W8L2-3 Female Reproductive System 1&2 Flashcards
The female gonads are the ____, which, together with the _____ and _____ constitute the female reproductive tract
Ovaries; uterus; fallopian tubes
Two functions of ovary:
- oogenesis, 2. secretion of female sex steroid hormones (progesterone and estrogen)
What is the normal range of days of the ovarian cycle?
When is the “start” of the cycle?
25-30 days (28 days by convention)
Starts at menstruation
What is the first half of the ovarian cycle called?
What is the midpoint?
What is the second half of the ovarian cycle?
1st 14 days = Follicular Phase
@14 days = Ovulation
2nd 14 days = Luteal Phase
Do females keep producing new oogonia after fetal development?
No, they start with around 2 million oocytes at birth, and by puberty 400,000 remain. By menopause, only a few are left.
What is the dominant hormone of the follicular phase?
What undergoes development during this period?
Estradiol, which is the most important estrogen in non-pregnant women.
The dominant follicle develops.
What is the dominant hormone of the luteal phase?
What undergoes development during this period?
Progesterone (P4) {also E2 but P4 is dominant}
Corpus luteum develops
What are the two phases of the endometrial and myometrial cycles?
- Proliferative phase: endometrium regenerates, myometrium is excitable during sex
- Secretory Phase: endometrium proliferates secretory glands and fills with fluid, myometrium excitability decreased
At the end of the ovarian cycle, [progesterone] decrease causes what two things to occur that ultimately lead to menstruation?
- Uterus secretes Prostaglandin F2α (PF2α) which causes vasoconstriction, leading to necrosis of outermost uterine layer, erosion of walls
- Progersterone decline induces apoptosis, causing matrix metalloprotease activity to increase, also causing erosion of vessel walls, causing bleeding
What are the effects of estrogens during puberty?
Development of external genitalia, myometrium, breasts, other secondary sex characteristics
What are the effects of estrogens on myometrium in adults?
Oxytocin receptors increase, making the myometrium more excitable
What is the name for E1, E2, E3?
E1: estrone
E2: estradiol
E3: estriol
How many carbons are in androgens vs estrogens?
Androgens are 19C, Estrogens are 18C
What are the effects of estrogens on cervical secretions?
More fluid, less viscous secretions, lubricating the vagina and having short carbon-chain fatty acids introduced to give scent
What is the difference between the effects of Progesterone vs Estrogens on the motility of fallopian tube and cilia?
Estrogens increase motility, Progesterone decreases it
What hormonal changes cause the “LH surge” to occur?
Normally E2 is at lower concentrations and inhibits LH/FSH secretion via negative feedback
LH surge occurs with high concentrations of E2, when different receptors are activated and cause increased LH/FSH secretion via positive feedback (only in females)
What is the effect of the LH surge?
Ovulation occurs at the appropriate time, and only the biggest follicle is able to mature while the others degenerate
During pregnancy, prolactin secretion increases but lactation does not occur. Why?
Prolactin stimulates breast alveoli development but lactation does not occur bc estrogen concentration is high
What are the effects of estrogens on bone?
Induces closure of epiphyseal cartilage
OPG increases, causing decreased osteoclast activity and mineral content to increase
Deficiency of estrogen (as in menopause) leads to osteoporosis
What is the effect of estrogens on blood pressure?
Estrogens induce activity of eNOS, causing NO to be produced and vasodilation occurs, lowering BP