Match the following. Column A Column B 1. Oxygen a. 0.85 sec 2. Carbon dioxide-rich air b. 72 times per minute 3. Heartbeat c. Exhalation 4. Polio d. Inhalation 5. Pulse e. Virus

1-d Breathing is the process of inhaling oxygen-rich air and exhaling carbon dioxide-rich air. While inhalation, the diaphragm moves down and becomes flat due to contraction. 2-c Breathing is the process of inhaling oxygen-rich air and exhaling carbon dioxide-rich air. While exhalation, there is an increase of pressure in the chest cavity that forces the carbon dioxide along with some water vapour to move out of the lungs. 3-b Our heart is the organ of circulatory system that pumps blood to parts of the body through blood vessels. A full heartbeat in human beings lasts for about 0.85 seconds. 4-e Polio is a communicable disease caused by a virus. It can be prevented by taking the polio vaccine. 5-a The rhythmic beating of arteries due to the beating of the heart is called pulse. Our heart beats about 72 times per minute. Column A Column B 1. Oxygen-rich air d. Inhalation 2. Carbon dioxide-rich air c. Exhalation 3. Heartbeat b. 72 times per minute 4. Polio e. Virus 5. Pulse a. 0.85 sec

The taking in of air rich in oxygen into the body during breathing is called 'inhalation'. When we breathe in, then two things happen at the same time: (i) the muscles between the ribs contract causing the rib cage to move upward and outward, and (ii) the diaphragm contracts and moves downward. The upward and outward movement of rib cage, as well as the downward movement of diaphragm, both increase the space in the chest cavity and make it larger. As the chest cavity becomes larger, air is sucked in from outside into the lungs. The lungs get filled up with air and expand.

MEDIUM

Earn 100

Name any four organs that are involved in human respiration.

Important Questions on Movement

MEDIUM

Life Science>Change>Movement>Movement in Respiratory System

Match the following.

Column A	Column B
1. Oxygen	a. 0.85 sec
2. Carbon dioxide-rich air	b. 72 times per minute
3. Heartbeat	c. Exhalation
4. Polio	d. Inhalation
5. Pulse	e. Virus