Question

(a) Draw a diagram of the cross-section of the human heart and label the following parts (i) Right ventricle
(ii) Aorta
(iii) Left atrium
(iv) Pulmonary arteries
b) Give reasons for the following :
(i) The muscular walls of ventricles are thicker than the walls of atria.
(ii) Arteries have thick elastic walls.


CBSE Class X Science LA (5 Marks)

Answer 1

Part (a) is in attachment.

(b) (i) As ventricle have to pump the blood into various organs, the muscular walls of ventricles are thicker than the walls of atria.

(ii) Since the blood emerges from the heart under high pressure, arteries have thick elastic walls.

Answer 2

Answer:

Explanation:

Part (a) is in attachment.

(b) (i) As ventricle have to pump the blood into various organs, the muscular walls of ventricles are thicker than the walls of atria.

(ii) Since the blood emerges from the heart under high pressure, arteries have thick elastic walls