uterine cycle.pptx

Uterine cycle

1. UTERINE CYCLE

2. The uterine wall Endometrium Myometrium Perimetrium

3. Endometrium Undergoes hormone modulated cyclic changes during different phases of the menstrual cycle

4. Layers of the endometrium Functional layer Basal layer

5. The menstrual cycle is the period during which -- the oocyte matures --the oocyte is ovulated --the oocyte enters the uterine tube

6. The hormones produced by the ovarian follicles and corpus luteum (estrogen and progesterone) produce cyclic changes in the endometrium

7. The endometrium is a “mirror” of the ovarian cycle

8. The average menstrual cycle is 28 days (23-35 days) with day 1 of the cycle designated as the day on which menstrual flow begins

9. Phases of menstrual cycle Menstrual phase Proliferative phase Luteal phase Ischemic phase Pregnancy phase

10. Menstrual phase The functional layer of the uterine wall is sloughed off and discarded with the menstrual flow which lasts 4-5 days Blood + endometrial tissue Eroded endometrium is thin

11. Proliferative phase Follicular phase, estrogenic: lasts about 9 days Coincides with the growth of ovarian follicles and is controlled by estrogen secreted by these follicles 2 to 3 fold increase in the thickness of the endometrium

12. Cont: Phases of repair and proliferation Surface epithelium reforms and covers the endometrium The gland increase in number and length The spiral arteries elongate

13. Luteal phase Secretory : lasts 13 days Coincides with the formation, functioning and growth of corpus luteum Glands become wide, tortuous and saccular Endometrium thickens because of the influence of progesterone and estrogen

14. If fertilization does not occur Corpus luteum degenerates Decreased estrogen and progesterone Secretory endometrium enters an ischemic phase Menstruation occurs

15. Ischemic phase Occurs when oocyte is not fertilized Spiral arteries constrict, giving the endometrium a pale appearance Loss of 20-80 ml of blood Menstruation lasts 3-5 days

16. Thank you