Internal respiration is a key process in human biology that involves the exchange of gases between the cells of the body and the blood. This process is also known by a number of alternative terms that refer to the same physiological function. These synonyms include cellular respiration, intracellular respiration, tissue respiration, and metabolic respiration. While these terms may have slightly different connotations in different contexts, they all describe the same basic process that takes place within living organisms. Understanding these different synonyms can help students and researchers better understand the complex processes that take place within the human body.