Question

The secretory phase in the human menstrual cycle is also called as
A. Luteal phase and last for about 6 days
B. Follicular phase lasting for about 6 days
C. Luteal phase and last for about 13 days
D. Follicular phase and last for about 13 days

Answer 1

Menstruation is a natural hormonal process that occurs as a part of a woman's monthly cycle to prepare for a possible pregnancy. It involves the bleeding of vagina and this blood is composed of blood and tissue from the uterus.

Complete answer:
Menstrual cycle begins with the menstrual flow (menses), followed by follicular phase. This phase is also called a proliferative phase which lasts for about day 6 to 14. Then after ovulation, the next phase of the human menstrual cycle is referred to as the luteal phase. During this stage, the remaining part of Graafian follicle is converted into corpus luteum which secretes progesterone hormone and this phase lasts for about 13-14 days in case of absence of pregnancy. Hence, this luteal phase in the menstrual cycle is also called the secretory phase.

Hence, the correct answer is option (C).

Additional information:
The menstrual cycle is controlled by various endocrine glands and it is regulated by the complex interaction of several hormones: luteinizing hormone (LH), follicle-stimulating hormone (FSH), and the female sex hormones: estrogen and progesterone.
The menstrual cycle is categorized under four phases, namely:
Menstrual phase: shedding of the thickened lining of the uterus (endometrium) from the body through the vagina. The menstrual period begins with menstrual bleeding which typically lasts for day 3 to 5.
Follicular phase (before the egg release): During this phase, the increase in the level of estrogen hormone makes the endometrium grow thicker. At the same time, FSH prepares the follicles in the ovaries to grow to form a fully matured egg. This period is also known as a proliferative phase and it takes place from day 6 – 14.
Ovulatory phase (egg release): It is referred as Mid-cycle phase, in which it occurs roughly on the day 14 of a 28-day menstrual cycle and lasts for about 24 hours. During this phase, LH stimulates the ovary to release its egg. This particular event is known as ovulation. The estrogen level starts to decrease, and there is a gradual increase in the level of progesterone.
Luteal phase (after the release of egg): In the postovulatory phase, the closure of ruptured follicle after the egg release and the decrease in the level of LH and FSH, forms a corpus luteum, which secretes progesterone hormone. The level of the progesterone hormone rises up to maintain the thickness in the lining of the uterus for possible fertilization. The Luteal phase is also referred as secretory phase, which lasts for about 13 days i.e., from day 15 to 28 of 28 days menstrual cycle.
If fertilization doesn’t occur, corpus luteum degenerates and estrogen and progesterone levels drop which makes the thickened endometrium to break down. Thus it marks the onset of another menstrual cycle.

Note: Menstrual cycle took place throughout the woman's reproductive life, except at the time of pregnancy. The menstrual cycle starts at the time of puberty known as menarche and stops permanently at menopause stage.