2: Principles of Reproduction- Henry Flashcards
primary function of the testes
- hormone production (testosterone)
2. sperm production aka spermatogenesis
cells that lie between the tubules and produce testosterone
leydig cells
part of the wall of the tubules and divides the tubules into two compartments
sertoli cells
functions of the leydig cell
- testosterone synthesis
2. testosterone secretion into the blood
key functions of the sertoli cells
- support germ cells
- signal spermatogenesis
- regulate pituitary function
- produce androgen binding protein
key regulator of testosterone production in leydig cells
LH
key regulator of sertoli cell proliferation and semniferous tube growth
FSH
______ regulate pulsatile release of gonadotropins which is impacted by multiple factors
GnRH
from leydig cells, inhibits release of gonadotropins through negative feedback loop
testosterone
from sertoli cells in response to FSH inhibits release through negative feedback
inhibin B
blocks effects of inhibin B
activin
LH promotes…
- cholesterol movement from outer to inner mitochondrial membrane by steroidogenic acute regulatory protein
- conversion of cholesterol to pregnenolone
enzyme specific to gonads that converts androstenedione to testosterone
17B-hydroxysteroid dehydrogenase
converts testosterone to 17b estradiol
aromatase
which proteins are secreted testosterone bound to?
albumin
sex hormone binding globulin SHBG
androgen binding protein (from sertoli cells)
DHT =
dihydrotestosterone
conversion to DHT from testosterone allows for prolonged androgen action
epiphyseal closure, suppress osteoporosis, feedback regulation at hypothalamus
estradiol
sexual development, pubic and underarm hair development, activity of sebaceous glands
DHT
spermatogonia proliferation =_________. spermatid formation = __________.
mitosis
meiosis
maturation of spermatids =
spermiogenesis
release from sertoli cells =
spermiation
how long does spermatogenesis take?
70 days
___ and ____ are needed for complete maturation of the spermatozoa
FSH
testosterone
prinicipal reproductive organ responsible for estrogen and progesterone production as well as the storage and release of the ovum
ovaries
diploid oocyte remains arrested until….
signaled to undergo apoptosis or develop to haploid secondary oocyte
oocytes associtae with follicular cells to form the _____
follicle
follicle consists of internal granulosa cells and external thecal cells
day 1- 14 =
day 15-28 =
follicular phase (estradiol) luteal phase (estradiol and progesterone)
estradiol production is under control of
LH and FSH
rise in estradiol produces a…
low-amplitude, high-frequency LH secretion needed for follicle development
surge in estradiol also produces LH and FSH surge at mid-cycle which induces ovulation
____ promotes proliferation of the endometrial lining
estrogen
______ synthesize androstenedione in response to LH
theca cells
androstenedione is converted to ______ in granulosa cells which is controlled by _____
estradiol
FSH
ovulation is stimulated by a surge in _
LH
______ is thermogenic and produces as 0.5-0.8 degree increase in BBT
pregesterone - can be used as an indicator of ovulation
mid-cycle surge in LH induced by positive feedback of _______
high estrogen levels
rise in progesterone and estradiol is under the control of ______
LH
spike in inhibin B following ______. rise in inhibin A secretion during ______.
ovulation
luteal phase
______ promotes differentiation of endometrial cells into secretory cells
progesterone
androstenedione is converted to estradiol in the ________
luteinized granulosa cells
if implantation occurs, the corpus luteum does not regress. Instead placetal derived ________
human chorionic gonadotropin stimulates ovarian steroidogenesis
after week __, maintenance of pregnancy is not dependent on corpus luteum since the placenta can synthesize steroids
week 8
hatching =
apposition =
break down of the zona pellucida
trophoblastic cells of the balstocyst make contact with endometrium
_____- send out protrusions and invade endometrium
syncytiotrophoblasts
do maternal and fetal blood mix?
NO
