Question

Read the graph given below and correlated the uterine events that take place according to the hormonal levels on
(i) $6-15$ days
(ii) $16-25$ days
(iii) $26-28$ days (if the ovum is not fertilised)

Answer 1

• 6-15 days: If the egg is not fertilized then the menstrual cycle continues for another 14-15 days (the secretory phase). This period is usually the same length, regardless of the total length of the woman's menstrual cycle. Levels of estrogen, progesterone, luteinizing hormone and follicle stimulating hormone all decline.

• 16-25 days: The ovulation occur during this phase and the progesterone level rises.

• 26-28 days: If the ovum is not fertilized then the progesterone and estrogen level falls which leads to the degeneration of the ovarian wall. Due which mensuration cycle takes place.