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42 Cards in this Set
- Front
- Back
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Name 3 changes that occur when female child matures to adult
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1. development of secondary sex characteristics
2. growth spurt 3. achievement of fertility |
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what is adrenarche and when does it occur?
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regeneration of zona reticularis in adrenal cortex and production of androgens.
between ages of 6 and 8 yrs |
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what is gonadarche and when does it occur?
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pulsatile GnRH secretion from hypothalamus is increased -> pulsatile secretion of LH and FSH from anterior pituitary -> ovary stimulation and estrogen release
around age 8 |
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does gonadarche lead to any phenotypic changes?
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not at first. initially, hormonal changes occur during sleep. eventually, LH and FSH pulsatility lasts throughout the day, leading to ovary stimulation and estrogen releases
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what is thelarche and when does it happen?
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breast development
begins at 10 yrs |
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what is pubarche and when does it happen?
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pubic and axillary hair growth
11.2 yrs |
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when does peak height velocity or maximal growth occur?
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12 yrs
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when does menarche occur?
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13 yrs
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on average how much time elapses from breast bud development to menarche?
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2.5 yrs
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what are the 3 hormones produced as a result of adrenarche?
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1. dehydroepiandrosterone sulfate (DHEAS)
2. dehydroepiandosterone (DHEA) 3. androstenedione |
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what is the first phenotypic sign of puberty and when does it occur?
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breast bud development, or thelarche, at around 10yrs
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what causes thelarche?
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increased estrogen circulation
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usually, what comes first, thelarche or pubarche?
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usually thelarche, but the reverse order is a normal variant
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what is a likely cause of peak height velocity?
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estrogen, leading to increased levels of growth hormone and somatomedin-C
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how long after menarche does the menstrual cycle become regular?
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about 2 years later
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what 4endocrine structures are involved in maintaining the menstrual cycle?
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1. hypothalamus
2. pituitary 3. ovaries 4. uterus |
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what are the 2 phases of the menstrual cycle that describe changes in the ovary?
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1. follicular phase
2. luteal phase |
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what are the 2 phases of the menstrual cycle that describe changes in the endometrium?
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1. proliferative phase
2. secretory phase |
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big picture: what happens during follicular phase?
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FSH from pituitary -> development of primary ovarian follicle -> follicle makes estrogen -> estrogen causes uterine lining to proliferate
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on day 14, LH spike leads to what?
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LH stimulates ovulation, the release of ovum from follicle
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when does luteal phase start?
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after ovulation
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remnants of follicle left behind in ovary is called what? what does it do?
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corpus luteum
secretes progesterone to maintain endometrial lining in preparation to receive ovum |
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what does progesterone do during the menstrual cycle?
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Progesterone Prepares
lining to receive ovum |
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what happens in absence of fertilization?
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corpus luteum degenerates and progesterone levels fall
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what is menstruation and what triggers it?
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endometrial lining is sloughed off in response to low progesterone
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FSH release from pituitary signals beginning of menstrual cycle. what causes FSH release?
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withdrawal of estrogen and progesterone during luteal phase of prior cycle
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what does FSH at beginning of cycle actually do?
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stimulates growth of 5-15 primordial follicles, initiating the follicular phase
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how is estrogen introduced into the cycle?
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one primordial follicle becomes dominant and starts maturing; the developing follicle produces estrogen
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what is the role of estrogen in the menstrual cycle?
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estrogen enhances follicular maturation and increases production of LH and FSH receptors in an autocrine fashion; LH also rises, stimulating the synthesis of androgens, which are converted back to estrogen
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rising estrogen provides negative feedback on FSH production by the pituitary. how is the dominant follicle protected from the FSH drop?
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increase number of FSH receptors
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what signals the end of the follicular phase and start of luteal phase?
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rise in estrogen to critical level -> LH spike from anterior pituitary -> LH spike leads to ovulation
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how much time is available for fertilization before ovum degenerates?
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fertilization must occur within 24 hrs of ovulation
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how long does it take released ovum to pass into fallopian tube and then into uterus?
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3 to 4 days
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what cells of the follicle become the corpus luteum?
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granulosa and theca interna cells
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what does the corpus luteum make?
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estrogen and lots of progesterone
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specifically, how does progesterone affect teh endometrium?
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becomes more glandular and secretory to prepare for implantation of fertilized ovum
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good way to remember roles of estrogen and progesterone?
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Estrogen Enlarges Endometrium
Progesterone Prepares it |
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if there is fertilization, how is the corpus luteum kept functional?
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upon fertilization, developing trophoblast makes human chorionic gonadotropin (HCG), a glycoprotein similar to LH, to maintain the corpus luteum
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when does the placenta start making its own estrogen and progesterone to maintain the endometrium?
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at 8 to 10 weeks gestation
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what hormone negatively feeds back on pituitary FSH production?
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estrogen
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how long does it take the corpus luteum to degenerate?
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about 14 days
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estrogen production by the corpus luteum is a two cell, two step process. explain.
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theca interna cells produce androstenedione in response to LH
granulosa cells convert androstenedione to estradiol in response to FSH |
