Explain the menstrual cycle in human females.

The menstrual cycle is a natural, recurring process that occurs in the reproductive system of human females. It is controlled by a complex interplay of hormones and involves a series of changes in the ovaries and the uterus. The cycle typically lasts about 28 days, although variations are common.

Here is a breakdown of the menstrual cycle:

Menstruation (Days 1-5):

The cycle begins with menstruation, commonly known as a period.
The lining of the uterus, which had thickened in preparation for a potential pregnancy, is shed and expelled through the vagina.
This phase usually lasts around 3 to 7 days.
Follicular Phase (Days 1-13):

Concurrently with menstruation, the brain's pituitary gland releases follicle-stimulating hormone (FSH).
FSH stimulates the development of several ovarian follicles, each containing an immature egg.
Only one of these follicles becomes dominant and continues to mature, while the others degenerate.
Ovulation (Day 14):

Around the middle of the menstrual cycle, a surge in luteinizing hormone (LH) triggers the release of the mature egg from the dominant follicle.
This release of the egg is known as ovulation and typically occurs around day 14 of a 28-day cycle.
The egg moves into the fallopian tube, where it is available for fertilization by sperm.
Luteal Phase (Days 15-28):

After ovulation, the ruptured follicle transforms into a structure called the corpus luteum.
The corpus luteum secretes progesterone, which helps prepare the uterine lining for a potential pregnancy.
If fertilization and implantation of a fertilized egg do not occur, the corpus luteum breaks down, leading to a drop in progesterone levels.
This decline in hormones triggers the start of menstruation, and the cycle begins anew.
If fertilization occurs, the developing embryo releases signals to maintain the corpus luteum, and pregnancy proceeds.

It's important to note that the length and regularity of menstrual cycles can vary among individuals. Factors such as stress, diet, and overall health can influence the menstrual cycle. Tracking the menstrual cycle can be useful for family planning and reproductive health monitoring.