What is the definition of a heart contraction? Is it when the heart relaxes or when it squeezes and pushes the blood from one place to another?
Hint: The heart is a muscular organ present in most upper organisms. The heart pumps blood to all the organs of the body using the blood vessels as a medium for carrying the blood.
Complete answer: The human heart is divided into four compartments. They are as follows: 1. Right Atrium 2. Left Atrium 3. Right Ventricle 4. Left Ventricle The atria are located above the ventricles. The cardiac cycle is the activity of the heart beginning from one heartbeat till the beginning of the next heartbeat. The cardiac cycle of the heart consists of two phases, the phase of relaxation of the cardiac muscles of the heart called diastole where blood is refilled in the cardiac muscles. The diastole is followed by the contracting phase of the heart called systole where the contraction of the heart muscles pumps the blood throughout the body. The heart immediately expands after contracting and pumping the blood throughout the body and is ready to repeat the cycle.
Thus, a heart contraction is the squeezing of the heart muscles for the purpose of pumping blood all over the body.
Note: The blood pumped by the heart carries oxygen and nutrients to all parts of the body. The blood also carries metabolic waste in the form of carbon dioxide to the lungs. The human heart is approximately the size of a closed fist. The heart is located in the middle compartment of the chest, between the lungs.