All female reproductive system transit from a non-reproductive stage to a reproductive stage, then to a menopausal stage where there’s cessation of reproduction.
The reproductive stage is marked by puberty which comes with the development of breasts and menstruation.
Menstruation and Menstrual Cycle
Menstruation which is often called period is the monthly shedding of the endometrium (inner layer of the uterus) from the body through the vagina.
The menstrual cycle is a natural change that occurs in the female reproductive system and in most women, it occurs at a regular predictable pattern while for some others, it does not.
The menstrual cycle starts with menstruation and has an average length of 28 days which vary across all women. It is regulated by series of complex hormonal integrated activities in the body.
The hypothalamus is a small, central region of the brain which modulates the endocrine system through its connection with the pituitary gland.
It causes the pituitary gland to produce certain chemicals that causes the ovaries to release the female sex hormones oestrogen and progesterone.
In each menstrual cycle, an egg develops and is released from the ovaries on maturation. The inner lining of the uterus thickens and becomes enriched with nutrients in preparation for fertilization. If the eggs do not get fertilized, the endometrium sheds off during a menstrual period and the cycle starts again.
Phases of Menstrual Cycle Are;
- Menstrual phase
- Follicular phase
- Luteal phase
This is the bleeding phase and lasts for about 3 – 7 days. During the phase, there is shedding of the endometrial lining of the uterus through the vagina.
The shed off endometrium which is also known as the menses contains blood, endometrial cells (cells from the inner lining of the uterus) and mucus. The bleeding is usually heaviest on the first 2 days.
Symptoms of Menstrual Phase;
2. Mood swings
3. Lower back pain
6. Tender breasts
The follicular phase starts on the first day of menstruation and ends with ovulation. During this phase, the level of the hormone estrogen increases which causes the inner lining of the uterus to grow and become thickened in preparation for fertilization.
The hypothalamus stimulates the pituitary gland to release Follicle stimulating hormone (FSH).
The follicle stimulating hormone (FSH) acts on the ovaries to produce an average of 5 – 20 follicles a small cavity or sac. Each of these follicles contains an immature egg.
Only one of these follicles will mature into an egg while the rest are being reabsorbed into the body. On rare occasions, two of these follicles will mature into two eggs which lead to the development of twins when both of the eggs are fertilized. This can occur around the tenth 10th day of the menstrual cycle.
Ovulation is the release of a matured egg from the ovarian follicle. It occurs at about the fourteenth 14th day of the menstrual cycle.
Due to the rising level of estrogen in the follicular phase, the hypothalamus releases the gonadotrophin – releasing hormone acts on the pituitary gland which is stimulated to release luteinizing hormone (LH).
The Luteinzing hormone causes the release of the matured egg from the ovarian follicle.
The matured egg travels from the surface of the ovaries down to the uterus through the fallopian tube. This matured egg only lasts for about 24 hours after which it either gets fertilized or dissolved.
During this phase, women have the highest chance of becoming pregnant. Simply means you should be familiar with your female reproductive system and its phases.
Signs of Ovulation are;
1. Slight increase in the basal body temperature
2. Fertile cervical discharge, a cervical discharge that looks like a raw egg white, this helps the sperm swim up into the female reproductive system.
3. Breast tenderness
4. Ovulation pain
5. Increased sexual desire
The Luteal phase:
The luteal phase of the menstrual cycle takes place from about the 15th to 28th day of the menstrual cycle.
After the ovarian follicle might have released an egg and it must have travelled down into the uterus via the fallopian tube.
The ovarian follicle then turns into a yellow body filled with a mass of cells which is known as the corpus luteum.
The corpus luteum produces the female sex hormone progesterone due to the increasing level of the luteinizing hormone.
The progesterone maintains the thickened lining of the uterus thus expecting the arrival of a fertilized egg to be implanted.
If fertilization occurs, human chorionic gonadotropin (hCG) is produced by the placenta which helps to maintain the corpus luteum.
The corpus luteum in turn helps to keep producing an increased level of the hormone progesterone to maintain pregnancy. The hormone human chorionic gonadotropin (HCG) can be detected in a urine test for pregnancy.
If fertilization does not occur, the corpus luteum becomes inactive and dies. This reduces the level of estrogen and progesterone and the thickened lining of the uterus is shed which brings about the menstrual phase.