Reproductive Hormones and Menopause Flashcards
What axis regulates sex hormones?
the hypothalamic pituitary gonadal axis (HPG)
Describe the hormones released throughout the HPG in Males
hypothalamus releases GnRh, ant pit releases FSH and LH
What effects does FSH have on males
FSH indirectly stimulates spermatogenesis, stops sperm dying, stimulates mitotic activity in sertoli cells at puberty
describe the effects of the negative feedback from testosterone on FSH, LH and GnRH
negative feedback by testosterone inhibits FSH and LH release from ant pit and GnRH from hypothalamus
What effects does LH have on males
stimulates leydig cells to make testosterone
describe the role of testosterone in males
increases muscle mass, reduces fat mass, increases bone density, causes hair growth and a deep voice
discuss age related reproductive decline in men and its effect on testosterone, LH, FSH
testosterone decreases with age, LH and FSH increase but become less effective
Describe the role of FSH in females.
FSH binds to receptors on granulosa cells in ovary to stimulate follicle growth, stimulates estrogen secretion from growing follicle, increases LH receptors in follicle, once estrogen levels high enough it induces +ve feedback for LH
Describe role of LH in females
binds to LH/HCG receptors on theca cells to stimulate androgen production (progesterone -> androgens -> estrogen), stimulates ovulation and converts primary oocyte into fertilisable egg, maintenance of corpus luteum and progesterone production
What cell is the primary producer or progesterone and estrogen?
granulosa cell
describe the intertwining relationship between granulosa and theca cells and female hormones
theca cells use progesterone from granulosa cells to produce androgen, granulosa cells require androgens to make estrogen
describe the relationship between granulosa cells and follicle growth
the number of layers of granulosa cells increases as the follicle growth, increasing estrogen
High levels of ______ mid cycle cause ____ feedback to prompt surge in ____ causing ovulation
estrogen, positive, LH
corpus luteum regresses to corpus albicans and estrogen and progesterone secretion decreases causing _______
menstruation
compare mucous stimulated by estrogen to that stimulated by progesterone
estrogen stimulates watery cervical mucous allowing sperm through cervix
progesterone stimulates viscous mucous of cervix if implantation occurs where sperm can’t pass and neither can baby
describe the main functions of oral contraceptives
stop ovulation by preventing surge of LH, thickens cervical mucous to stop sperm penetration, stops endometrial thickening so fertilized embryo can’t implant
What other systems does estrogen impact?
libido, memory, mood, bone growth, cardio protection, bone physiology
What other systems does progesterone impact?
breast development, skin health, regulation of GH, TSH, melatonin, insulin
with age primordial follicles are _____ _______ to FSH
less sensitive
Describe some changes that occur in menstrual cycle as women age
anovulatory cycles become more common, number of cycles with >1 oocytes increases, menstruation becomes lighter
list some consequences of follicle depletion in women
less estrogen available as ovarian follicles produce 95% of all estrogen, reduced negative feedback which increases FSH and LH
What are most symptoms of menopausal transition caused by?
erratic hormones especially estrogen
What is early menopause characterised by?
persistent differences in cycle length by >/=7days
describe the difference in FSH and LH levels in reproductive and post menopause years
reproductive- FSH 10mlU/mL, LH 10mlU/mL
post menopausal- FSH >100mlU/mL, LH >100mlU/mL
What factors can cause early menopause
chemo, smoking, chronic malnutrition
describe how hormone replacement therapy can increase risk of cancer
HRT can cause breast development and endometrial proliferation where this unexpected development has higher risk of cancer cells
What is the term for gradual decline in testosterone in men as they age?
andropause
