Respiration and Respiratory Organs
Respiration is simply defined as the exchange of oxygen and carbon dioxide into the body.
Or, It is an oxidative process in which oxygen is taken into the tissue (from lungs) to oxidize the food in order to release energy and carbon dioxide.
The released energy is utilized to perform various life activities.
The metabolic waste like CO2 is removed from the body through lungs.
The compounds oxidized in respiration are called respiratory substrates.
Respiration is categorized into two types on the basis of site of gaseous exchange:
i. External respiration- exchange of gases between lungs and blood. It is the process of absorption of oxygen and removal of carbon dioxide from the body through lungs.
ii. Internal respiration- exchange of gases between blood and cells. It is the process of utilization of oxygen to produce energy and carbon dioxide by oxidation of food material inside the cell.
Respiration is of two types on the basis of availability of oxygen:
i. Aerobic respiration: The process which consists external and internal respiration occurs in higher animals including human beings are called aerobic respiration.
ii. Anaerobic respiration: In some organisms (such as bacteria, fungi, parasitic worms), glucose can be broken down to produce energy without utilizing oxygen. This process is referred to as anaerobic respiration.
