🔘 Menstrual Cycle

Menstrual Cycle 

👉 DEFINITION OF MENSTRUATION :- 

- Menstruation is the visible menifestation of cyclic physiological  uterine bleeding due to shedding of the endometrium .

👉 Duration of Menstruation :- 4-5 days 

👉 Blood loos amount :- 30-80 Ml 

👉 COMPONENTS :- 

1) Dark altered blood 

2) Mucus 

3) Vaginal epithelial cells 

4) Fragment of endometrium 

5) Prostaglandin 

6) Enzymes 

7) Bacteria 

👉 ENDOMETRIAL CYCLE :- 

- 1st day of bleeding is considered as 1st day of cycle .

4-Phases :- 

1) Stage of regeneration 

2) Stage of proliferation 

3) Secretary phase 

4) Menstrual phase 

1) Stage of regeneration :- 

- it's starts even before ceases of Menstruation & it's completed 2 days after end of Menstruation .

- the cubical epithelium , glands , vessels regenarate from the basal zone .

- Thickness is 2 MM

2) Stage of proliferation ( follicular stage ) :- 

- it extends from 5th to 6th day to 14th day .

- The proliferative changes occur due to rise in level of ovarian estrogen .

- thickness is 3-4 mm 

3) Secretary phase ( Luteal phase ) :- 

- It's begins on day 15 & ceases 5-6 day prior to Menstruation .

- changes due to combined effect of estrogen & progesterone liberated from the corpus luteum after ovulation .

- Thickness is 6-8 mm 

- prominent corkscrew - shaped glands & increase vascularity .

- Endometrial glands increase in size & exceeds thickness of endometrium .

- They secret thick viscous fluid containing glycogen .

- Blood vessels undergo armed spiralling . 

4) Menstrual phase :- 

- It's essential degeneration & casting of an endometrium prepare for a pregnancy .

- The flow stops as result of combined effect of prolonged vascontriction , mayometrial contraction & local aggregation of platelets with fibrin deposition them .

- If no embryo , the corpus luteum begins to disintegrate .

- progesterone level drop , uterine lining detaches , Menstruation can begin .

- Tissue , blood , unfertilized egg all discharge .

- It can take 3-7 days .

👉 OVARIAN CYCLE :- 

- Development & maturation of follicle ovulation & formation of corpus luteum & it's degeneration constitute an ovarian cycle .

4 phase :- 

1) recruitment of group of follicle .

2) selection of dominant follicle & maturation .

3) ovulation 

4) corpus luteum 

1) Recruitment of group of follicle :- 

- It's presumed that about 20 antral follicle proceed & develop in each cycle .

- The intial recruitment & growthof primordial follicle are not under control of any hormone after certain stage 2-5 mm in size the growth & differentiation of follicle are the control of FSH .

- The follicle are rescued by FSH at this stage they undergo atresia .

2) Selection of dominant follicle & maturation :- 

- one with highest antral concentration of estrogen.

- Androgen - estrogen  low 

- maximum receptor of FSH 

- fully mature grfian follicle just prior to ovulation means about 20 mm.

3) Ovulation :- 

- The follicular wall near the ovulation surface becomes thin .

- The stigma develops as a conical projection with penetrate the outer surface layer of ovary & persists for while 0.5 to 2 min as a thin membrane .

- The cumulus escapes out of the folical by a slow oozing process about 1-2 min.

- The stigma is soon closed by plug of plasma .

- ovulation occurs :- 

1) 10-12 hrs after LH peak 

2) 34-36 hrs after onset of LH surge 

3) 24-36 hrs after oestradiol peak 

- The combined LH / FSH mid-cycle surge is responsible for the final stage of Menstruation .

4) Corpus luteum :- 

- After ovulation the rupture grafian follicle develops into corpus luteum .

4 phases :- 

1) Proliferation 

2) Vascularization 

3) Maturation 

4) Regression 

1) Proliferation :- 

- the colour of corpus luteum at this stage is graish yellow colour .

2) Vascularization :- 

- Withing 24 hrs of rupture of follicle , small capillaries grow into granulosa layer 

3) Maturation :-

- By 4th luteal cell have attained the maximum size , thickness is 1-2 cm & yellowish in colour. 

4) Regression :- 

- on the day 22-23 of cycle , regression is occour