Question

(a) Which chamber of the heart (6, 7, 8 or 9) pumps blood to the lungs for oxygenation, name it? Identify and name the blood vessels that carry blood to the lungs.

(b) Identify the structure at number 12 and state its function.

(c) Why do chambers 6 and 7 have thicker muscular walls than chambers 8 and 9? Name each of these chambers.

OR

(i) Identify and name the chamber that receives oxygen rich blood and name the blood vessels which bring it.

(ii) State the significance of separation of right and left side of heart as seen in the above figure.

Answer 1

(a) 7. Right ventricle, 2. Pulmonary arteries

(b) Valves - They ensure that blood does not flow backwards when atria or ventricles contract.

(c) Left and right Ventricles (6 and 7) have thicker walls as compared to left and right atria (8 and 9). They have to pump blood out of the heart. They pump blood at a higher pressure to ensure it reaches all parts of the body.

OR

(i) 8. Left atrium, 3. pulmonary veins

(ii) The separation of the right and left side of the heart is useful to prevent mixing of oxygenated blood and deoxygenated blood.