Activities
The heart is made of muscle which contracts rhythmically to produce the heartbeat, roughly 70 times a minute. In an average lifetime the human heart beats approximately two and a half billion times, without pausing!
a) Lay your hand, palm side up, on your desk and count how many times you can open and close your hand in two minutes.
Number of hand closures in two minutes =
Number of hand closures per minute =
b) How does the number of times you can contract the muscles of the hand in one minute compare with the 70 contractions per minute of the heart? Describe how your hand felt after just two minutes of muscle contractions.
c) Find out how heart muscle is different from skeletal muscle. Explain why skeletal muscle could not be used to replace heart muscle.
