Question

What is meant by cardiac reserve?

Answer 1

Hint: Heart is the organ in the human body that is responsible for the regulation and pumping of the blood in the body. Failure of it can cause one to lose his life. We all know that cardiac reserve relates to the pumping of the blood in the body of a person.

Complete answer-
The heart is a hollow, muscular organ, roughly of the size of one's fist, being 12 cm. It lies in a conical sac called pericardium. The latter consists of an inner serous pericardium and an outer fibrous pericardium. It is a double pump that contains two chambers, upper smaller auricle and lower larger ventricle.
Contraction of the heart is followed immediately by relaxation, but the latter is not followed at once by the next contraction. Before the next contractions take place, there is a resting or recovery period in which no activity is seen. The recovery period is about twice the contraction time in which the heat shows activity and does work.
Cardiac reserve refers to the difference in between the rate at which the heart pumps the blood and its maximum capacity for pumping blood at any given time. It can be 4 to 5 times greater than the resting value for a healthy person and it's measurement may be a health indicator for some medical conditions. Cardiac reserve can be measured in different ways from past many years. There are chances to make a non- invasive measurement of cardiac reserve.
A measurement of cardiac reserve can help to predict the likelihood of heart failure when indicated. It ranges from 0.27 to 5.65 W.

Note:
The heart keeps on beating throughout life without getting fatigue, because it rests for double the time it works. Interference with the conductance of excitation from the sin auricular node over the heart is called the heat block. The interference may be caused by some mechanical obstruction or degeneration of tissue due to some disease.