Age 3 to 16
hope this helps
To avoid sun damage: Stay indoors between 10 a.m. and 2 p.m., when the sun’s burning rays are the strongest. Protect your skin with clothing, a hat, and sunscreen
Answer: Refractory period of the cardiac action potential
Explanation:
Unlike the skeletal muscle which can be reactivated before it reaches a contraction, cardiac muscle must wait before it is almost completely relaxed to be activated again (because of its long refractory period), so one cannot make an increase in strength of contraction with a high frequency of stimulations.
