Menstrual Cycle and The Female Reproductive Hormones

What is the Menstrual Cycle?

• a series of monthly hormonal changes causing ovulation and preparation of the uterus for a possible pregnancy

• usually lasts about 28 days long

• Controlled by the hypothalamus

How long does the menstrual cyle usually last?

28 days

What is menstrual cycle controlled by?

The Hypothalamus

What are the four stages of the Mentrual cycle

1. follicular stage

2. Ovulation

3. Luteal stage

4. Menstration

In the Follicular stage, what stimulates follicles to grow and release estrogen into the bloodstream?

FSH

The growth of follicles and release of estrogen into the bloodstream causes?

The endometrium to thicken & increase the blood supply, thus preparing for a possible pregnancy

The release of estrogen in the follicular stage inhibits ____ causing?

FSH causing a negative feedback loop, stimulating the hypothalamus to release large amounts of LH

Ovulation occurs at the?

midpoint of the cycle (Day 14)

The increase in LH causes?

the follicle to rupture and ovum is released

causing the follicle to change into the corpus luteum

How long does the luteal stage last for?

2 weeks

What does the corpus luteum produce?

produces Progesterone

the corpus luteum produces progesterone which inhibits ____?

the development of a new follicle.

also inhibits the production of LH causing the corpus luteum to degenerate and progeterone levels to decrease

Inhibiting the development of a new follice ensures?

another ovum is not released during the cycle and further prepares the endometrium for pregnancy.

How longs does menstration last for?

5 days

what happens when progesterone levels fail?

The blood supply to the endometrium decreases, thus causing it to break down

the tissues and blood flow out through the vagina