11 menstrual cycle, ovary and follicle Flashcards
blood supply in the ovaries
Ovarian arteries
arise level of renal arteries
right ovarian veins-> IVC
left ovarian veins -> left renal vein
anastomosis of vascular elements in uterus
- ovarian arteries gives branches to fallopian tube
- ovarian arteries anastomoses with uterine artery (branch internal iliac)
- uterine arteries anastomose with vaginal artery (branch of internal iliac)
where does gamete formation and follicle maturation take place in the ovary?
cortex
what is in the cortex of the ovary?
- epithelial lining
- stromal cells
- gametes (oogonia, follicles)
what is in the medulla of the ovary?
- stromal cells
- mesenchymal cells (mulitpotent stem cells)
- remnants of embyronic wolffian duct
what is in the hilum of ovary?
- blood vessels
- lymphatics
- hilus cells (ovarian Leydig cells produce testosterone)
consequence of pregnancy on menstrual cycle
- human chorionic gonadatrophin from placenta prevents degeneration of corpus luteum
- hCG signal pituitary to secrete LH
- CL continues to secrete progesterone until end of 4 months of pregnancy
- then placental progesterone levels high enough to take over
the role of oestrogen on stratum functionale during proliferative phase
- mitotic activity in glands
- proliferation of stromal cells
- increase thickness of endometrium
- increased length spiral arteries
what happens to stratum functionale during secretory phase
- glands become saw toothed and secretory- under progesterone control
- spiral arteries coil
what happens to the endometrium during secretory phase
- Surface epithelial cells have short microvilli and loses surface negative charge
- Endometrial gland full of secreted material- used as nutrients by conceptus
- Optimal vascular supply
Endometrium is in a receptive phase now: allows implantation.
The Implantation window is short (5-7 days after ovulation)
type of epithelium in endometrium
simple columnar epithelium
what happens in the menstrual phase to the endometrium
- cessation of progesterone and oestrogen
- involution of functional layer of endometrium
- rise in endothelin and thromboxane
- vasoconstriction of spiral arteries, cessation of blood flow and ischaemia of functional layer
- rupture of arteries and shedding of blood into uterus
- basal layer of endometrium remains
other changes in menstrual cycle:
Proliferative phase of endometrium
ovulation
post ovulation
prior to and during menstruation
proliferative phase: thinning of cervical mucus to allow passage of sperm
Increase in fat deposition in mammary glands
ovulation: Mid cycle pain, rise in basal temperature
post ovulation: Plugging of cervix by thickening of mucus
menstruation: prostaglandins- cramps
