By Johana Moreno Andrea Slobodien

Also known as the Menstrual Cycle Recurring cycle of physiological changes that occur in reproductive-aged woman Overt Menstruation occurs primarily in humans Where the blood flow is from the vagina Menstrual Phases: Menstrual Phase Follicular Phase Ovulation Luteal Phase

1.Menstrual Phase The blood flow indicates that a woman is not pregnant The menstrual fluid is a mixture of blood and tissue from the uterine lining An enzyme, PLASMIN inhibits blood clotting 2.Follicular Phase Also known as the proliferative phase, he hormone causes the lining of the uterus to grow, proliferate, during this phase characterized by the development of the follicles within the ovary As the follicle cells develop, the hormone estrogen is secreted and its concentration increases The follicle that reaches maturity is called the OVUM

3.Ovulation estrogen levels decline and the egg bursts form the ovary and follicular cells differentiate into the corpus luteum 4.Luteal Phase Also known as the secretory phase Estrogen levels are restored as the corpus luteum develops Prepares the uterus to receive a fertilized egg as the corpus luteum releases both estrogen and progesterone – does 2 things 1.stimulates the endometrium and prepares the uterus for an embryo 2.Inhibits further ovulation and prevents uterine contractions – if progesterone levels fall, uterine contractions would begin If fertilization does not occur, the concentration of estrogen and progesterone drop, thereby causing weak uterine contractions – which, in turn, cause the endometrium to pull away from the uterine wall

IMBALANCES Abnormal Uterine Bleeding – Excessive heavy bleeding caused by hormonal imbalances, structural problems with uterus, medical conditions, fibroids (uterine tumors) Birth Control (Hormonal Contraceptive) – Most forms do not affect the menstrual cycle however it does disrupt the normal cycle and can make the period come more, or less, depending on the person. Menstrual Cramps – Prostaglandins – hormones that trigger menstrual cramps. More prostaglandins means more cramps. Oligoovulation – Irregular ovulation PMS and Premenstrual Dysphoric Disorder (10 times worse than PMS) – Caused by complex interaction of brain chemicals 7-10 days before the menstrual cycle begins.

IMBALANCES Amenorrhea – Cycle does not occur Pregnancy – The menstrual cycle does not occur during pregnancy Malnourishment – Can prolong or even delay periods Birth Control (Hormonal Contraceptive) – Can lessen the amount of times a period occurs in a year.

Homeostasis and Hormones Human Hemoglobin (Hb) and its derived peptides are vital to maintaining the host defense mechanism against vaginal pathogens Hb is antimicrobial and acts as an immunity against vaginal pathogens Maintaining a Nutrient Supply- Woman need iron to help regulate their period Conditions in the body are controlled resulting in a constant internal environment; Hormones are chemical secreted by glands they travel through the bloodstream and affect targeted organs Several hormones control the Menstrual Cycle: Estrogen, which causes the repair of the uterus wall Progesterone, which maintains the uterus wall

Both Estrogen and Progesterone are secreted by the ovaries. The graph above shows the change in level of both hormones during the menstrual cycle. If the woman becomes pregnant the progesterone level remain high.

The Menstrual Cycle itself is the body’s response to not being pregnant. The body’s response to heavy cycles is increased cramps (as a result of the increased hormone). The body’s response to iron deficiency, polyps, and imbalance of hormone levels (estrogen and progesterone) is increased bleeding. Estrogen and Progesterone regulate the lining of the uterus. In imbalance, the lining occurs in excess so there is more blood to shed.

Problems that arise Vaginal infects may occur if pathogens are not coped with Excessive menstrual loss is a direct cause of iron deficiency – Uterus would contract more resulting in painful and uncomfortable cramps (Dysmenorrhoea)

Having and enduring even ONE menstrual cycle is a sign of strength and thus, all women are inherently dominant. Humans undergo Overt Menstruation, meaning blood flows from the vagina. Menstruation is a response to not being pregnant, as the uterus lining and un-used egg is shed. Abnormalities in menstrual flow are often times the result of hormones, and our body responds by excessive bleeding.

QUESTIONS What kind of menstruation occurs primarily in humans? Which enzyme inhibits clotting? In Which stage of the MC does the egg burst form the ovary? Explain the role of estrogen in relation to the uterus wall? Why is maintaining homeostasis important in relation to the menstrual cycle? Which two hormones control the lining of the uterus? Name one cause of excessive bleeding. True or False: Iron deficiency leads to blood deficiency in menstrual cycle. What can artificially regulate one’s menstrual cycle? What is the body’s most common response to irregularity? (increased or decreased flow?)