Menstrual Cycle
Trinity Ellis
Definition
The 28 day cycle that occurs when an egg is not fertilized. This causes the endometrium to shed, causing menstruation.
4 Stages of Menstrual Cycle
Follicle Stage
FSH is secreted from the anterior lobe of the pituitary gland on day 5 of the menstrual cycle. This matures one egg, then causes the endometrium to prepare inside the uterus. This lasts about 10 days.
Ovulation Stage
When the concentration of estrogen become high, the pituitary gland to stop making FSH. LH is then secreted by the gland. Around day 14, these hormones cause the follicle to break, causing ovulation.
Corpus Luteum Stage
After ovulation LH causes one of the ruptured follicles to divide quickly. This mass of cells is called corpus luteum. This in turn produces progesterone. This maintain growth and thickens the endometrium so if an embryo is implanted, the pregnancy can be maintained. This lasts about 14 days
Menstruation stage
If fertilization does not occur, The progesterone prevents LH levels from rising. This causes the corpus luteum to break down, lowering progesterone levels to lower. The lining becomes thinner and breaks down. The endometrium, unfertilized egg, and blood from the ruptured capillaries then is discharged through the vagina. This usually happens on the 28th day and lasts about 4 days.
Amenorrhea
The absence of a menstrual cycle due to pregnancy, anorexia, psychological factors, or hormone imbalances.
Premenstrual Syndrome
A group of symptoms shown prior to the menstrual cycle due to water retention in the body. Causes irritability, nervousness, mood swings, and weight gain.
Dysmenorrhea
Painful menstruation caused by an excessive production of an inflammatory substance, causing cramps.
Menopause
Also called "the change in life". This is a time in a female's life when the menstrual cycle comes to an end. This usually occurs around 45-55. This signals the end of follicle growth, ovulation, and the end of childbearing. This does not happen overnight, but happens over a few years. Some of the physiological changes are pronounced such as "hot flashes", dizziness, headache, rheumatic pain, and sweating. This can happen prematurely by removal of ovarian tissue.