During contraction of heart, what prevents backflow of blood?
Answers
Answer:
Explanation:
The heart is made up of four chambers. The chambers on the right side of the heart are the right atrium and right ventricle.
The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava (major veins).
The blood then flows to the right ventricle where it is then pumped, via the pulmonary circuit, through the pulmonary artery to the lungs for gaseous exchange (CO2 out, O2 in).
The chambers on the left side of the heart are the left atrium and left ventricle. The left atrium receives oxygenated blood from the lungs via the pulmonary veins.
The blood then flows to the left ventricle where it is then pumped, via the systemic circuit, through the aorta and then pumped out to the to the organs and tissues of the body to supply them with oxygen and nutrients, and pick up waste products for expulsion.
Answer:
During the contraction of the atria, the blood flows into the ventricles which are in diastole. But when the ventricles begin to contract, the blood tries to flow backwards, which is prevented by the atrio-ventricular valves. On the right side of the heart, the papillary muscles have projections called chordae tendinae which hold the three cusps of the valve in place which is called the tricuspid valve. on the left side, there is a similar arrangement except it is called biscuspid valve with two cusps. When the ventricles start to relax, the blood which has gone into the pulmonary artery from the right ventricle and aorta from left ventricle tries to come back into the ventricles, However, the pulmonary semi-lunar valve and the aortic semi-lunar valve prevent the back flow.
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Explanation: