Question

The figure given below shows the various events occurring during a menstrual cycle with few events marked as 1, 2, 3, 4 and 5. Which of the following options shows the correct events?  
     

A. 1 - LH, 2 - Ovulation, 3 - Menstruation, 4 - Proliferative phase, 5 - Luteal phase
B. 1 - FSH, 2 - Implantation, 3 ? Follicular phase, 4 - Menstruation phase, 5 - Luteal phase
C. 1 - Estrogen, 2 - Parturition, 3 - Luteal phase, 4 - Follicular phase, 5 - Follicular phase
D. 1 - Progesterone, 2 - Fertilisation, 3 - Menstruation phase, 4 - Secretory phase, 5 - Follicular phase

Answer 1

Hint: In the years between adolescence and menopause, a woman's body goes through a number of changes each month to prepare for a future pregnancy. This series of hormone-driven events is known as the menstrual cycle. The hormones are secreted by pitutary like LH and FSH and ovarian such as estrogen and progesterone. The cycle is mainly divided into different phases such as luteal phase, follicular phase and menstruation phase.

Complete step by step solution: Because the menstrual cycle is a biofeedback mechanism, the activity of one gland or function affects the functioning of all the others. The menstrual cycle typically lasts 28 to 29 days, though this might vary across women and from cycle to cycle. The first day of the phase to the day before the start of your next period is considered the start of your menstrual cycle.
The menstrual cycle is divided into four distinct periods. They are ovulation, the follicular phase, the luteal phase, and menstruation.
Menstruation: Menstruation is the process by which the vagina removes the thicker uterine lining from the body. Mucus, uterine lining cells, and blood are all components of menstrual fluid. The period typically lasts between three days and one week.
Follicular phase: The first day of menstruation marks the start of the follicular process, which ends with ovulation. The pituitary gland releases follicle-stimulating hormone, which is produced by the hypothalamus (FSH). The ovary is stimulated by the FSH hormone to produce five to twenty follicles that make up the top of the bead. An immature egg is produced by each follicle. The rest usually die, and just one follicle develops into an egg. This will take place on the tenth day of a cycle of 28 days. The uterine lining thickens as a result of follicular development in preparation for a future birth.
Ovulation: A developed egg is removed from the ovarian surface during ovulation. This typically takes place two weeks or so prior to the start of menstruation, in the middle of the cycle. The development of the follicle causes the level of oestrogen to rise during the follicular phase. When these levels rise, the brain's hypothalamus releases a hormone called gonadotropin-releasing hormone (GnRH). The pituitary gland is stimulated by this hormone to produce more luteinizing hormone (LH) and FSH. Ovulation occurs within two days as a result of an increase in LH. Waves of minuscule, hair-like projections eat the egg in the fallopian tube and towards the direction of the uterus. The typical egg has a 24-hour life cycle.
Luteal phase: After ovulation, the egg explodes from its follicle, but the injured follicle is still resting on the ovary's surface. The follicle transforms into the corpus luteum throughout the course of the following two weeks or so. Progesterone and negligible amounts of oestrogen are still released as a result of this arrangement. This hormonal combination protects the uterus' thicker lining and gets the fertilised egg ready to stick. The hormones needed to maintain the luteum of the corpus are released if the egg implant is fertilised in the uterine lining. This contains the hormone human chorionic gonadotropin (HCG), which is detected in the urine during a pregnancy test.

Hence, the correct option is A. 1 - LH, 2 - Ovulation, 3 - Menstruation, 4 - Proliferative phase, 5 - Luteal phase

Note: Mid-cycle, there is a rapid release of LH hormone, which causes LH surge and triggers the Graffian follicle to burst, releasing the ovum through ovulation. Only the egg emerges from the follicle during ovulation; the remaining burst follicle remains outside the ovary. Within fourteen days, the follicle transforms into the corpus luteum, a tissue that secretes progesterone and small amounts of oestrogen to maintain the uterine walls' thickening in preparation for implantation.