Female reproduction Flashcards
• Female puberty: signs in order of appearance
o First sign is breast bud
o Second is onset of pubic hair (due to adrenal androgens)
o Third is maximal growth
o Fourth is menarche
o Last you reach adult breast size and adult pubic hair levels
• Menstrual cycle
starts on first day of menstrual period & goes to first day of the next
o During menstruation: sex steroid levels are low
o Follicular phase: before LH surge
• At the beginning, estrogen starts to rise → follicular growth
• Estrogen has a sharp increase at the end of this phase → positive feedback in hypothalamus + LH surge
o Luteal Phase: after LH surge
• After the LH surge, estrogen levels stay up a little but not as high
• LH surge stimulates the corpus luteum to make progesterone
• Luteal phase is characterized by high levels of progesterone
• This is how you can tell whether someone has ovulated
• Progesterone and estrogen secretion by LH
• After 14 days if no pregnancy, LH, estrogen & progesterone levels fall → menstruation
o In the setting of low sex steroid levels, you begin the cycle again
• How can you monitor the menstrual cycle in an easy noninvasive way?
o Basal body temperature in the morning
o Levels are lower in follicular phase
o Higher in luteal phase due to progesterone
• What happens in pregnancy?
o HCG from placenta will take over for LH & stimulate estrogen/progesterone so they won’t fall
• Changes in the endometrium during the cycle:
o Follicular phase = ovary; Proliferative = uterus; high estrogen
o Luteal = ovary; Secretory = uterus; high progesterone + estrogen
• Follicular development:
o Early stages: hormone independent
• Primordial follicle, primary follicle
o Later stages: hormone-dependent
• Secondary follicle: LH → androgens
• Tertiary follicle
• Corpus luteum: LH stimulations makes you leutenized & make estrogen
• Ovarian steroid biosynthesis
o Pregnelone can go to progesterone, testosterone, and estradiol
o Note that it can go to testosterone/estraidal via 2 pathways:
• Adrenal androgen pathway: occurs in both ovaries and adrenal gland (more so in adrenal gland!)
• Or via progesterone pathway: dominates in ovaries
• Amenorrhea: causes
o Pregnant
o Low estrogen
o High estrogen
• Indices of estrogen secretion
o Breast development
o Body fat distribution
o Bone maturation
o Vaginal cell cornification
o Cervical mucus
o Proliferative endometrium
o Withdrawal bleeding after progesterone
• Indices of progesterone secretion
o Increase in basal body temperature
o Cervical mucus becomes more viscous
o Secretory endometrium
• Indices of androgen secretion
o Hirsutism
o Acne
o Temporal balding
o Voice deepening
o Changes in body habitus
o Clitoromegaly
o Menstrual dysfunction
• Causes of increased androgen secretion
o Polycystic ovary dz
o Androgen producing tumors of the ovary
o Cushing’s syndrome
o Adrenal hyperplasia
• PCOS: clinical and biochemical features
o Clinical sx: ameorrhea, dysfunctional bleeding, hirsutism, infertility, obesity
o Biochemical features:
• High LH:FSH ratio (due to increased GNRH pulse frequency) → stimulates cells to make more androgens
• High estrogen
• High androgens from ovary
• Decrease in sex hormone binding globulin
• Insulin resistance
o You get less stimulation of the follicle so you’re stuck in the early phase recruiting lots of follicles, making lots of androgens that cause follicle atresia → high estrogen puts you into positive feedback loop → system keeps going
o Adrenal also makes androgens but this is not the major contributor to the syndrome
o You get insulin production which can stimulate androgen secretion from the ovary- that’s why they also get diabetes like sx – insulin resistance, but they are still sensitive to high circulating insulin levels at the ovary → increased androgen levels from ovary
• Insulin directly stimulates androgen secretion in the ovary but the changes in LH to FSH ratio are very important in the pathophysiology
• Treatment for PCOS: options and goals
o Metformin: lower insulin level, so then they can ovulate
• Similarly have them lose weight
o You can also give them anti-estrogen: clomifine
o Goals of tx:
• Restoration of fertility,
• Tx of Hirsutism: oral contraceptions turn off pulse generator & turn off all production from the ovaries → androgen levels fall; also reduces free androgen levels
• Treatment of endometrial hyperplasia: give progesterone, bc cancer is a concern
• Treatment of metabolic syndrome: higher risk
• Causes of hypothalamic amenorrhea
o Diet/weight loss
o Exercise
o Stress: drops LH secretion
o Hyperprolactinemia: i.e. nursing, small prolactin secreting tumor
