http://www.ck12.org Chapter 1. Human Biology
Some people think that the average length of a menstrual period is the same as the “normal” length. They assume
that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in
length. This is usually normal.
The average length of the cycle (time between menstrual periods) is about 28 days, but there is no “normal” cycle
length.
FIGURE 1.133
Some women experience cramping and
pain before and during menstruation.Vocabulary
- menstrual cycle: Series of changes in the reproductive system of mature females that repeats every month.
- menstruation: Process in which blood and other tissues from the lining of the uterus are shed and exit the
body. - uterus: Female reproductive organ where the baby develops until birth.
Summary
- The menstrual cycle is a monthly cycle of changes in the ovaries and uterus.
- During menstruation, blood and other tissues from the lining of the uterus are shed and exit the body.
Practice
Use the resource below to answer the questions that follow.
- Ovulation and the Menstrual Cycleat http://www.youtube.com/watch?v=WGJsrGmWeKE (4:06)
MEDIA
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