Female reproductive physiology Flashcards
Describe Oogenesis
1- Born with primary oocyte that is stopped at meiosis I.
2- Once a month secondary oocyte is formed and beings meiosis II ( haploid ) and 1st polar body is formed
3- Secondary oocyte is ovulated and then fertilized
4- after fertilization meiosis II is completed and oocyte splits into zygote ( diploid ) and second polar body
What’s the difference between oogenesis and spermatogenesis
Female gametes were formed before birth just not matures. Sperm is produced daily
What’s the difference between the oogonium and the primary oocyte
Primary oocyte has twice the amount of chromosomes but both are still considered diploid
Explain the Follicular phase
The development of the Follicle ( Day 1 - 14 ). Might take just 7 days, it’s variable.
Explain the steps of the follicular phase
1- Primordial follicle becomes primary oocyte: granulosa develops and ZP is formed
2- Antrum is developed in the cell and theca cells develop = Graafian follicle
3- Granulosa and theca cells continue to divide until day 14
4- follicle is now so large that it is pocking at the ovarian surface , building up the pressure in the antrum
5- Results in ovulation , where secondary oocyte is released from ovary ( usually day 14 )
6- rest of the follicle left fills up with blood and becomes the corpus luteum
What are the theca cells
Cells at the Graafian follicle stage that can differentiate into theca internal and theca externa cells.
What is Mittelschmerz
irritation in the middle of menstrual cycle that is due to blood filing into the peritoneum after the follicle ruptures
Why is corpus luteum important
Produces progesterone needed in second half of ovarian cycle
What hormones are released during the follicular phase
FSH ( mainly ) & LH
What hormones are released in ovulation
LH surge
What hormones are released in luteal phase
LH ( mainly ) & FSH
What are the two phases in the ovarian cycle
The follicular phase and the Luteal phase
Explain the hormonal control during the ovarian cycle ( in terms of follicular phase, ovulation and luteal phase)
1- Gonadotrophin releasing hormone is released at start of month stimulating release of follicle stimulating hormone and Luteinizing hormone in anterior pituitary
2- FSH results in forming of granulosa cells which release estrogen
3- estrogen has negative feedback on FSH and GNRH and a bit on Leuteinizing hormone
4- LH released at the beginning in small amounts stimulates theca cells to produce androgens until it’s inhibited by estrogen
5- After day 10 estrogen starts to positively feedback on LH production = LH surge that causes ovulation
6- corpus luteum formed after ovulation produces progesterone and estrogen that negatively feedbacks on LH and GNRH
7- after 10 days when corpus luteum breaks down, GNRH rises again and cycle is repeated
What is day 0-4 in uterine cycle and explain
Menstruation: stratum functional decays as there are no hormones
What is day 4-14 in uterine cycle and explain
Proliferative phase : estrogen levels rise in follicular phase = cell proliferation and glandular development will happen in endometrium ( cell wall thickens )
