Mod 3.2 Ovarian Structure/Function Flashcards
Where are the ovaries located?
On either side of the pelvic cavity
What are the two layers of the ovary?
- Outer cortex
- Thicker
- Presence of follicles
- Inner medulla
- contains the Stroma
- Neurovascular supply
- contains the Stroma
What is the hormonal control of ovarian function?
- GnRH - > anterior pituitary -> gonadotropins (FSH/LH) -> gonadal sex hormones (estrogen/progesterone)
- Hypothalamus secretes GnRH
- GnRH acts on ant pit to release gonadotropins (FSH/LH)
- FSH acts on Granulosa cells which influence oocytes and produce inhibin (Neg feedback to control FSH release from ant pit)
- LH acts on Theca cells to produce androgens which are converted to estrogen by the granulosa cells
- At low to moderate levels estrogen provides neg feedback at the ant pit and hypothalamous
What is a difference between the pulsatile release of GnRH from the hypothalamus in females vs males
In females, the frequency and amplitude of the pulsatile release of GnRH changes over the course of the menstrual cycle
What marks the tertiary follicle stage?
Production of antral fluid by granulosa cells
A mature follicle prepared for ovulation is called:
Graafian follicle
What sex hormone receptors are found on granulosa cells?
Granulosa cells feature FSH receptors (no LH receptors) (Therefore, fsh acts on granulosa cells)
- initially - mature follicle has LH receptors present
- Late expression of LH receptors on granulosa cells aids in final follicular maturation in preparation for ovulation
Which receptors are found on theca cells?
Theca cells have LH receptors (respond to LH production)
What is the effect of FSH on granulosa cells?
FSH stimulates granulosa cell multiplication and estrogen production; antrum enlargement (fluid establishment)
How are theca cells important for granulosa cell production of estrogen?
Theca cells aid granulosa cells to produce estrogen
- Theca cells have enzymes to produce androgen
- Granulosa cells then use aromatase to synthesize estrogen from androgens
Granulosa cells are similar to which cells in seminiferous tubules of the male reproductive tract
Granulosa cells similar to Sertoli cells
- Both modulates germ cell microenvironment
- Stimulated by FSH and gonadal sex hormone (estrogen/testosterone)
Theca cells are similar to which cells in the seminiferous tubules of the male reproductive tract?
Theca cells similar to leydig cell:
- produce androgens under stimulus by LH
Ovulation depends on a surge of which hormone?
LH
What is ovulation?
When the thin walls of the follicle and ovary rupture at their junction (enzymatic digestion)
- Secondary oocyte surrounded by zona pellucida and granulosa cells
- carried out of ovary and onto ovarian surface by antral fluid
Ovulation:
- When the thin walls of the _____ and _____ rupture at their junction (______ digestion)
- _______ surrounded by ______ and ________
- carried out of ovary and onto ovarian surface by ________
Ovulation:
- When the thin walls of the follicle and ovary rupture at their junction (enzymatic digestion)
- Secondary oocyte surrounded by zona pellucida and granulosa cells
- carried out of ovary and onto ovarian surface by antral fluid
