Question

In humans, the alveoli are the functioning units of external respiration?
(a)True
(b)False

Answer 1

Alveoli are involved in the exchange of oxygen and carbon dioxide between the external atmosphere and body. This is commonly called as breathing and scientists describe it as Ventilation.

Complete answer:
Exchange of oxygen from air or water with carbon dioxide by the cells at the same time. This process is called ‘Breathing’, Scientists describe this process as ‘external respiration’ or ‘ventilation’. Alveoli are the structures present in the lungs that help in the exchange of oxygen and carbon dioxide.

Additional Information: Oxygen from the air enters into the body through nostrils and enters into the lungs via Naso-pharynx, Larynx, Trachea, Bronchi, and Bronchioles.
- In the lungs, Alveoli are present that help in the exchange of gases.
- The carbon dioxide produced inside the body is exchanged with the external atmosphere and is also via the same passage.
- This is considered as external respiration or ventilation.
- Breakdown of food materials that provide energy for life is called respiration. As this process occurs inside the body i.e., in the cells, it is considered as internal respiration.
- It is also called cellular respiration.
- In cellular respiration, carbon dioxide is produced after the utilization of oxygen and this carbon dioxide is carried to the alveoli of the lungs via blood.
So, the correct answer is ‘True”.

Note: -In respiration, the parts starting from external nostrils to bronchioles in lungs are considered as conducting parts, and alveoli and their ducts are called the respiratory part or exchange part.
-Passage of gases: external nostrils, nasopharynx, larynx, trachea, bronchi, bronchioles, and alveoli.