Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
|
before puberty hormone levels |
E, P, LH, FSH all low |
|
|
after puberty but before menopause hormone levels |
E, P, LH, FSH all normal; cyclic changes |
|
|
after menopause hormone levels |
E and P low; LH and FSH high |
|
|
what part of the hypothalamic-pit-ovarian axis is the limiting factor that determines the timing of puberty |
hypothalamus (GnRH) |
|
|
the adolescent growth spurt |
earlier in females and estrogen causes the growth plates to close 2 yrs earlier than males (estrogen will eventually causes theirs to close too) |
|
|
sequence of pubertal events- thelarche |
occurs first; development of the breast; most of the breast tissue is fat; mammary gland develop primarily under the influence of estrogen |
|
|
sequence of pubertal events- pubarche |
occurs second; pubic and axillary hair growth in girls due to increase in adrenal androgens; occurs between 8-15 yrs of age; result of adrenal androgen secretion; temporary coincident with puberty but probably not causal |
|
|
sequence of pubertal events- menarche |
occurs third; first menstrual period in girls; occurs in mid to late puberty; menarche has decreased during the last century, primarily as a result of better health and nutrition; most of the early cycles are anovulatory |
|
|
delayed puberty in girls |
defined clinically as the lack of development of secondary sex characteristics in a 13-14 yr old girl; delayed puberty can occur due to trauma, genetics, or idiopathic circumstances |
|
|
precocious puberty |
breasts or pubic hair before age 7 in white girls and before age 6 in black girls; idiopathic; often this is the only unusual event in an otherwise normal reproductive life |
|
|
LH and estradial during puberty |
LH pulses increase in frequency and height during the night and estradiol increases in height during the night (estrogen doesn't pulse) |
|
|
LH and estradiol as an adult |
LH pulses consistent; estradiol is cyclic |
|
|
cellular actions of LH and FSH |
both bind to G protein coupled (cell surface) receptors which require second messengers; signal transduction is through cAMP pathway; FSH primarily stimulates aromatase; LH stimulates StAR (steroidogenic acute regulatory) protein - facilitates transport of cholesterol from the outer to the inner mitochondrial membrane, P450 side chain cleavage enzyme is on the inner mitochondrial membrane |
|
|
feedback regulation of LH/FSH secretion- positive feedback |
preovulatory levels of estradiol signal the hypothalamus/pit that the follicle is mature; this stimulates the massive preovulatory surge of LH/FSH- preovulatory secretion of progesterone enhances LH/FSH release |
|
|
feedback regulation of LH/FSH secretion- negative feedback |
estradiol/progesterone inhibit the secretion of LH/FSH- estradiol decreases the amplitude of GnRH driven LH pulses (brain/pit), progesterone decreases the frequency of LH pulses (action on the brain), negative feedback is present throughout the menstrual cycle and this is the basis for birth control pills (usually a combo of E and P) |
|
|
effects of preovulatory LH peak |
causes ovulation- unknown mechanism, prostagandins, enzymes, steroids; luteinizes the follicle- forms CL, progesterone is the primary steroid produced; resumption of meiosis in oocyte; stimulates blood flow to ovary - 90% to CL |
|
|
ovulation |
the preovulatory LH peak is causes by the late follicular phase rise in estradiol levels; there is a preovulatory peak in both LH and FSH; LH causes ovulation and leuteinization of the granulosa cells; there is an abrupt fall in estrogen and an abrupt rise in progesterone in response to LH surge- granulosa cells acquire LH receptors and the ability to make progesterone and loose aromatase enzyme |
|
|
estrogens- site of production, what is it bound to in blood, where is it inactivates |
follicle is primary site of production; bound to SHBG (TeBG) and albumin in blood; liver is primary site of inactivation |
|
|
pregestines- site of production, what is it bound to in the blood, where is it inactivated |
CL is primary site of production; bound to CBG (corticosteroid-binding globulin) in blood; liver is primary site of inactivation |
|
|
physiologic actions of estrogen at puberty, during menstruation, and in the breast/mammary gland |
puberty- growth and development of reproductive tract and secondary sex traits; menstruation- effects on uterus- increased endometrial thickness (proliferative phase), increased blood flow (spiral arteries), and increases contraction of myometrium (oxytocin); breast/mammary gland- development of the ductal system and growth and development of the nipple and areola |
|
|
physiologic actions of P |
requires E2 priming (P receptors); affects functional aspects of reproductive tract during luteal phase- endometrium becomes secretory (secretory phase), myometrium decreases contractility, nourishment of the blastocyst (uterine milk), CL demise results in fall in progesterone and the uterine lining is shed (menstruation), first menstrual period is menarche, the hallmark sign for puberty |
|
|
thermogenic activity of progesterone |
during the luteal phase, basal body temp is higher than during the follicular phase, this temp change can be followed to monitor ovulation and CL function, progesterone also affects the CNS; anesthesia, increased dreaming |
|
|
inhibin, activin - produced by and action |
produced by both the follicle and CL; most important gonadal regulators of FSH secretion |
|
|
relaxin- produced by and action |
produced by CL in luteal phase; relaxes the myometrium and possibly the pubic ligaments at parturition (role in humans is not known) |
|
|
the fallopian tube during fertilization |
sperm undergo capacitation (the ability to fertilize the ovum) in the fallopian tube; embryo remains in the fallopian tube for 3 days before it is transported to the uterus as a blastocyst; under the influence of increasing progesterone levels, contractions of the fallopian tube propel the embryo back towards the uterus; the isthmus portion of the tube relaxes to allow the embryo passage to the uterus |
|
|
fertilization event |
acrosome reaction releases hydrolytic enzymes that help sperm reach the surface of the egg; a sperm penetrates the cumulus mass, undergoes the acrosome reaction (to release hydrolytic digestive enzymes)(this is triggered by an increases in intracellular Ca2+), penetrates the ZP, and enters the ovum (the plasma membrane of the sperm fuses with that of the ovum, opening up cytoplasmic continuity); the male pronucleus subsequently fuses with the female pronucleus and the first mitotic division of the new individual occurs; the first sperm to enter also increases the Ca2+ inside the egg and causes the ZP to become rigid again (block to polyspermy) |
|
|
epigenetics |
DNA methylation, histone modifications, chromatin remodeling, and interfering RNA (RNAi) that change the phenotype of a cell without altering its DNA |
|
|
implantation |
the blastocyst and the uterus need to be synchronized for successful implantation; the blastocyst (embryo) implants 24-48 hrs after it arrives in the uterine cavity at the peak of luteal progesterone secretion; the embryo invades the endometrium and establishes contact with the maternal blood supply; progesterone from the CL is critical for establishment of pregnancy |
|
|
E2 levels during pregnancy |
they are nearly 100 fold higher during pregnancy than during the menstrual cycle |
|
|
estriol (E3) levels |
are an index of fetal well being (function of fetoplacental unit); need this to make DHEA from pregnenolone (occurs in the fetal adrenal) (DHEA is needed to make estradiol in the placenta) |
|
|
parturition definition, cause |
it is when the culmination of pregnancy is expulsion of the fetus from the uterus; the signal for parturition in humans is not yet known but many investigators favor the fetus as the source of the signal; changes in cortisol, progesterone, estrogen, prostaglandins, oxytocin, and cytokines are all candidates for this signal; oxytocin produces synchronized contractions of the uterus and is released in reponse to stretching of the cervix; the uterus will only respond to oxytocin during parturition when receptors for this peptide increase; oxytocin is released after labor has been initiated |
|
|
lactation definition, how does it happen |
milk produced by mammary glands in mammals after parturition; mammary glands are specialized sweat glands that secrete milk (fat, proteins including antibodies, electrolytes, and lactose); PROTEIN EXOCYTOSIS (MEROCRINE) AND LIPID DROPLETS ARE PINCHED OFF (APOCRINE) |
|
|
control of prolactin secretion |
sucking stimulus to spinal cord (T4) to hypothalamus --> dopamine (-) --> pit --> prolactin --> mammary gland; also secretes oxytocin from the post pit form the same stimulus |
|
|
oxytocin secretion- does what, produced where, stimulus |
responsible for milk let down, contraction of the utuerus after birth; produced in the hypo (SON, PVN), and stored in the post pit; can be released by suckling or by stretching of the cervix (as during parturition); release is affected by emotional stimuli (conditioned response (hear or see the baby), can be inhibited by stressful situations); involved in pair bonding between mother and child? |
|
|
physiological changes at menopause |
ovary becomes exhausted of primordial follicles - this results in decreased estrogen secretion; age related changes in hypothalamic-pit function as well; gonadotropin levels go up due to loss of negative feedback of ovarian steroids; physical, emotional, cognitive, and phenotypic changes occur due to loss of ovarian steroids |
|
|
symptoms of menopause |
vasomotor instability- hot flashes, hight sweats; real increase in core body temp; depressed mood; urogenital problems; decline in cognitive function; osteoporosis |
|
|
osteoporosis |
peak bone mass reached in 3rd decade; 95% of max bone density by age 18; during the 2-3 yrs that constitute the pubertal spurt- 60% of the final bone mass is deposited; normal bone density cannot be achieved if calcium is not deposited during this time |
