Menstrual Cycle

By Kate Duran

Menstrual Cycle

Definition:

The monthly cycle of changes in the ovaries and the lining of the uterus (endometrium), starting with the preparation of an egg for fertilization. When the follicle of the prepared egg in the ovary breaks, it is released for fertilization and ovulation occurs. Unless pregnancy occurs, the cycle ends with the shedding of part of the endometrium, which is menstruation. Although it is actually the end of the physical cycle, the first day of menstrual bleeding is designated as "day 1" of the menstrual cycle.


Signs and Symptoms:

  • Acne
  • Swollen or tender beasts
  • Feeling tired
  • Trouble sleeping
  • Upset stomach

Big image

The Four Stages

First Stage: Follicle Stage

During this stage, follicle-stimulating hormone (FSH) is secreted from the anterior lobe of the pituitary gland on day 5 of the menstrual cycle. FSH is then circulated to an ovary by the bloodstream. When it reaches an ovary, it will stimulate several follicles, but only one matures. As the one follicle grows, an egg cell also begins to mature inside it. It starts filling with fluid containing estrogen. Estrogen stimulates the endometrium. This prepares the uterus for the implantation of an embryo. This stage lasts about 10 days.


Second Stage: Ovulation Stage

When the concentration of estrogen in the female bloodstream reaches a high level, the pituitary gland stop FSH secretion. As this happens, the luteinizing hormone (LH) is secreted by the pituitary gland. As this point there are three different hormones in the female bloodstream. Around day 14 of the menstrual cycle, this hormonal combination stimulates the mature follicle to break. When the follicle ruptures a mature egg cell is released, this is called ovulation.


Third Stage: Corpus Luteum Stage/Luteal Phase

After ovulation, LH stimulates the cells of the ruptured follicle to divide to divide quickly. This mass of reddish-yellow cells is called the corpus luteum. The corpus luteum then secretes a hormone called progesterone. Progesterone helps to maintain the continued growth and thickening of the endometrium, in case an embryo is implanted into the uterine lining, so the pregnancy can be maintained. This stage lasts about 14 days,


Fourth Stage: Menstruation Stage

If fertilization doesn't occur and an embryo isn't implanted in the uterus, the progesterone reaches a level in the bloodstream that inhibits further LH secretion. With decreased LH secretion, the corpus luteum breaks down causing a decrease in progesterone secretion. As the level of progesterone decreases, the lining of the endometrium becomes thinner and eventually breaks down. The extra layers of the endometrium, the unfertilized egg, and a small quantity of blood are discharged from the female's body through the vagina. This causes menstrual blood flow, and it usually starts around day 28. The menstruation stages lasts about 4 days. The cycle then starts over.

Big image

Amenorrhea

What is it?

Amenorrhea is the absence of menstruation.


Why does it happen?

Amenorrhea can occur for a variety of reasons. Some are normal during the course of a woman's life, while others may be a side effect of medication or a sign of a medical problem. Women may experience amenorrhea for natural reasons during pregnancy, breast-feeding, and menopause.


Causes:

  • Most common cause is pregnancy
  • Problems with reproductive organs or with the glands that help regulate hormone levels


Symptoms:

  • Absence of menstrual periods
  • Milky nipple discharge
  • Hair loss
  • Headache

Dysmenorrhea

What is it?

Dysmenorrhea is the medical term for the painful cramps that may occur immediately before or during the menstrual period.


Why does it happen?

Menstrual cramps are caused by contractions in the uterus, which is a muscle. The uterus, the hollow, pear-shaped organ where a baby grows, contracts throughout a woman's menstrual cycle. If the uterus contracts too strongly, it can press against nearby blood vessels, cutting off the supply of oxygen to the muscle tissue of the uterus. Pain results when part of a muscle briefly loses its supply of oxygen.


Symptoms:

  • Main symptom is pain
  • Vomiting
  • Diarrhea
Big image

Premenstrual Syndrome (PMS)

What is it?

Premenstrual syndrome is a group of symptoms that occur in women, typically between ovulation and a period.


Why does it happen?

Exactly what causes premenstrual syndrome is unknown, but several factors may contribute to the condition such as:

  • Cyclic changes in hormones
  • Chemical changes in the brain
  • Depression


Symptoms:

  • Tension or anxiety
  • Depressed mood
  • Joint or muscle pain
  • Acne flare-ups
Big image

Menopause

What is it?

Menopause is defined as occurring 12 months after your last menstrual period and marks the end of menstrual cycles. Menopause can happen in your 40s or 50s.


Why does it happen?

Various reasons such as:

  • Natural decline of reproductive hormones.
  • Hysterectomy
  • Chemotherapy and radiation therapy
  • Primary ovarian insufficiency


Symptoms:

  • Irregular periods
  • Vaginal dryness
  • Hot flashes
  • Night sweats
  • Sleep problems
  • Mood changes
Big image