Question

The tissue respiration is also known as
(a) Inspiration
(b) External respiration
(c) Internal respiration
(d) Expiration

Answer 1

Hint: Tissue respiration is the exchange of oxygen and carbon dioxide between the cells of different tissues and the blood. This occurs at the cellular level and is not directly related to the respiratory system.

Complete answer:
Tissue respiration occurs internally where the oxygen carried by the blood and RBCs is exchanged with the carbon dioxide produced by the cells of various tissues. Hence, this process is also known as internal respiration.
Internal respiration is the process of diffusion of oxygen from the blood, into the interstitial or tissue fluid and then into the cells. Waste products of metabolism and carbon dioxide are also diffused back in the other direction, i.e. from the cells to the blood. Oxygen is released from the red blood cells in response to the oxygen concentration in the capillaries of blood vessels, which is usually low. This enables the exchange of gases and other necessary solutes during internal respiration between the plasma and the tissue fluid.

So, the correct answer is, ‘ Tissue respiration is also known as internal respiration.’

Note: Internal respiration occurs only in animals with a functional circulation system. Animals with gills or lungs take in oxygen and transport the oxygen-rich blood throughout the body and they transport carbon dioxide-rich blood from the tissues of the body back into the respiratory organs where they can be expelled. In unicellular organisms or multicellular organisms with less developed systems, internal respiration is not seen as a separate process.