Fertilization And Implantation Flashcards
During ovarian cycle, ___ releases GnRH which goes to the ___ and releases ___ which act on ___
Hypothalmus releases GnRH which goes to the pituitary gland which stimulates release for LH and FSH which act on the ovaries
- Function of FSH?
2. Function of LH?
- Stimulates the development of ovarian follicles and production of estrogen by follicular cells
- Triggers ovulation; stimulates follicular cells and corpus luteum to produce progesterone
When the corpus luteum is degenerated, it is called?
Corpus albicans
Beginning of ovarian cycle:
- What stimulates primary stage follicles to grow?
- What else does this hormone do that significant at this stage
- What does GDF-9 do?
- What two cells produce estrogen?
- FSH - and only one fully matures and only one oocyte is discharged
- Stimulates maturation of follicular (granulosa) cells
- Growth differentiation factor mediates proliferation of follicular cells
- Granulosa and thecal cells
Name 3 things estrogen does to the body
Thins cervical mucus, uterine endometrium to enter follicular/proliferative phase, and stimulate pituitary gland to secrete LH
During mid cycle, there is an LH surge. What does this cause?
Causes oocyte to complete meiosis I and initiate meiosis II, stimulates production of progesterone by follicular cells, and causes follicular rupture and ovulation
During ovulation, FSH and LH stimulate follicle to do what?
Release the egg
- What are the 4 phases of a follicle growth?
- What is FSH role in these phases?
- What happens in order to get from phase 3 to phase 4?
- Primodial, growing, vesicular (antral) and vesicular (graafian)
- Primordial develop into growing independent of FSH. As cycle proceeds, FSH secretion recruits growing follicles to develop into antral.
- Estrogen stimulates increased production of LH, causing the the follicle to enter graafian phase to complete meiosis I
Where is meiosis II arrested?
In metaphase ~3 hours before ovulation
- Corpus luteum will form after ovulation under the influence of?
- What does corpus luteum do?
- What do progesterone and estrogen cause?
- LH
- Secretes progesterone
- They cause endometrial layer to enter secretory phase (preparation for implantation)
- After how many days of no fertilization will the corpus luteum start to shrink?
- If fertilization does occur, what happens?
- When pregnant, when does corpus luteum disappear?
- On day 9 of ovulation (decrease progesterone= menstrual bleed)
- HCG will prevent degeneration of corpus luteum
- Around month 4 of pregnancy (also when it stop secreting progesterone)
How is oocyte transported?
When ovary releases the egg, fimbriae catches it and moves it towards uterine cavity via contraction of fallopian tubes/propulsion from cilia.
- Where does fertilization occur?
2. How long does sperm remain viable? Secondary oocyte?
- Ampullary region of uterine tube
2. Sperm= 48 hours; secondary oocyte= 24 hours
What two things must sperm go through in order to fertilize oocyte?
Capacitation and acrosome reaction
What happens in capacitation?
Functional changes cause the tails of sperm to beat vigorously; removal of glycoprotein from acrosomal head causes receptors to be made available