Flashcards in Lecture 07: Spermatogenesis (Pozor) Deck (23)
formation of spermatozoa from spermatogonia (proliferation)
mitotic divisions involving proliferation and maintenance of spermatogonia
meiosis in spermatogenesis
reduction of genetic material. Involves primary and secondary spermatocytes
morphologic transformation of spherical spermatids into spermatozoa (differentiation)
# chromosomes/chromatids in primary and secondary spermatocytes, spermatids, and spermatozoa?
secondary: 1n, 2C (because meiosis I has occured)
spermatids: 1n, 1c (because meiosis II has occured)
spermatozoa: 1n, 1c
role of centrioles in spermatogenesis
well organized tubules that move toward nuclear pole and help form tail and system of attachment for tail in sperm
4 phases of spermiogenesis
Golgi phase of spermiogenesis
1st phase. formation of acrosomic granule
Cap phase of spermiogenesis
2nd phase. growth of acrosomic head cap
Acrosomal phase of spermiogenesis
3rd phase. condensation, elongation, shaping of sperm
Maturation phase of spermiogenesis
4th and final phase. final formation of flagellum and neck piece, final condensation and shaping of nucleus
Where is estrogen produced in the male?
tail of epididymis
Importance of disulfide crosslinking in spermatogenesis
allows DNA to be densely packed into sperm heads
What do sertoli cells produce?
inhibin and activin
what do leydig cells?
Main hormone involved in spermatogenesis (especially to initiate it) ******
what inhibits FSH?
What does LH do in spermatogenesis?
stimulate leydig cells to produce testosterone
Role of FSH in spermatogenesis
acts on sertoli cells, causing them to release estrogen, DHT, inhibin
Which hormones have negative feedback to AP during spermatogenesis?
What does endpiece of sperm's tail lack?
axoneme (cytoskeletal core) and fibrous sheath
Sperm tail organization
9+2 axoneme (central unpaired doublet surrounded by 9 paired doublets of microtubules arranged like spokes on a wheel)