The Menstrual Cycle

The Menstrual Cycle:

The menstrual cycle is a major step towards adulthood in girls. Onset of menstruation is marked by puberty.

  

Puberty:

Puberty or adolescence is the phase during which body becomes sexually mature. It’s different for girls and boys. In case of girls puberty starts at the age of 10 to 14 and in boys, 12 to 16. There are both physical and mental changes in body.

In girls, the first sign of puberty is enlargement of breasts. Other signs are appearance of pubic hair, armpit hair, and menstruation.

In boys, onset of puberty is marked by growth of testicles and penis, appearance of pubic and body hair, growth of muscles, deepening of voice, facial hair growth.

Both boys and girls may get acne. There is a rapid growth in height and weight of both of boys and girls, which is quite normal, that lasts for about 2 to 3 years. This brings the adult height close.

The Female Reproductive System:

The female reproductive system performs different functions. It produces the egg cell known as ova, for reproduction. It makes the ova suitable for fertilization. It also delivers the ova in the region of fertilization i.e. the fallopian tube.

The female reproductive system also secretes female sex hormone, estrogen and progesterone, to maintain the functionalities of the female reproductive system.

The female reproductive system consists of a pair of ovaries along with oviducts, vagina, cervix, uterus, and the external genitalia that are located in the pelvic region. These parts along with a pair of mammary glands that are integrated both functionally and structurally also support the process of ovulation, fertilization, birth and finally the child care.

Let us see the function of each labelled part above:

1.     Ovaries: The main organ of female reproductive system, a pair of ovaries. Ovaries are responsible for producing egg cells or ova. It is situated one on each side of lower abdomen. Each ovary measures about 2-4 cm in length and is connected to the uterus and pelvic region through ligaments.

2.     Labia majora: Larger lip-like external structures that cover and protect sexual structures.

3.     Labia minora: Smaller lip-like external structures found inside the labia majora. They provide protection for the clitoris and for the urethra and vaginal openings.

4.     Clitoris: Very sensitive sexual organ located in front of the vaginal opening. It contains thousands of sensory nerve endings and responds to sexual stimulation.

5.     Vagina: It is the fibrous, muscular canal leading from the cervix (opening of the uterus) to the external portion of the genital canal. It functions as a receptacle for male reproductive organ, penis, during sexual intercourse. It is the passage through which a female body gives birth to a child.

6.     Fallopian tubes: Fallopian tubes are a pair of muscular that extend from both the superior corner of uterus to the ovaries. This is the place in female body where fertilization takes place. After fertilization, the zygote is transported to the uterus by the ciliary muscles of the fallopian tube. The zygote is implanted in the uterus and hence develops as a baby.

And in case fertilization doesn’t occur, the unfertilized egg is also transported to the uterus, after which menstruation occurs.

7.     Uterus: It is a muscular, inverted-pear shaped internal organ, also called womb, responsible for carrying the fetus. It consists of three layers, perimetrium, myometrium, and endometrium.

The fertilized egg from the fallopian tube reaches here and gets implanted on the wall of uterus. The fetus is present in a fluid filled sac called amniotic sac, containing amniotic fluid, inside the uterus.

The uterus protects the fetus from physical injuries. It provides nutritional support, helping the fetus gain the nutrients from the mother, it needs for proper growth. It helps in removing the waste from the amniotic sac, helping to keep the fetal environment clean.

The Menstrual Cycle:

The menstrual cycle is the first step towards womanhood. Onset of menstruation is known as ‘Menarche’ i.e. when first menstruation occurs. Menstruation ends at the age of about 50 to 55 years, different for every woman. The termination of menstrual cycle is known as ‘Menopause’. After menopause a woman is not fertile.

Menstruation is monthly shedding of uterine layer and tissues along with blood that exists through the vagina. It usually lasts for about 3 to 7 days. It is a cycle of average 28 days, varies from female to female.

The common problems during menstruation are:

1.     Back pain

2.     Headache

3.     Abdominal cramp

4.     Pain in limbs

5.     Vomiting

6.     Stress

7.     Frequent mood swings

These are very common in girls. In some girls they occurs and in some they doesn’t.

Phases of Menstrual Cycle:

The day count of menstrual cycle begins on the first day of menstruation when vaginal bleeding starts. Generally, the length of menstrual cycle is considered as 28 days. There are four main phases of menstrual cycle.

They are:

1.     Menstrual Phase

2.     Follicular Phase

3.     Ovulation Phase

4.     Luteal Phase

1.  Menstrual Phase:

The menstrual phase usually lasts from Day 1 to Day 5. The following events occur during this phase:

·        The uterus sheds its inner lining, endometrium, soft tissue and blood vessels which exits the body through vagina in form of blood.

·        Blood loss of 10 mL to 80 mL in considered normal.

·        The female body may experience abdominal cramps, which is normal. These pain occurs due to the uterine contraction to expel the menstrual fluid.

2.  Follicular Phase:

This phase starts from Day 6 and remains up to Day 12. The following events occur during this phase:

·        The pituitary gland secretes a hormone, FSH (Follicle Stimulating Hormone) that stimulates the egg cells in the ovaries to grow.

·        One of these egg cells begins to mature in a sac-like-structure called follicle. It takes about 13 days for the egg cell to reach maturity.

·        While the egg cell matures, its follicle secretes a hormone that stimulates the uterus to develop a lining of blood vessels and soft tissue, endometrium.

3.  Ovulation Phase:

This phase is very crucial. It’s the time when the chances of conceiving a baby is highest. This phase lasts for only 2 to 3 days. It starts on Day 13 and ends on Day 15. The following events during this phase:

·        The pituitary gland secretes a hormone, Estrogen that causes the ovary to release the matured egg cell.

·        The released egg cell is swept into the fallopian tube by the cilia of the fimbriae. Fimbriae are finger like projections located at the end of the fallopian tube close to the ovaries and cilia are slender hair like projections on each Fimbria.

4.  Luteal Phase:

This phase begins on the 16th day and lasts till the end of the cycle. The following events occur during this phase:

·        The egg cell released during the ovulation phase stays in the fallopian tube for 24 hours.

·        If a sperm cell does not impregnate the egg cell within that time, the egg cell disintegrates and moves towards the uterus.

·        The hormone that causes the uterus to retain its endometrium gets used up by the end of the menstrual cycle. This causes the menstrual phase of the next cycle to begin.

 Some Menstrual Disorders:

1.     Abnormal uterine bleeding (AUB): In this disorder there is heavy menstrual bleeding, no menstrual bleeding (amenorrhea) or bleeding between periods (irregular menstrual bleeding)

          Heavy menstrual bleeding can be caused by:

a.  Hormonal imbalances

b.  Structural abnormalities in the uterus, such as polyps or fibroids

c.   Medical conditions

2.     Dysmenorrhea: It is a condition of painful menstrual periods.

3.     Premenstrual syndrome (PMS): It is a condition when a woman has physical or psychological problems associated with periods.

4.     Premenstrual dysphonic disorder (PMDD): It is a condition same as PMS, yet more severe than that.