Yan Repro and Hormonal Functions of Male Flashcards
how many seminiferous tubules are there?
900
Are the epididymis long?
sort of, 6m long
When does puberty start?
around 12-14 years of age
What are the three phases of psermatogenesis?
1) mitotic of spermataogonia to spermatocytes
2) meiosis turning spermatocytes into spermatids
3) haploid differentiation and morphogenesis of spermatids to spermatazoa
Where do spermatagonia hang out?
on the basal membrane waiting to undergo mitosis
So you have PGCs that turn into spermatogonia and wait on the basal membrane until puberty, where they will begin to undergo mitosis to turn into (blank)
spermatocytes and then eventually become sperm
What 2 things do sperm need to be effective?
flagella and acrosome
What is the acrosome filled with?
enzymes to penetrate the shell of the egg
What three hormones stimulate spermatogenesis?
LH
FSH
Testosterone
What secretes testosterone and thus helps with the meiotic and haploid phases of spermatogenesis?
Leydig cells
What is secreted by the anterior ptituitary gland and stimulates the leydig cells to secrete testosterone?
LH
What is secreted by the anterior pituitary gland and stimulates the sertoli cells to secrete growth factors to maintain quantitiave spermatogenesis?
FSH
How do you make estrogen?
by aromatizing testosterone in Sertoli cells
What does estrogen do in men?
it allows for the reabsorption of fluid from the epididymis to allow for concentrated sperm
Beta estrogen receptors on spermatogonia, spermatocytes and sertoli cells may mediate the actions of (blank)
xenoestrogens (estrogenic endocrine disrupters; mimc estrogen)
What is secreted from sertoli cells or germ cells and can as effectors of major hormonal signals?
growth factors
Paracrine and autocrine regulation of growth hormone is under the control of (Blank)
endocrine signals
Do males need estrogen?
yes, without it they will become infertile
What binds to sertoli cells to make it produce growth factors and inhibin?
FSH
How does a sperm become motile?
it gains motility as it moves from the head (caput) of the epididymis to the tail (cauda) of the epididymis.
At what point in the epididymis does the sperm become motile?
at the middle (corpus) of epididymis (in the head the are not motile)
Where is the majority of sperm stored and are they motile here?
in the vas deferens and no, motility is suppressed here
Since sperm is not motile in the vas deferens when do they become motile again and describe this motility?
upon ejaculation they become motile and when they enter the female they swim all crazy so they can penetrate the egg.
How do the sperm start swimming all crazy in the female reproductive tract?
via ion channels
Where do sperm survive longer, the epididiymis of female reproductive tract?
epididymis can last greater than 1 month
in female reproductive tract 1-2 days
What kind of microenvironment do you need to have motile sperm?
alkaline
acidic is loss of motility
What do seminal vesicles secrete and what do they empty into?
mucoid material w/ fructose, citric acid, prostaglandins, fibrinogen, and others
empty into ejaculatory duct
What do the seminal vesicle secretions provide the sperm?
nutrition and the prostaglandins aid fertilization
What does the prostate gland do?
An acidic secretion w/ calcium, citrate ion, a clotting enzyme and profibrinolysin.
What does the prostate gland do during emission?
contract together with the vas deferens to add fluid to the semen
Why is the prostate gland secretion acidic?
to neutralize the fluid from the seminal vesicles
secretions from what make up the semen and in what quantities?
Vas deferens (10%) -> sperm and fluid Seminal vesicle (60%) Prostate gland (30%) bulbourethral glands (small amount)
What are the characteristics of sperm?
ph of 7.2-8
milk appearance
clotting enzyme (gets dissolved by profibrinolysin from the prostate gland)
How long does semen stay in the vas deferens and epididymis? How about in the female tract?
1 month
1-2 days
Can you freeze sperm?
yup for years!
What does capacitation do?
it makes sperm capable of fertilizing the egg
Where does capacitation occur and what does it do?
in the female reproductive tract
It washes off inhibitory factors (these suppressed sperm activity)
removed lipid/cholesterol vesicles and exposed acrosome to release acrosomal enzymes
Sperm membrane becomes permeable to calcium and increases sperm motility to penetrate zona pellucida
How do you make IVF work?
you wash sperm with HTF or capacitating medium
What is the acrosome reaction?
hyaluronidase and proteolytic enzymes dissolve connective tissue and zona pellucida
Where does the acrosome come for and what is it essential for?
comes from the golgi and is essential for sperm to fertilize egg
What dissolves connective tissues among multiple layers of granulosa cells?
hyaluronidase
What dissolves the zona pellucida?
proteolytic enzymes