solve the CHAPTER MYSTERY

OUT OF STRIDE

Although a healthful diet and exercise contribute to maintaining a healthy body, a balance between the two is important. Lisa lost this balance, and the reactions from her endocrine system led to a disorder known as the female athlete triad. The triad consists of three factors:

• Disordered Eating During her quest to become a faster runner, Lisa did not provide her body with enough nutrients and energy to support all of its functions.

• Amenorrhea Lack of menstrual cycles for three or more months is called amenorrhea. Lisa's hypothalamus responded to low energy levels by not signaling the pituitary to release FSH and LH. As a result, her menstrual cycle ceased and estrogen levels dropped.

• Weakened Bones Lisa's bones lost more calcium than normal because of high cortisol and low estrogen levels. This calcium loss, along with the low-calcium levels from her poor diet, led to weakened bones, which are at risk for stress fractures.

The problems associated with the female ­athlete triad are related to inadequate nutrition. Lisa used more energy and nutrients than she took in. The reaction of her endocrine system was normal, but it had negative effects on her health.

1. Relate Cause and Effect Explain why the menstrual cycle cannot continue without FSH and LH.

2. Sequence Make a flowchart to describe the factors of the female athlete triad.

3. Infer Why do you think that women who have gone through menopause are at risk for osteoporosis—a weakening of the bones due to calcium loss?

4. Connect to the Explain the three factors that led to Lisa's weakened bones. In a paragraph, propose ways Lisa can prevent this from happening again.