female physiology test 3 smith

Question 1

T/F Negative feedback loops are the most common homeostatic control mechanisms?

Answer 1

true

Question 2

what are some examples of positive feedback loops?

Answer 2

oxytocin in parturition

milk production

Question 3

what is the hormone released from the hypothalmaus in the HPO loop?

Answer 3

gonadotropoin releasing hormone (GnRH)

Question 4

what are the trophic hormones of the HPO loop?

Answer 4

Follicle-stimulating Hormone (FSH)
Luteinizing Hormone (LH)

Question 5

what the target hormones of the HPO loop?

Answer 5

Estrogens
Progesterone
Inhibins (peptide hormones)

Question 6

estrogens from the theca cells feedback inhibit what?

Answer 6

GnRH, LH, and FSH secretion

Question 7

Inhibins from the granulosa cells inhibit what?

Answer 7

FSH secretion

Question 8

LH stimulates what?

Answer 8

thecal cells only

Question 9

both LH and FSH stimulate what?

Answer 9

granulosa cells

Question 10

what is the predominant estrogen during reproductive years?

Answer 10

Estradiol (E2)

Question 11

what is the predominant estrogen during menopause?

Answer 11

Estrone (E1)

Question 12

what is the predominant estrogen during pregnancy?

Answer 12

Estriol (E3)

Question 13

Functions of estrogen

Answer 13

• sexual maturation and secondary sex characteristics
• increases CNS excitability
• stimulate endometreal proliferation and uterine growth
• reduce rate of bone re-adsorption
• increase HDL and triglycerides
• decreases LDL
• Enhance blood coagulability

Question 14

estrogen is at a low point during menses, so the pituitary makes and secretes?

Answer 14

FSH and LH

Question 15

FSH and LH stimulate growth of?

Answer 15

premordial ovarian follicles

Question 16

Prior to ovulation LH, acts predominantly on the theca cells to enhance production of androgenic hormones (androstenedione and testosterone), which cross over the basement membrane of the follicle to granulosa cells which are under FSH influence to produce what?

Answer 16

estradiol

Question 17

E2 increase inhibits what?

Answer 17

FSH and LH release

Question 18

T/F building up to ovulation, FSH and LH have accumulated in anterior pitutiary gland due to high levels of estrogen that predominate follicular phase?

Answer 18

True, their release is inhibited by estrogens

Question 19

what causes the LH surge?

Answer 19

Temporary Flip to a positive feedback of estrodiol(E2) to released FSH and LH. This leads to ovulation

Question 20

how do birth control pills work?

Answer 20

release constant low levels of estrogen and progesterone which inhibit GnRH, FSH, and LH therefore the follicular cell never develops

Question 21

what is the luteal phase?

Answer 21

begins at ovulation and last 14 days.
-remaining ovarian cells become the corpus luteum and produce some E2 as well has high amounts of progesterone which predominates.

Question 22

what do high levels of progesterone and estrogens caused by the corpus leteum do?

Answer 22

inhibit the release of LH and FSH preventing a second ovulation event.

Question 23

if the egg is not fertilized and/ or doesn’t successfully implant what happens?

Answer 23

hormones decline with the degeneration of the corpus luteum to corpus albicans and the shedding of the lining of the uterus occurs
-bleeding results due to the decrease in LH levels

Question 24

what hormone dominates the follicular growth phase?

Answer 24

estrogen

Question 25

what hormone dominates the luteal (ovulation) phase?

Answer 25

progesterone

Question 26

what is the most important progestin?

Answer 26

progesterone

Question 27

why is progesterone so important?

Answer 27

all steroid hormones are derived from cholesterol, progesterones serve as a precursor to synthesis of all estrogens, androgens, and adrenocortical steroids.

Question 28

physiological effects of progesterone

Answer 28

``` preps uterus for implantation secretory mechanism of the breast increases fat deposition decrease CNS excitability increases body temp decreases PC02 during pregnancy(improves oxygenation of fetus) ```

Question 29

describe the childhood changes in women

Answer 29

a critical body weight must be reached for puberty to occur. This is due to lepitin. If leptin levels are adequate, the hypothalamus becomes less sensitive to estrogen and GnRH begins, which triggers FSH and LH, thus increasing ovarian release of estrogens

Question 30

describe the changes at puberty

Answer 30

increase estrogen secretion contribute to bone growth, breast development, pubic hair and menarche.

Question 31

what is menarche

Answer 31

the first menses and the start of endometrial cycle during puberty of women

Question 32

why does ovulation not usually begin with menarche?

Answer 32

levels of FSH and LH continue to rise and then an adult cyclical ovarian pattern usually achieved 2-4 years post-menarche.

Question 33

perimenopause

Answer 33

1-10 years preceding onset of menopause large fluctuation of gonadotropins and estradiol levels are observed due to the loss of inhibins (loss of inhibition of FSH)

Question 34

menopause

Answer 34

permanent cessation of menstruation due to loss of ovarian follicular actvitiy - FSH levels are usually elevated - Estrone (E1) dominant due to testosterone converted by aromatase in adiopocytes - ovaries no longer secret progesterone and estradiol.

Question 35

upon implantation trophoblast cells begin to secrete what?

Answer 35

human chorionic gonadotropin (hCG)

Question 36

why is hCG important

Answer 36

it bypasses the HPO axis control and prompts the corpus luteum to continue expressing estrogens and progesterone preventing menstruation

Question 37

at 8 weeks what is producing progesterone and estrogen?

Answer 37

the placenta because the corpus luteum degenerates and ovaries become inactive until after child birth

Question 38

what happens is hCG levels are inadequate?

Answer 38

spontaneous abortion

Question 39

T/F maternal urine estriol excretion can be monitored as an index of the fetus condition?

Answer 39

True, the principal estrogen formed during pregnancy is estriol (E3)

Question 40

what are the hormones involved in parturition?

Answer 40

- estrogen: induces uterine oxytocin receptor - oxytocin: causues contractions in a positive feedback mechanism - relaxin: peptide hormone secreted by the placenta to relax the cervix and pelvic ligaments to ease birth.

Question 41

why is prolactin said to be under predominant inhibitory control?

Answer 41

- prolactin inhibitory factor (PIF) aka dopamine is always produced by hypothalamus - only when prolactin is needed (pregnancy and lactation) does the hypothalamus stop production allowing the anterior pituitary to secrete prolactin.

Question 42

what causes milk ejection due to suckling of the breast?

Answer 42

oxytocin | **positive feedback

Question 43

what is the first fluid called that comes out of the breast?

Answer 43

``` colostrum. easy to digest high in carbs, protein, and antibodies low in fat laxative effect ```