Reproductive system Flashcards
Hypothalamus releases …… which acts on ……
GnRH- Gonadotropin releasing hormone
Pituitary gland
Pituitary gland releases ….. which acts on …..
Lutenising hormone, FSH
Gonads
Gonads
Produce germ cells
Produce sex steroid hormones
Ovaries release
Oestrogens (ERs- oestrogen receptors) eg oestrone, oestradiol
Progesterone (PRs)
Testes release
Androgens: testosterone
Dihydrotestosterone (DHT) is the common form in the body
seminiferous tubules
In the testes
The site of sperm production (spermatogenesis) and hormone synthesis
2 cell types in the seminiferous tubules
Leydig- testoterone producing
Serroli- in wall of tubules where sperm are derived from
Spermatogenesis
FSH/testosterone drive production of sperm
Testosterone acts locally on serrolis, and gets into bloodstream via testicular vein
Precursors of androgens
cholesterol, pregnenolone, progesterone
Androgens effect on Hypo
decr GnRH secretion
-ve feedback
Androgen effects on Pituitary
decr LH secretion
-ve feedback
Androgens effect on metabolism
‘anabolic steroids’
Protein anabolism
Bone growth
Stimulates erythropoietin
Androgen effects on testes
spermatogenesis
Androgens effect on male sex charateristics
Differentiation of male reproductive organs
Secondary sex characteristics
Sex drive
Sertoli cells also release
Inhibin, -vely feeds back onto pituitary to inhibit production of only FSH