0, sperm concentration of 20×10 6 spermatozoa/mL or more, sperm count of 40×10 6 spermatozoa per ejaculate or more, and motility of 50% or more with forward progression (categories a and b) of 25% or more with rapid ...
Sertoli cells function to nourish the developing sperm cells. They secrete androgen-binding protein , a binding protein which increases the concentration of testosterone. There are two types: convoluted and straight, convoluted toward the lateral side, and straight as the tubule comes medially to form ducts that will exit the testis.
The spermatids are currently surrounded by Sertoli cells, which nourish the sperm and produce inhibin, an inhibitor of the follicle-stimulating hormone (FSH). [3] The last step of spermatogenesis is spermiogenesis. During this process, the spermatids are transformed into spermatozoa, mature sperm. At this point, no other division occurs.
As postmeiotic germ cells develop to mature sperm they progressively lose the ability to repair DNA damage that may then accumulate and be transmitted to the zygote and ultimately the embryo. [5] In particular, the repair of DNA double-strand breaks by the non-homologous end joining pathway, although present in round spermatids, appears to be ...