HROMONAL REGULATION OF REPRODUCTIVE SYSTEM Flashcards
what is the reproductive sysem
both male and female reproductive systems include a pair of gonas (testes or ovaries)
gonads are organs that produce reproductive cells (sperm in male egg in female) and sex hormones that regulate the reproductive sysem
what happens at puberty males
the hypothalamus increases the production of gonadotropin releasing hormone (gnrh)
and gnrh acts on the anterior pituitary gland to release follicle stim ormone (fsh and luteinizing hormone (lh)
what does fsh and lh in males do
fsh causes the seminferous tubules in the testes to produce sperm
lh causes the interstitial cells in the testes to release the hormone testosterone
test then acts on tissues to complete the development of the sex organs and secondary sex characteristics such as facial hair, muscle, etc
negative feedback
fsh also causes the seminiferous tubules to release the hormone inhibin which acts on the anterior pituiatary to inhibit the production of fsh
as fsh drop, the testes release less inhibin
test acts on the anterior pituitary to inhibit the release of LH
what happens at puberty in females
the hypothalamus increases the production of gnrh and gnrh targets the anterior pituitary gland
what happens during THE MENSTRUAL CYCLE
egg is release same time the uterus is most receptive to a fertilized egg and is controlled by estrogen and progesterone
composed of the ovarian cycle and uterine cycle
what happens in the ovaries
the ovvaries contain specialized cell structures called follicles.
a single egg developes within each follicle
each month, a single follicle matures and ruptures releasing the ovun into the oviduct and its called ovulation
what happens during ovarian cycle
it has two stages:
the follicular stage and luteal stage
the follicular stage begins when gnrh stims the anterior pituitary to release fsh
- AN INCREASE IN fsh secretion from the anterior pituitary stims one follicle to mature
- the maturing follicle releases estrogen and some progesterone
- estrogen acts on the anterior pituitary to inhibit fsh secretion and trigger the release of gnrh. it also maintains sex organs and secondary sex charctertistics
WHAT happens during the follicular stage
the gnrh stims the anterior pituitary to secrete lh which triggers ovulation. the follicle bursts and releases its egg
- ovulation marks the end of the follicular stage an the beginning of the luteal phase
what happens during the luteal phase
once the egg is release, lh causes the follicle to develop into a corpus luteum.
- the corpus luteum secretes progesterone and some estrogen to inihibt lh and fsh production in the anterior pituitary.
-as the corpus luteum degernerates, the progesterone and estrogen levels drop, causing increased fsh seceretion from te anterior pituitary
what happens during the uterine cycle
prepares the uterus to recieve and nurture a fertilized egg. the events cause a build up of blood vessules and tissues in the endometrium (lining of uterus)
uteruine cycle begins on day one of menstruation. the lining of uterus has degenerated and levels of progesterone and estrogen are low.
- menstruation alsts for the first 5 days of cycle and at the end, the endometrium is very thin. a new follicle is maturing during this time and releasing estrogen
on day 6, high levels of estrogen causes the endometrium tobegin to thicken
after ovulation (day 14) the release of progesterone from the corpus luteum cause the rapid thickening of the endometrium and between day 15-23 the endometrium can double or triple in thickness
if fetilization doesnt occur the corpus luteum degenerates and the level of sex hormones drop. the endometrium breaks down and menstruation begins again
the uterine cycleif ferilization occurs
the fertilized egg releases an lh like hormone called hcg which sotps the breakdown of corpus luteum. progesterone maintains the uterine lining and estrogen prevent a new follicle from maturing
travels to uterus over 7 days and plans itself in the uterine lining where THAT DAMN BABY DEVELOPS FUCK DEM KIDS
