physio- female reproductive system

the age that reproductive organs become functional

define puberty

the repetitive cycle that happens when there is no gestation

the period between 2 ovulations

what is the estrous cycle?

production of egg cells

production of sexual hormones- estrogens and pregesterone

what are the functions of the ovaries?

GnRH

what is 1?

LH and FSH

what are 2 and 3?

progesterone and estrogen

what are 4 and 5?

FSH and LH

what hormones from the anterior pituitary cause the release of sexual hormones (estrogens and progesterone) from the ovaries?

GnRH (gonadotropin-releasing hormone)

what hormone from the hypothalamus triggers the anterior pituitary to secrete FSH and LH?

steroid hormones

what type of hormones are progesterone and estrogen?

liposoluble- they are steroid hormones

are progesterone and estrogen hydrosoluble or liposoluble?

cholesterol

progesterone and estrogen are _______ derived

prepare the uterus for pregnancy and the breasts for lactation

what is the main role of progesterone?

aromatase

what is responsible for conversion of androgens into estrogens?

converts androgens (testosterone) to estrogens

what does aromatase do?

promote growth and proliferation of specific cells that are responsible for secondary sexual characteristics

what is the main role of estrogens?

ovaries

progesterone and estrogens are synthesized in the ______

granulosa and theca cells

what cells of the ovaries produce the hormones?

progesterone and androgens- which are then converted to estrogens by aromatase (also produced by these cells)

in the ovaries, granulosa and theca cells produce ______

convert cholesterol to progesterone and produce aromatase

what exactly do granulosa cells do?

convert cholesterol to androgens

what do theca cells do?

theca cells

what cells of the ovaries make androgens?

granulosa cells

what cells of the ovaries make progesterone and aromatase?

-ovum is surrounded by one layer or granulosa cells

-FSH stimulates early growth of primary follicle

-ovum grows with LH and FSH stimulation

-more granulosa layers are added due to FSH and LH stimulation

what is occurring during follicular growth?

granulosa cells

what ovary cells are targeted by FSH?

theca interna, androgens

LH targets ____ cells of the ovary, which produce ____

positive, a peak of LH

LH and FSH cause synthesis of progesterone and estrogens in the ovaries, and this estrogen gives ______ feedback to the anterior pituitary, causing......

the peak of LH (due to positive feedback by estrogens)

what event causes ovulation?

FSH also increases, and the 2 hormones (FSH and LH) cause the follicle to swell, LH converts granulosa and theca cells into progesterone secretors and causes final follicular growth until it breaks and releases the egg

how does the LH peak cause ovulation?

LH

which hormone allows the final follicular growth, leading to the release of the egg?

LH

a peak in ______ causes ovulation

the phase after ovulation, where the granulosa and theca cells become luteal cells. they enlarge and fill with lipids, creating the corpus luteum. granulosa cells make more progesterone and theca cells make more androgens that become estrogens

what is the luteal phase?

granulosa, progesterone

during the luteal phase, _____ cells make more ______

albicans

after the corpus luteum, it becomes the corpus _______

theca, granulosa

LH acts on ____ cells, while FSH acts on _____ cells

androgens

theca cells produce ______

aromatase and progesterone

granulosa cells produce ______

positive feedback from estrogens from the ovaries

what causes the peak of LH?

inhibin, negative, to the anterior pituitary to secrete less FSH

during ovulation, granulosa cells release ______, which sends _____ feedback to the _____

less

during the luteal phase, is more or less LH acting on the theca cells?

low LH levels

what causes the atrophy of the corpus luteum?

progesterone, estrogens, inhibin

the corpus luteum secretes....

negative, hypothalamus and anterior pituitary (to inhibit secretion of GnRH, LH, and FSH)

the inhibin from the corpus luteum sends _____ feedback to the _____

hormone production is stopped- no more release of estrogen, progesterone, inhibin

what happens when the corpus luteum dies?

now, there is no more negative feedback to the hypothalamus and anterior pituitary, so they being to release GnRH, FSH, and LH, so the cycle begins again

when the corpus luteum dies and stops releasing hormones, what does this cause?

non-primate female mammals

which animals have an estrous cycle?

period of sexual receptivity (aka heat)

what is estrus?

humans and other primates

which animals have a menstrual cycle rather than an estrous cycle?

high estrogen in the receptive period

why would there be bleeding in animals experiencing estrous cycles?

because the endometrium of the uterus is shed

-in estrous cycle, the endometrium is reabsorbed, so bleeding does not occur

why do animals with a menstrual cycle bleed?

the follicular phase

what is proestrus?

follicular phase and ovulation

what is occurring during estrus?

metestrus and diestrus

the luteal phase is separated into what 2 phases?

not a phase, but a period of no cycling between diestrus and proestrus

what is anestrus?

diestrus

at what phase is progesterone released the most?

proestrus

estrogen levels peak during what estrous phase?

24-48 hours later

ovulation occurs how long after the LH peak?

corpus luteum, progesterone

during diestrus, the ______ is producing high levels of _______

PGF2a, uterus

regression of the corpus luteum

towards the end of diestrus, if the female is not pregnant, _____ is released from the ______. this causes ______

FSH

right after ovulation, the metestrus phase is occurring, and we observe a rise in what hormone?

it is limited to a "heat" period called estrus

for animals with an estrous cycle, is sexual receptivity limited or can it occur any time?

ovulation

the "heat" period, or period of sexual receptivity, is occurring close to what part of the cycle?

high levels of estrogen

why might an estrous animal bleed?

luteal phase

during what phase is progesterone production the highest?

progesterone

what hormone gives negative feedback to the hypothalamus in relation to GnRH?

estrogen

what hormone gives positive feedback to the hypothalamus in relation to GnRH?

inhibit, which stops the negative feedback and restarts the cycle

does PGF2a stimulate or inhibit progesterone secretion?

high levels of progesterone, without pregnancy, stimulates the uterus to produce PGF2a, which inhibits progesterone, stopping the negative feedback, and restarting the cycle

what occurs to allow the cycle to restart?

PGF2a

when there is no pregnancy, ________ inhibits progesterone secretion

estrogen

during the follicular phase, there are high secretions of what hormone?

high levels of estrogen during proestrus give positive feedback to the anterior pituitary and hypothalamus, causing high levels of FSH and LH (mostly LH) to swell the follicle until is breaks and releases the egg

ovulation occurs because....

decrease

after ovulation, estrogen levels _______ (Increase or decrease)

animal is standing to be mounted, the vulva is enlarged and "winking"

what are the physical signs of estrus?

the corpus luteum regresses due to PGF2a release from uterus

what happens after ovulation if the female is not pregnant?

to begin growth of new follicles

why does FSH peak during diestrus?

metestrus

in the cow, what phase does ovulation occur (this is different than other species)?

pregnancy, lactation, disease, stress, malnutrition, etc

what are some causes of anestrus?