Question

What happens when you breathe out?
a. The diaphragm expands and the chest contracts.
b. The diaphragm contracts and the chest expands.
C. The diaphragm relaxes and your chest returns to its
original size.
d. The diaphragm does not move and your chest
expands​

Answer 1

Answer:

the correct answer is a. Believe me I am a true army.. Please mark me as Brainlist..

Answer 2

✯ANSWER:-

Option C The diaphragm relaxes and your chest returns to its

✯EXPLANATION:-

• When we breathe out, the muscles between the ribs relax, and the ribs and the breastbone return to their original positions.

• The diaphragm also relaxes and become dome-shaped.

• As a result, the volume of the chest cavity decreases. This increase the pressure inside the lungs and forces the air out of the lungs.

◉LET'S EXPLORE MORE

✯EXTERNAL RESPIRATION IN HUMANS

The main Organs of Respiration in Humans are the lungs.

• Air is drawn into the nostrils during breathing, dust particles are trapped by hair in the nostrils. and clean air go through nostrils.

• The clean air now passes through the pharynx into the windpipe or trachea, and then it passes through bronchi ( singular: bronchus.

• Each bronchus enters lungs. the two lungs are sponge like structure. they are protected by ribcage. At bottom of the chest cavity is a dome-shaped muscle called Diaphragm.

• In the lungs, the bronchi branch into smaller tubes called bronchioles.

• Lungs are composed of millions of air sacs called alveoli. which are present at end of bronchioles.

• The path of air in the Respiratory System is shown as:

nostrils→pharynx→trachea→bronchi→bronchioles→alveoli

Air enters and the lungs through the process of inhalation and exhalation.

☆Inhalation

• The process of breathing in air is called inhalation.

• During Inhalation, the muscles present between the ribs contract and move the ribs upwards and outwards.

• The diaphragm contracts and become flat. The breastbone moves outwards.

• As a result the volume of the chest cavity increases. This lowers the pressure in the lungs and the air from outside the body flows into lungs.

☆Exhalation

• The process of breathing out air is called exhalation.

• During exhalation,the muscles between the ribs relax, and the ribs and the breastbone return to their original positions.

• The diaphragm also relaxes and become dome-shaped.

• As a result, the volume of the chest cavity decreases. This increase the pressure inside the lungs and forces the air out of the lungs.