4. Menstrual Cycle

1

The menstrual cycle is a monthly cycle of

changes in the female reproductive system

2

It is the way the uterus changes before and after the egg cell is released

The average menstrual cycle is 28 days but may vary from 20 to 40 days

3

It includes the maturing of the egg cell and preparation of the uterus to receive

a fertilized egg

Day 1 is the day external bleeding begins

4

This bleeding lasts an average of 5 to 7 days

The bleeding is the lining of the uterus being cleaned-out

5

By shedding and discharging the blood vessels not needed since the egg cell

was not fertilized

A new egg begins maturing in the ovary from days 8 to 13

6

Then on day 14 ovulation begins

7

Vocabulary:

ovulation

The release of an egg cell from the ovary

The egg cell will travel along an oviduct called the Fallopian Tube

8

This trip lasts about 3 days and is the time for pregnancy to occur

If sperm is available, the egg cell can be fertilized immediately upon release

from the ovary

9

Or could take a few days before fertilization

The egg cell continues from the Fallopian Tube to the uterus

10

If the egg cell has been fertilized then it will embed into the lining of the uterus

If the egg cell is not fertilized then it will die

11

The lining of the uterus will begin to release from the uterus to begin the

period again

Menstruation occurs when the girl’s reproductive organs mature

12

This occurs around the age of 9 to 16 and will last until about 45 to 55 years

of age

Late in menstruation there will be a gradual reduction of ovulation

13

Which could only occur every 2 or 3 months at a time until it stops

completely

Menopause is when the menstrual cycle becomes irregular and eventually stops

14

When menstruation stops, pregnancy can no longer occur