Review how hormones regulate the male reproductive system.
o Endocrine Regulation
FSH stimulates Sertoli cells of seminiferous tubules
Enhances spermatogenesis
Sertoli cells secrete inhibin
o Reduces FSH secretion
LH stimulates Leydig cells
Secrete testosterone
Negative feedback on anterior pituitary and hypothalamus
- Describe spermatogenesis.
o Spermatogenesis
Spermatogenesis
Stimulated by testosterone, enhanced by FSH
o Also stimulated by estrogen
At puberty, males have 1-2K spermatogonia (germ cells)
Spermatogonium undergoes mitosis to make primary spermatocyte
o Prevents exhaustion of spermatogonia
Primary spermatocyte (Spermatogenesis) undergoes meiosis I to
produce 2 secondary spermatocytes
Each secondary spermatocyte undergoes meiosis II to produce
Conversion of spermatids to spermatozoa (sperm) (Spermiogenesis)
o Develop acrosome
Contains digestive enzymes
o Grows midpiece
Filled with mitochondria
o Develop flagellum (axoneme)
o Sertoli cells remove cytoplasm
o DNA compacts
Spermatozoa are released into lumen of seminiferous tubules
, o Non-motile and immature
o
- Describe spermiogenesis.
o Spermiogenesis
Spermatogenesis
Stimulated by testosterone, enhanced by FSH
o Also stimulated by estrogen
At puberty, males have 1-2K spermatogonia (germ cells)
Spermatogonium undergoes mitosis to make primary spermatocyte
o Prevents exhaustion of spermatogonia
Primary spermatocyte (Spermatogenesis) undergoes meiosis I to
produce 2 secondary spermatocytes
Each secondary spermatocyte undergoes meiosis II to produce
Conversion of spermatids to spermatozoa (sperm) (Spermiogenesis)
o Develop acrosome
Contains digestive enzymes
o Grows midpiece
Filled with mitochondria
o Develop flagellum (axoneme)
o Sertoli cells remove cytoplasm
o DNA compacts