Physiology of Menstruation:
Physiology of Menstruation:
In every month, a woman in the reproductive age group (12 to 45+ years) expels blood, tissue and some fluid from the uterus for 3 to 5 days. This phenomenon which is termed as menstruation is regulated by the ovary which in turn is under the control of the brain. The two ovaries are present on either side of the uterus and are connected to ft by tiny fallopian tubes. These reproductive organs are located very low down in the abdominal cavity.
Each ovary contains thousands of eggs which are pre- formed at the time of birth. Each egg is surrounded by layers of cells which nurture and protect it. This unit of the egg and the neighbouring cells is called the follicle. After a girl attains puberty, every month some of the follicles start growing in response to the secretions of the pituitary gland which is located deep in the brain.
How the Hormones control Menstruation
On the days of and following menstruation, the pituitary sends a messenger called FSH (Follicle Stimulating Hormone) to the ovary asking the follicles to grow and produce another messenger called estradiol. Of the several follicles which have started growing, one develops faster than the others, dominates over the others and continues growing while the others degenerate. After 10- 12 days, the estradiol secreted by the large follicles sends a message back to the brain asking it not to send FSH any more but to send LH (Luteinising hormone). LH restocks the production of estradiol by the ovary and stimulates it to produce progesterone. LH also causes the follicle to break open and release the entrapped egg (ovulation). This generally happens on the 14th day of the cycle (The first day of the cycle being the first day of menstruation).
After being released from the follicle, the egg enters the fallopian tube waiting to be fertilised by the spermatozoa. However, most of the time the egg does not find its mate and withers away. The ruptured follicle regresses to become the corpus luteum and continues producing progesterone for a few more days. Progesterone production continues if the woman has become pregnant but stops if she is has not conceived.
Development of the Uterine Bed
Both the hormones, estradiol and progesterone, produced by the ovary go to the uterus via the blood stream. Estradiol produced in the first half of the cycle leads to the proliferation of the cells lining the inner surface of the uterus. The progesterone produced in the latter half of the cycle transforms these cells of the uterus so that they thicken to form a soft bed on which the egg if fertilised gets embedded. If conception has not occurred, progesterone is no longer produced and therefore the uterine bed cannot be maintained. The uterine bed has no function and therefore it sheds away on the 28th day of the cycle in the form of menstrual bleeding.
The length of the normal rnenstrual cycle is 28 days but many women may normally have shorter or longer cycles. For many, the days of menstruation are days of sheer agony. They feel weak and have to bear with cramps, aches and pain. Some bleed excessively and for some the discharge is scanty. The length of the cycle may get altered. Some women also have to put up with premenstrual tension exhibited as headaches, irritability and heaviness in the abdomen. The causes for these disorders could be psychological, hormonal imbalance, weak muscles of the reproductive tract or diminished blood supply to the reproductive organs.
These disorders often hinder the day to day activities of these women. In the olden days, at least in India, women were asked to refrain from several activities on the days of menstruation. In this age, women cannot expect such privileges. Work - be it housework or office work has to be done!
The consumption of pain-killers is not advisable for these chronic problems. The pain-killer does not kill pain but reduces your sensitivity to pain. Practice of asanas not only enhances one's sensitivity but also helps in overcoming the problems associated with menstrual disorders.
Common Menstrual Disorders
Dysmenorrhoea - Painful menstruation Symptoms: Cramps and sharp abdominal pain just before or during menstruation. Often accompanied by Nausea, vomiting and increased bowel movements and headache. Causes: a) a decreased blood flow to the uterine muscles b) Production of substances (prostaglandins) by the body which causes painful contractions of the uterus.
Menorrhaqja - excessive discharge which leads to an excessive loss of blood and generalised weakness.
Polymenorrhea - short menstrual cycles Causes: Normally, the hormone progesterone produced by the ovary maintains the uterine bed before it starts shedding. In some women, the ovary does not produce enough progesterone and therefore there is premature shedding of the lining of the uterus. Thus, the length of the menstrual cycle is shortened.
Oligomenorrhoea - scanty discharge at the time of menstruation. Causes: It could be due to the underdevelopment of the uterus or insufficient hormone production by the ovaries.
Amenorrhoea - Cessation of menstruation. It is called primary amenorrhoea when a girl has never menstruated and secondary amenorrhoea when the woman has been menstruating earlier. The commonest cause of amenorrhoea is pregnancy. An abnormality in any of the endocrine glands can result in amenorrhoea.
Endometriosis - It is a condition where the tissue which is normally present in the inside of the uterus starts growing in other parts of the abdomen. This tissue responds to the hormones produced by the ovary and grows and shed like the uterine bed. The most common sites of endometriosis is around the ovaries. The patient suffers from severe pain, abdominal cramps depending upon the site where this tissue grows.
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