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Spermatogenesis, the process for producing spermatozoa, takes place in the seminiferous tubules. During spermatogenesis, the DNA of spermatogenic cells in the seminiferous tubules is subject to damage from such sources as reactive oxygen species. [1] The genomic integrity of spermatogenic cells is protected by DNA repair processes. [2]
Because its main function is to nourish developing sperm cells through the stages of spermatogenesis, the Sertoli cell has also been called the "mother" or "nurse" cell. [10] Sertoli cells also act as phagocytes, consuming the residual cytoplasm during spermatogenesis. Translocation of cells from the basal lamina to the lumen of the ...
Normal spermatogenesis, testis biopsy. High-power view of a seminiferous tubule with normal spermatogenesis. Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the mitotic division of the stem cells located close to the basement membrane of ...
The onset of puberty is controlled by two major hormones: FSH initiates spermatogenesis and LH signals the release of testosterone, [19] an androgen that exerts both endocrine activity and intratesticular activity on spermatogenesis. LH is released from the pituitary gland, and is controlled by pulses of gonadotropin-releasing hormone.
An average adult testicle measures up to 5 cm × 2 cm × 3 cm (2 in × 3 ⁄ 4 in × 1 + 1 ⁄ 4 in). The Tanner scale , which is used to assess the maturity of the male genitalia, assigns a maturity stage to the calculated volume ranging from stage I, a volume of less than 1.5 cm 3 ; to stage V, a volume greater than 20 cm 3 .
The testicles are two gonads that produce sperm by meiotic division of germ cells within the seminiferous tubules, [1] and synthesize and secrete androgens that regulate the male reproductive functions. The site of production of androgens is the Leydig cells that are located in the interstitium between seminiferous tubules. [1]
Spermatogonia going through mitosis to form primary spermatocytes in Grasshopper testes. Spermatocytogenesis. At puberty, spermatogonia located along the walls of the seminiferous tubules within the testis will be initiated and start to divide mitotically, forming two types of A cells that contain an oval shaped nucleus with a nucleolus attached to the nuclear envelope; one is dark (Ad) and ...
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.