Ch 26 Flashcards
What are the two ducts present in bipotential gonadal tissue? Which develops for each sex?
The müllerian duct develops for females
The wolffian duct develops for males
How does male sexual differentiation occur?
Y chromosomal genes secrete testis-determining factor -> sertoli cells -> mullerian inhibiting substance -> müllerian duct regression
Why does the wolffian duct regress in females?
In males leydig cells convert testosterone which get converted to dihydrotestosterone which encourages wolffian duct development. Without DHT the wolffian duct degenerates
How long is the corpus leteum active before becoming the corpus albicans?
12 days
What is the negative feedback effect of estrogen?
Negative feedback on FSH, LH, and GnRH
What is the positive feedback effect of estrogen?
The androgens secreted from the thecal cells are converted into estrogen (via aromatase) by the granulosa cells. That estrogen stimulates the granulosa cells to produce more estrogen.
What is the result of estrogen release from the ovary?
Endometrial proliferation
Secretion of cervical mucus to aid sperm entry
What causes the breakdown of structures holding the oocyte and mature follicle together?
Collagenase secreted by the follicle
What causes the egg to be released from the follicle with force?
Prostaglandins are released to cause thecal smooth muscle contraction
The corpus luteum is formed from _______
Combination of thecal and granulosa cells to form luteal cells
What are the 4 effects of progesterone?
Endometrium matures and becomes secretory
Endometrial cells deposit lipids and glycogen into cytoplasm
Thickening of cervical mucus prevents bacteria, sperm, and other particulates from entering the uterus
Higher basal body temperature
At the end of the luteal phase, progesterone and estrogen levels drop while _____ levels rise
FSH and LH
Why does menstruation excretion not clot?
Presence of plasmin
What hormones are secreted by the placenta?
Chorionic gonadotropin
Chorionic somatomammotropin
Progesterone
What property of hCG allows it to accomplish its role? What effects does it have?
It is structurally related to LH. This allows it to
1. Keep the corpus luteum from degenerating
2. Stimulate testosterone secretion in developing male testes
What hormone is structurally related to hCS? What does hCS do?
Related to growth hormone and prolactin
Contributes to lactation and regulation of mother’s metabolism
What are the effects of estrogen during pregnancy?
Inhibit FSH and LH (inhibiting ovulation)
Development of milk-secreting ducts in breasts
What are the effects of progesterone during pregnancy?
Inhibit FSH and LH (inhibiting ovulation)
Maintains endometrium
Suppress uterine contractions
Development of breast duct epithelium into secretory epithelium
Apart from oxytocin, what causes and reinforces contraction in the uterus and can even be used for an abortion?
Prostaglandins
What hormones stimulate and inhibit milk production?
Stimulated by prolactin
Inhibited by estrogen, progesterone, and prolactin-inhibiting hormone (PIH/dopamine)
Why would a mammary gland produce colostrum instead of breast milk?
Estrogen and progesterone are still high. High prolactin is still ineffective. Estrogen and progesterone must subside after delivery
