9. Ovarian Function Flashcards
How long does sperm live?
48 hours
How long does secondary oocyte live?
24 hours
What happens in the proliferative phase of menstrual cycle?
A new uterine lining forms
What are the phases of menstruation and what hormones are involved?
Two Phases -Follicular/Proliferative (Estrogen) - Luteal/Secretory (Progesterone and Estrogen)
What female secondary sex characteristics are controlled by Estrogen?
- Breast development - Distribution of bodyfat
What adrenal androgens control some female traits?
- Growth of pubic and axillary hair - Sex drive
Describe the female reprodictive system anatomy
Describe the structure of the ovary
Describe the structure of the Uterus
What is the structure of the Endometrium?
coiled with blood vessels and secretory structure
What is the structure of the Myometrium?
Muscle layer that must contract to deliver the baby, a muscular wall. Very vascularised
What is the function of the fimbriae?
The ovary is sitting around the finger like structure, not physically connected.
On ovulation the oocyte must be picked up the fimbriae into the fallopian tube.
What is are the layers of the mature follicle?
The theca interna is responsible for the production of androstenedione, and indirectly the production of 17β estradiol respond to LH
A granulosa cell produce Estrogen from Androgens produced by theca cells and produces inhibin to inhibit FSH in late follicular phase
At what stage of the cell cycle are secondary oocytes arrested in?
Metaphase II, when fertilized metaphase II continues and polar bodies are released
Describe the process of oogenesis
What are the phases of the menstrual cycle?
- Follicular/Proliferative phase
- Follicle growth in ovary (egg matures)
- Endometrium starts to build up
- Days 0-13
- Ovulation
- Ripened follicles and release of oocytes (s)
- Day 14
- Luteal/Secretory phase
- Ruptured follicle transforms into corpus luteum in preparation for pregnancy
- Day 15-28
Describe the endometrial lining throughout Uterine cycle
- Menses
- No pregnancy
- Bleeding from uterus as endometrium is shed
- Proliferative phase
- New layer of endometrium in preparation of pregnancy
- Secretory phase
- Conversion of endometrium to secretory structure to promote implantation
Describe the menstrual and uterine cycles
What is the hormonal control of the Follicular phase?
- FSH stimulates follicualr development
- Maturation to secondary and tertiary follicle
- Granulose cells produce Estrogen
- Positive feedback develops follicles & increse estrogen
- Negative feedback decreases FSH and LH secretion
- LH stimulates thecal cells to produce androgens converted to estrogen by armoatase in granulosa cells
What are the hormonal regulator of Ovulation?
- High estrogen
- LH & FSH surge
- Primary oocyte - first meiotic division to form secondary oocyte
- Lutenisation
- High inhibin
- INhibits FSH and stops new follicle from forming
- Low-level progesterone
- Positive feedback on GnRH and LH
What happens to the follice and uterus during the Follicular phase?
- Follicle
- Enlarges, antrum forms
- One dominant follicle develops
- Uterus
- Menstruation
What happens to the follicle, uterus and cervics during ovulation?
- Follicle
- Primary oocyte completes first meiotic division to form secondary oocyte
- Ovulation
- Differentiation of follicular cells into luteal cells
- Decreased estrogen
- Uterus
- Estrogen
- Proliferates
- Progesterone receptors
- Estrogen
- Cervics
- Abundant, clear non viscous
What are the hormonal control of menstrual cycle during the luteal phase and late luteal phase
- Granulosa cells
- Form corpus luteum
- Progesterone
- Form corpus luteum
- High progesterone & estrogen
- maintain endometrium
- Reduce GnRH, LH, FSH
- Inhibin inhibits follicle
In the early - mid luteal phase we don’t follicle anymore but we have luteum. No more estrogen, so no more LH and FSH.
Corpus luteum produces progesterone and a BIT of estrogen. The high estrogen and progesterone maintain endometrium and revert back to our negative feedback. Reduce LH and FSH.
The inhibin also inhibit follicular development because we assume conception has happened.
After fertilization Estrogen and Progesterone prepares for pregnancy and Uterus becomes Secretory and vascular.
Progesterone cause the cervical mucus becoming thick, sticky viscous. WE don’t want another fertilization.
Progesterone increaases Basal Body temperature. AFTER ovulation.
What happens to CL, Uterus and Cervics during luteal phase
- Corpus luteum
- Increasex2 Progesterone
- Increase Estrogen
- Uterus
- Prepare for pregnancy
- Vascular
- Secretory
- Cervics
- Thick sticky viscous mucus
- Increase basal body temperature
