Question

What are the phases of the menstrual cycle? Indicate the changes in the ovary and uterus.

Answer 1

The four phases of the menstrual cycle are:

• Menstrual or Destructive phase
• Follicular or Proliferative phase
• Ovulatory phase
• Luteal or secretory phase.

Events of the menstrual cycle and changes in the ovary and changes in the uterus. 

Phase	Days	Changes in Ovary	Changes in Uterus	Hormonal changes
Menstrual phase	4 – 5 days	Development of primary follicles.	Breakdown of uterine endometrial lining leads to bleeding.	The decrease in progesterone and estrogen.
Follicular phase	6th – 13th day	Primary follicles grow to become fully mature Graafian follicles.	Endometrium regenerates through proliferation.	FSH and Oestrogen increase.
Ovulatory phase	14th day	The Graafian follicle ruptures, and releases the ovum (egg).	Increase in endometrial thickness.	LH peak.
Luteal phase	15th – 28th day	Emptied Graafian follicle develops into corpus luteum.	The endometrium is prepared for implantation if fertilization of the egg takes place if fertilization does not occur corpus luteum degenerates, uterine wall ruptures, bleeding starts, an unfertilized egg is expelled.	LH and FSH decrease, Corpus luteum produces progesterone, and its level increases followed by a decline if menstrual bleeding occurs.