Question

How does exchange of gasses take place in the human body?

Answer 1

Process of respiration in humans:

1. Respiration is the process of taking in oxygen and expelling out carbon dioxide.
2. Respiration in humans occurs in three phases - External, internal and cellular respiration.

External respiration:

1. External respiration refers to the exchange of gasses - oxygen and carbon dioxide, which occurs between the air and blood in the alveoli of the lungs.
2. During the external respiration, oxygen binds to haemoglobin in alveoli forming a temporary compound called oxyhaemoglobin and gets transported to various parts of the body.

Internal respiration:

1. Internal respiration is the process of gaseous exchange between blood and body cells.
2. During this process, oxygen enters the cells from the blood, whereas carbon dioxide enters the blood from the cells.

Cellular respiration:

1. Cellular respiration is the process by which oxygen entering the cell is used to break down glucose to release carbon dioxide, water vapor and energy.