Question

Exchange of gases take place through the
A. Wall of trachea and blood capillaries
B. Wall of alveoli and blood capillaries
C. Wall of pleura and diaphragm
D. Wall of alveoli and bronchioles

Answer 1

Hint: In blood capillaries and alveoli, exchange of oxygen for carbon dioxide also known by the name pulmonary exchange takes place. The process occurs between the capillaries and connective tissues of the respiration system. The blood enters the ventricles of the heart through the upper chamber of the atrium. The left atrium receives blood from the lungs, and the right atrium receives blood from the venous circulation.

Complete answer:
The right atrium holds deoxygenated blood coming from the superior vena cava, inferior vena cava, anterior cardiac veins and the smallest cardiac veins that are present in the coronary sinus part of the heart. The blood then flows through the pulmonary artery to the lungs where the exchange of gases takes place. Exchange of gases takes place via diffusion. After the gas is exchanged in the lungs, the left atrium receives oxygenated blood from the right-left pulmonary veins and pumps towards the left ventricle with the help of a mitral valve. Aorta is used for the transportation of the oxygenated blood throughout the body. Systole helps to move the blood to the ventricles that are received from the atria during the relaxation of the diastole.

Note: The alveoli and capillaries both have very thin walls that help in the exchange of gases. The capillaries then connect to veins that bring the oxygenated blood from the lungs to the heart.