Human Reproduction (Part 3 - Menstrual cycle)

Question 1

Menstrual cycle defintion

Answer 1

Production and release of female gametes

Changes in the lining of the uterus

Question 2

Hormones in menstrual cycle

Answer 2

Controlled by two pituitary hormones (FSH and LH) and two ovarian hormones (oestrogen and progesterone)

Question 3

Menstrual cycle process

Answer 3

Pituitary gland starts releasing FSH
FSH - follicle to develop
- follicle to release oestrogen
Oestrogen - Endometrium thickens
- Inhibits the release of FSH
- Stimulates the release of LH
LH - Ovulation
- Corpus luteum to release progesterone
Progesterone - prevents endometrium breaking down
- Inhibits release of FSH and LH
Drop of progesterone levels - Causes endometrium breaking down

Question 4

Menstrual cycle Peaks of hormones

Answer 4

FSH - Day 2,3 - Early in the first half
Oestrogen - Day 11, 12 - Late in the first half
LH - Day 14 - Half way point
Progesterone Day 22, 23 - During second half

Question 5

How to know if pregnant

Answer 5

Progesterone levels stay high at the end of menstrual cycle i.e. They miss their period

Question 6

Disorder of menstrual cycle

Answer 6

Fibroids - Benign tumours of the muscular wall of the uterus
Cause: Unknown
Symptom: Longer, heavier menstrual bleeding, infertility
Prevention:No prevention
Treatment: Surgical removal