Hellkatz: Male Reproductive Physiology Flashcards
What is spermatogenesis?
production of mature haploid spermatozoa from spermatogonial sperm cells
What’s unique about male germ cells?
Capable of producing cells that undergo mitosis
Able to produce germ cells that differentiate into spermatozoa throughout life.
When do mitosis and meiosis occur in spermatogenesis?
Mitosis begins in the embryo
Mitosis and meiosis occurs through adult life
Where does spermatogenesis occur?
seminiferous tubules of testes
What’s a spermatogenic wave?
time it takes for reappearance of same stage w/in given segment of seminiferous tubule
*spermatogenesis is staggered throughout hte seminiferous tubule so ALL developmental phases occur at one time
What is the purpose of spmeratogenic waves?
ensures that spermatozoa are produced continuously & mature sperm are always available
How long is the total spermatogenesis cycle?
64 days
How many sperm are produced daily?
100 milion
What influences spermatogenesis?
directly proportional to testosterone levels
*decreases in older age goups
What regulates testosterone secretion?
NFB from testosterone and inhibin
Produces testosterone
testicle
produces DHT
prostate
produces dihydrioepiandrostendione
adrenal
Where are SHBG made and what do they do?
made in liver and sertoli cells, bind androgens and estrogens
What steroid receptor acts as a TF?
Androgen Receptor
What nourishes developing sperm and secretes androgen binding protein and inhibin?
sertoli cells
What stimulates sertoli cells leading to sperm proliferation and differentiation?
Testosterone and FSH
What does inhibin do?
inhibits FSH from AP
What promotes muscle building, bone growth and Na and water retention?
androgens
What is andropause?
androgen def w/ aging
Aging> decreased testosterone> decreased muscle mass and increased abdominal fat
What happens to testicular function w/ andropause?
loss of spermatocytes, Leydig cells, Sertoli cells
decrease of testosterone production
compensatory increases in secretion of GnRH and gonadotropins (FSH and LH)