BIOL 001 Lecture Notes - Lecture 25: Androgen-Binding Protein, Hypothalamus, Sertoli Cell
6 Aug 2020
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Document Summary
Embryonic development primordial germ cells divide, differentiate into spermatogonial stem cells. Spermatogonial stem cells divide via mitosis (occurs in seminiferous fluid in the testes) Undifferentiated cells in the walls of seminiferous tubules. These cells are maintained via mitotic divisions. Some of them become primary spermatocytes (approx 3 million/day) Meiosis 1 > 2 secondary spermatocytes (n) > differentiates into mature sperm cells (n) Spermatogenesis is 1) continuous, 2) adjacent sites not necessarily synchronized, 3) takes approx 7 weeks in humans 4) wave of sperm production along tubule seminiferous wave. 3 parts: head (contains the nucleus where genetic material is, fuses with nucleus of the egg and acrosome enzymes required for fertilization) midpiece (contains mitochondria), tail (flagellum, allows sperm to move, whips back and forth) > ap releases 2 gonadotropins luteinizing hormone and follicle stimulating hormone. > leydig cells produce, secrete testosterone, other androgens. High levels in the testes required for spermatogenesis. 15-200 million sperm/ml of semen healthy.
