Question

explain the mechanism of breathing?

Answer 1

Answer:-

★ Mechanism of breathing:-

→ It involves 2 steps:-

• Inhalation/Inspection.
• Exhalation/Expiration.

★ Inhalation/Inspiration:-

→ The process of intake of fresh air (oxygenated) is called as Inhalation or Inspiration.

→ During inspiration external intercostal muscles and phrenic muscles of diaphragm undergo contraction and Internal intercostal muscles undergo relaxation.

→ The ribcage lift upwards and diaphragm becomes flattened.

→ The volume of thoracic cavity increases and intra pulmonary pressure decreases.

→ The atmospheric fresh air easily diffuses into our body, the entire mechanism is known as inspiration or Inhalation.

★ Exhalation/Expiration:-

→ The process of giving out of foul air (deoxygenated) is called as Inhalation or Inspiration.

→ During expiration external intercostal muscles and phrenic muscles of diaphragm undergo relaxation and Internal intercostal muscles undergo contraction.

→ The ribcage pulled downwards and diaphragm becomes dome shaped.

→ The volume of thoracic cavity decreases and intra pulmonary pressure increases.

→ The foul air diffuses into or goes out of our body.

Answer 2

When we inhale air, it passes through our nostrils into the nasal cavity and then reaches the lungs  through the windpipe. Lungs are present in the chest cavity. This cavity is surrounded by ribs on the  sides. A large, muscular sheet called diaphragm forms the floor of the chest cavity. Breathing  involves the movement of the diaphragm and the rib cage.  During inhalation, ribs move up and outwards and diaphragm moves down. This increases the space  in our chest cavity and air rushes into the lungs. The exchange of gases takes place in the lungs.  During exhalation, ribs move down and inwards, while diaphragm moves up to its former position.  This reduces the size of the chest cavity and air is pushed out of the lungs.