7.8 Flashcards
How do female sex hormones found in blood
Mainly bound to SHBG
Sex Hormones Binding Globulin
What does the synthesis of female sex hormones requires
Aromatase
What stage are oocyte before ovulation
Prophase of meiosis
They are called primary oocytes
How many primordial follicles are left by the time of puberty?
300,000
Whay happens to the oocyte when there is ovulation
Completion of meiosis 1 and the formation of secondary oocyte
Primary oocyte structure
Surrounded by granulosa cells
They secrete fluid
2nd stage of follicular development
70-80 days
15-20 follicles have accumulated fluids (hormones, FSH, proteins) in Antrum
Theca cells and granulosa cells continue to grow
Become Graafian follicles
What does the corpus luteum contians
Theca lutein cells
Granulosa lutein cells
They secrete mostly Progesterone and some Estrogen
GnRH secretion in females happens every
Follicular phase= 1-2 hours
Luteal phase= 5-6 hours
Ovarian cycle begins at
First day of menstruation
Follicular phase can be divided into
Menstrual flow
Proliferative phase
Other name for luteal phase
Secretory phase
Which pituitary hormone is usually higher?
LH
When FSH>LH
1st day of the cycle
Day of ovulation
14
Follicular phase is mainly under control of
Estrogen (E2=Estradiol)
After the release of secondary oocyte, what is left behind?
Hemorrhagic body
Which will become the corpus luteum
What happens to E2/P4 ratio after ovulation?
Decreases bcs the corpus luteum releases mainly P4
What happens if fertilization doesn’t occur
Corpus luteum will undergo apoptosis -> decreased P4 secretion
What will the decrease in P4 causes in the endometrium
Induces increase in PGF2a -> vasoconstriction -> necrosis of stratum functionale of the endometrium
Increased myometrial contractiliy
What happens if fertilization occurs
Syncyotrophoblasts induces secretion of hCG ->maintenance of P4 levels
Body temperature in the cycle
Follicular phase- lower
Luteal phase- higher
Job of theca interna cells
Secrete progesterone and androgens
Receptor on theca interna cells
LH R
Granulosa cells job
Produce Estrogens from androgens of the theca interna
Express FSH R
**in the follicular phase, FSH induces LH R on granulosa cells
Regulation of hormonal output in follicular phase?
Estradiol causes negative FB on ant pituitary and on hypothalamus
Regulation of hormonal output in around ovulation?
Estradiol causes Positive FB on ant pituitary and on hypothalamus
Regulation of hormonal output in luteal phase?
P4 causes Negative FB
