FEMALE REPRODUCTIVE CYCLE /OVARIAN CYCLE/MENSTRUAL CYCLE

        1. The periodic changes occurring every month in ovary and uterine wall in human females from Menarche to menopause are collectively called as female Reproductive Cycle.

        2. Discharge of blood, unfertilized egg, destructed cells etc. through vagina in periodic manner is termed as menstruation.

        3. Cycle is completed in 28 days with an individual variation of 1 or 2 days.

        4. Different phases of menstrual cycle can be explained as follows:

      (A) Menstrual / Destructive Phase:

        1.  Bleeding through vagina indicates onset of menstrual cycle.

        2.  It lasts for 4-5 days and commonly termed as ‘Menses’ which occurs in absence of fertilization.

        3. During this phase there is sharp decline in level of progesterone.

      4. During this phase internal lining of vagina, fallopian tube. endometrium of uterus get destructed along with blood vessels which results in bleeding.

  5. Broken tissue, degraded cells, blood, unfertilized egg etc. collectively form menstrual flow.

      (B) Follicular Phase or Proliferative Phase:

        1. It occurs between 5th day to 14th day of menstrual cycle.

        2. During this phase, pituitary releases FSH and its level continuously increases.

        3. FSH stimulates growth of primary follicle into Graafian follicle.

        4. It stimulates follicular cells to secrete estrogen.

        5. It stimulates repairy of internal lining of vaginal mucosa, fallopian tube etc.

        6. In the end, the internal lining becomes thick and highly vascularized.

Thus it becomes ready to receive sperm and facilitates fertilization.

      (C)Ovulatory Phase:

     1. Release of ovum is called as ovulation which occurs in midway of menstrual cycle i.e. nearly on 14th or 15th day.

        2. Level of LH increases.

        3. Rupture of Graafian follicle and release of ovum in observed.­

        4. It stimulates development of corpus luteum.

     5. Blood vessels and secretory glands of endometrium become more prominent.

        6. It is shortest phase of menstrual cycle.

      (D) Luteal Phase / Secretory Phase:

        1. It is longest phase and extends from 15th day to 28th day of menstrual cycle.

        2. It shows following changes.

        i) Corpus luteum starts secreting progesterone and negligible amount of estrogen is also secreted.

        ii) Progesterone maintains thickening of endometrium, hence called as pregnancy hormone.

        iii) It stimulates uterine glands.

        iv) If fertilization takes place, level of progesterone is maintained to sustain development of embryo.

        v) If fertilization fails, corpus luteum degenerates producing corpus albicans and menstruation occurs.

 Hormonal control of menstrual cycle.

        1. Menstrual cycle is controlled by FSH & LH from anterior pituitary and estrogen as well as progesterone from ovary.

        2. First half of cycle is called as proliferative phase or follicular phase which is controlled by FSH and estrogen.

    3. In the beginning Hypothalamus produces GRF i.e. gonadotropin releasing factor which stimulates pituitary to secrete FSH. FSH is responsible for growth of follicle and secretion of estrogen from follicular cells.

        4. Estrogen brings about repairy and growth of internal linings of blood vessels.

        5. Second half of the cycle is luteal phase or secretory phase which is controlled by LH & progesterone.

    6. During first half, level of estrogen increases which stimulates secretion of progesterone in negligible amount.

        7. Release of LH brings about ovulation & development of corpus luteum.

        8. Corpus luteum starts secretion of progesterone & negligible amount of estrogen which make uterus more thick, vascular and glandular.

        9. If fertilization takes place corpus luteum is maintained along with level of progesterone.

      10. If fertilization fails corpus luteum degenerates producing corpus albicans  and level of progesterone falls down which results in menstruation.

 

1)       What is puberty?

2)      What does menarche indicate?

3)      What is the source of gonadotropins which stimulate the ovary?

4)      What is menopause or cessation?

5)      At which age generally menopause occurs?

6)      What are the different changes which took place during menopause?

7)      Which type of animals show menstrual cycle?

8)      What is the duration of menstrual cycle?

9)      How days are numbered in menstrual cycle?

10)   Name the organs which show periodic changes during menstrual cycle.

11)    What is the role of FSH in menstrual cycle?

12)    What is the role of LH in menstrual cycle?

13)   What are the terms applied to menstrual phase?

14)   What is the physiological reason of menstruation?

15)   What are the different components of menstrual flow?

16)   How much blood is lost during menstrual flow?

17)   Why the terms like ‘weeping of uterus’ or ‘funeral of unfertilized egg’ applied to menstrual phase?

18)   What is the stimulus for secretion of FSH at the end of menstruation?

19)   What is the thickness of basal part of endometrium?

20)  What is the duration of proliferative/follicular/repairy phase?

21)   What is germ hill?

22)  What are the different terms applied to germ hill?

23)  What is the position of ovum during follicular phase?

24)  What is corona radiata?

25)  What is zona pellucid?

26)  Which two layers of ovum are developed by stroma of ovary?

27)  How many follicles attain maturity at the end of second or proliferative phase?

28)  Which hormone stimulates endometrial glands?

29)  What is the final thickness attended by endometrium?

30)  Which is the shortest phase of menstrual cycle and what is its duration?

31)   What is ovulation?

32)  Which hormone stimulates the process of ovulation?

33)  Where ovum is released from the ovary?

34)  In which stage of cell division ovum is released?

35)  Name the site at which ovum is released from ovary.

36)  What is the viability period of ovum?

37)  When fertilized ovum reaches uterus after ovulation?

38)  When does implantation occurs?

39)  What is the fate of ovum in the absence of fertilization?

40)  Which is the last phase of menstrual cycle?

41)   What is the duration of luteal phase/secretory phase?

42)  What is the fate of ruptured follicle?

43)  Name the temporary endocrine gland produced in luteal phase.

44)  Which hormones control progesterone secretion?

45)  Why progesterone is called as pregnancy hormone?

46)  Which hormone is secreted by placenta?

47)  Which hormone resembles LH in function?

48)  Why abortion occurs?

49)  What is the fate of corpus luteum in the absence of fertilization?

50)  What is corpus albicans?

51)   What is the size and life span of corpus luteum?

52)  Which is the first indication of pregnancy?

53)  What is the effect of progesterone on endometrium?

54)  What is uterine milk?

55)  Where does embryo implanted?

56)  Presence of which hormone is detected in urine of pregnant woman?