the male Flashcards
(31 cards)
what is the role of the epididymis
sperm maturation
what is the role of the seminiferous tubules
sperm production
what is the purpose of the myoid cells that surround the seminiferous tubules
they provide a squeezing action that helps to move sperm
what cells are in the spaces between the seminiferous tubules
leydig cells
where does the biosynthesis of testosterone occur
in leading cells
where does the conversion of testosterone to dihydrotestosterone take place
in the Sertoli cells in the seminiferous tubules
how are steroid receptors transcription factors
steroid receptors have 2 binding sites one for the steroid and one for dna. blinding of the steroidal ligand acetic on the dna and alters the genes being expressed by target cells
where are androgen receptors expressed
epididymis, accessory glands, tissues where 2ndary characteristics appear
where is GnRH stored
hypothalamus
where is FSH and LH stored
anterior pituitary
how is GnRH released
pulsate release at a constant frequency
where is the FSH receptor located
on the Sertoli cell
where is the LH receptor located
on the leydig cell
how does FSH contribute to spermatogenesis, sperm maturation and hyoid cell contractility
androgen binding protein binds to T and DHT and concentrates them in the luminal fluids which stimulates the above
what enzyme converts T to DHT
5 alpha reductase
by what mechanism is GnRH secretion and LH and FSH inhibited
negative feedback with testosterone and inhibin
where is the sperms initial ability to swim
in the epididymis
what is the average vol of ejaculate
1.5-5ml
what is the average sperm count
40-250mil/ml
what percent of sperm are still motile 1h after ejculation
70%
what percent of sperm are still motile 3h after ejac
60%
ph of sperm
7.2-7.8
what makes up most of the ejaculate volume
seminal vesicle secretion (46-80%)
what is an erection
erectile tissue becoming engorged with blood
