Question

Secretory phase of the human menstrual cycle is also called
a. Luteal phase and lasts for 6 days
b. Luteal phase and lasts for 13 days
c. Follicular phase and last for 13 days
d. Follicular phase and lasts for 6 days

Answer 1

The monthly cycle that is regulated by hormones results in shedding of the uterus lining which causes bleeding from the female body is called the menstrual cycle. It starts during puberty and continues until menopause.

Complete answer:
Secretory phase:
- The secretory phase of the menstrual cycle is also known as the luteal phase.
- This phase starts from the 14th day of the menstrual cycle (after ovulation) and continues up to menstruation.
- On the 14th day of menstruation, ovulation takes place. Ovulation is the process by which the ovary releases an egg from its follicle in presence of a high concentration of LH.
- After releasing the egg, the follicle is called a corpus luteum.
- Corpus luteum remains in the uterus for 2 weeks and starts releasing progesterone hormone.
- A high level of progesterone hormone and lower estrogen maintains the thickening of the uterus lining for possible pregnancy until the next menstruation.
- If fertilization occurs, the egg is implanted in the inner uterus lining.
- If fertilization fails to happen, progesterone starts to decrease.
- Lower progesterone stimulates the rupture of the uterine wall which will initiate a new cycle.

Hence, the correct answer is option (B).

Additional information:
Menstrual cycle comprises four stages, named menstruation, follicular phase, ovulatory phase, and secretory or luteal phase.
- In the menstruation lining of the uterus, ruptured bleeding started.
- The follicular phase starts from day one of the cycles and continues up to the 13th day. In this phase, FSH and LH stimulate the ovary to produce 5-20 follicles. High LH and FSH trigger the estrogen level.
- On the 14th day, the ovulatory phase starts. Within 2 days egg released from the follicle by estrogen concentration.
- After the ovulation secretory phase initiates and lasts up to the beginning of the next cycle.

Note: During the luteal phase or secretory phase, the endometrium of the uterus starts secreting some chemicals which will either involve in expected pregnancy or will take part in the breakdown of endometrium lining in the upcoming menstrual phase. Thus, this phase is named the secretory phase.