Unit 2: Heart and Lungs.(Brief Article)

Background Bonus

Blood delivers necessary oxygen throughout the body. When arteries become blocked and blood cannot deliver the necessary oxygen to the heart or brain, a heart attack or stroke results.

The heart works hard. Every 24 hours, the heart beats more than 100,000 times, pumping 8,000 gallons of blood through 12,000 miles of veins, arteries, and capillaries. With each beat, about a half cup of blood is pumped through the heart's valves. The number of heartbeats decreases with age: The resting heart rate of a newborn is 130 to 150 beats per minute; of a 6-year-old, 100 to 130; of an 11-year-old, 70 to 100; of an adult, 60 to 80.

Unit Objectives

Students learn to

* identify how healthy hearts and lungs work;

* calculate their target heart rate for aerobic exercise;