Menstruation Cycle Flashcards
What is menstruation?
Menstruation is the periodic discharge of blood and fluid from the uterus, which occurs in a 28-day cycle.
What is the Luteal Phase of menstruation?
The Luteal Phase is the third and final phase of menstruation, lasting from Day 15 to 28, and is governed by progesterone released by the corpus luteum.
What is the Flow Phase of menstruation?
The Flow Phase is the first phase of menstruation, lasting an average of five days, and marked by the shedding of the endometrial lining.
What is the role of LH in the menstrual cycle?
LH (luteinizing hormone) plays a role in ovulation, as its peak triggers the release of an egg from the follicle.
What causes menstruation?
A decrease in sex hormones at the end of the monthly cycle, which leads to hormone withdrawal.
What is the role of HCG in the menstrual cycle?
HCG (human chorionic gonadotropin) is a hormone that indicates pregnancy, as its peak/spike/increase results in a positive pregnancy test.
What is ovulation?
Ovulation is the release of an egg into the fallopian tube, which occurs on Day 14 of the menstrual cycle.
What is the Follicular Phase of menstruation?
The Follicular Phase is the second phase of menstruation, lasting until ovulation, and is governed by estrogen released by the developing follicle.
What is LH and when does its levels surge?
LH is Luteinizing Hormone. Its levels surge just before ovulation, which triggers the release of the mature egg from the ovary.
What is GnRH and what does it do during the menstrual cycle?
GnRH is the Gonadotropin-Releasing Hormone, which regulates LH and FSH levels throughout the menstrual cycle.
Follicular phase: GnRH levels rise, causing the pituitary gland to release LH and FSH in order to stimulate follicular development.
After ovulation: GnRH levels decrease, causing a decrease in LH and FSH and leading to the breakdown of the corpus luteum (If pregnancy occurs, GnRH levels remain low, and the corpus luteum continues to produce progesterone)
What is estrogen and what does it do during the menstrual cycle?
Estrogen is a hormone that gradually rises during the follicular phase and causes the uterine lining to thicken.
The surge in estrogen that occurs before ovulation triggers LH to surge which leads to ovulation
After ovulation, estrogen levels continue to rise, along with progesterone, to maintain the uterine lining. If pregnancy doesn’t occur, estrogen levels decline, and cause the uterine lining to shed.
What is FSH and when do its levels drop?
FSH is Follicle-Stimulating Hormone. Its levels drop after ovulation due to the negative feedback effect of estrogen and progesterone.
What is progesterone and what does it do during the menstrual cycle?
Progesterone is a hormone that increases after ovulation during the luteal phase to thicken and maintain the uterine lining in anticipation of pregnancy.
If pregnancy does occur: progesterone levels continue to rise and support the growing embryo.
If pregnancy does NOT occur: the corpus luteum breaks down, and progesterone levels decrease, causing the uterine lining to shed.
