He noises your stomach makes, called borborygmi, are normal intestinal sounds that occur during the digestive process.
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.
The items that can contribute to heart disease is C. Nitrogen oxides and carbon monoxide. These are the chemicals that contribute to pollution. Carbon monoxide is the product from a combustion that can affect our respiratory system whenever we inhale this gaseous chemical. And nitrogen oxides can affect and penetrate areas of the body when inhaled in which our respiratory organs may be affected by diseases because of this chemical.
