The term refers to the alternating surges of pressure in an artery that occur with each contraction and relaxation of the left ventricle.

The term pulse refers to the alternating surges of pressure in an artery that occur with each contraction and relaxation of the left ventricle.

Explanation:

The heart is an organ that has the function of pumping blood to the body through the arteries. The right atrium receives the blood that is sent to the lungs through the right ventricle. In the lungs, the blood is oxygenated. Then, the oxygenated blood is received by the left atrium and is sent through the left ventricle to the rest of the organism. This cycle is repeated constantly between 70 and 80 times per minute which determines the heart rate. Each time the heart ejects blood and it circulates through the arteries the way to feel or perceive it is by palpating the pulse.

The pulse is then the pressure wave caused by the expansion of the arteries as a result of the circulation of blood pumped by the heart. It is usually obtained in parts of the body where the arteries are closest to the skin, such as in the wrists or neck.

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.