LIFESCI 2 Lecture Notes - Lecture 25: Secondary Sex Characteristic, Sertoli Cell, Leydig Cell

• School: UCLA
• Department: Life Sciences
• Course: LIFESCI 2
• Professor: Arnold, A.P., Esdin, J.

Document Summary

Testis: where sperm formed, stored & mature in epididymis. Sperm travels in vas deferens scortum out side of body, bag carrying testis & epidydimis sperm goes thru urethra during ejaculation spermatogenesis. Occurs in the seminiferous tubule of the testes. Network of close tight junctions in blood testis barrier prevents unwanted material from reaching sperm cells. Primary spermatocytes ready for meiosis (start upon hormone signal) Entire process in epididymis tail: microtubules ensure motility. Acrosome has enzyme to penetrate membrane of egg hypothalamus release gnrh -> bind to receptors on cells of anterior pituitary -> fsh & lh -> target organ testis. Fsh acts on sertoli cells, lh acts on leydig cells. Leydig cells release testosterone -> act on sertoli cells, trigger spermatogenesis. Enough testosterone -> pituitary & hypothalamus shut down releasing. Sertoli cells release inhibin -> acts specifically on fsh secreting cells. Starts working on reproductive development when still a fetus. Development and maintenance of secondary sexual characteristics.