Reproductive Physiology Flashcards
role of hCS in pregnancy
human chorionic somatomammatropin
decreases maternal glucose utilisation
increased plasma fatty acids - increases glucose/FA availability for foetus
? role in lactation
role of PTH-rp in pregnancy
parathyroid hormone-related peptide
mobilises maternal Ca for calcification of foetal bones
(if mum doesn’t get enough Ca from diet)
role of relaxin in pregnancy
maybe softens cervix
loosens pelvic connections
VASODILATOR - increased blood flow, increased CO, increased venous return
role of CRH in pregnancy
placental corticotropin releasing hormone stimulates DHEA (dehydroepiandrosterone) production by the foetal adrenal cortex this is important in initiation of parturition
when does menstruation return if no breast feeding
4-6 weeks
role of hCG in the first trimester
produced by blastocyst/chorion
prolongs life of corpus luteum
CL grows and increases production of oestrogen and progesterone
maintains the uterine lining
AFTER 10 WEEKS the placenta produces these
3 uses/roles of hCG
pregnancy test
morning sickness - triggers vomiting centres
triggers male foetal gonads to produce androgens –> develop genitalia (end of first trimester)
2 roles of oestrogens during pregnancy (2/3rd)
stimulates growth of uterine myometrium muscle (for labour)
stimulates development of mammary milk glands
3 roles of progesterone during pregnancy (2/3rd)
- suppresses the myometrium contractions
- promotes mucus plug formation
- stimulates development of mammary milk glands
which hormone produces the environment for implantation
progesterone
spike in progesterone (in luteal phase) triggered by what
degeneration of the follicle
why do levels of FSH and LH rise during luteal phase
as the inhibition by oest and prog have been removed so they can stimulate follicle development again
what causes the slough of the uterine lining
the low levels of prog and oest (because of degeneration of CL)
what causes the low levels of oest and prog in later luteal phase
the degeneration of the CL
adrenarche
age
hormone
causes (x3)
6-8 years of age adrenal gland secretes androgens DHEA breast development starts pubic hair growth growth spurt
menarche age what does it mean what increases onset related to what
10-16 years
ability to produce mature ova and endometrium can support a zygote
increased FSH and LH from anterior pituitary
onset related to critical level of body fat
changes in secondary sexual characteristics female
pubic hair
growth/maturation of repro tract (including uterus)
fat deposition (breasts, bum, thighs)
closure of epiphyseal plates
somatic growth
when
induced by
begins 2 years earlier in girls
growth induced by gonadal sex steroids, GH and insulin-like growth factor (in both sexes)
changes in GnRH release in boys vs adults
frequency of bursts increases until GnRH, FSH, LH levels are same as adult
what causes secondary sexual features
rising levels of testosterone
what does Tanner stages describe
the development of secondary sexual characterisits
possible triggers of menopuase
- oocyte depletion?
- remaining follicles might not be as sensitive to LH and FSH?
- age related changes in CNS alter GnRH secretion?
progressive physiological changes in menopause
- ovaries atrophy
- decrease in oestrogen secretion with concomitant increase in LH/FSH
- increased LH stimulates ovaries to produce androstane-dioe
- androstene-dione is androgen precursor -> hirsuteness and precursor for estrone
overall decrease in oestrogen -> breast and repro tract atrophy, vaginal dryness - increase bone mineral loss -> decreased density
- increase CV risk due to lack of production of oestrogen (protective effect)
dominant oestrogen pre-menopause vs post menopause
beta-oestradiol
estrone
