Menstrual Cycle and Ovulation Flashcards
What cycles make up the menstrual cycle?
Ovarian cycle + Uterine/endometrial cycle
What are the phases of the ovarian follicle cycle?
- Follicular phase
- Ovulatory phase
- Luteal phase
A primordial follicle contains what type of oocyte and what structure of granulosa cells surrounding it?
Primary oocyte
Surrounded by a single layer of pregranulosa cells
What does the primordial follicle release?
Paracrine factors
What type of follicle represents most of the ovarian reserve?
Primordial follicles
What happens to a majority of the primordial follicles?
Follicular atresia
A primary follicle contains what type of oocyte and what structure of granulosa cells surrounding it?
Primary oocyte
Surrounded by a single layer of granulosa cells - simple cuboidal
At what follicle stage are the glycoproteins for the zona pellucida beginning to be produced? - (ZP1,2,3,4)
Primary follicle
A secondary follicle contains what type of oocyte and what structure of granulosa cells surrounding it?
Primary oocyte
Surrounded by layers of granulosa cells - stratified cuboidal
What do secondary follicles release to stromal cells and what does that do?
Release paracrine factors to stromal cells so they differentiate into thecal cells (interna and externa)
As the follicle matures towards the secondary follicle, what is increased?
Vascularization
The follicle can release ______ to promote the development of 1-2 arterioles for vascularization on its way to the secondary follicle
Angiogenic factors
The zona pellucida has binding sites for?
Sperm
Preantral follicles have _____ endocrine function
Minimal
Are granulosa cells or thecal cells producing hormones during the preantral phase?
NO
Even during the preantral phase, granulosa cells do have a ____ receptor
FSH
Even during the preantral phase, thecal cells do have a ____ receptor
LH
As the antrum develops and fills with follicular fluid, the antral phase begins. What cell types increase during the antral phase?
Granulosa cells with subpopulations
As the follicle continues to grow and so does the antrum, growth at this stage becomes responsive to what?
Gonadotropins! - LH and FSH
LH will stimulate the theca interna cells to release?
Androstenedione
FSH will stimulate the granulosa cells to do what?
Convert the theca interna produced androstenedione into estrogen and progesterone
At the antral stage, the follicle is competent to eventually complete meiosis 1 at ovulation. When will the oocyte come out of cell arrest and continue the cell cycle?
With the LH surge at mid-cycle
How is cell cycle arrest achieved in the oocyte at the antral stage?
Elevated cAMP levels in the oocyte