physiology – the study of how living organisms work

Note: Anatomy focuses on the size, shape and the location of the body structures in living organisms whereas physiology is the study of how these parts work. 

To remember the meaning of physiology, use the following mnemonic:

I drank lots of fizzy drinks and then the biology (physiology) student studied if all my body parts still worked. 

Physiology is the branch of biology that studies how living organisms and their parts function and work together to maintain life. Physiology examines the processes and mechanisms that allow organs, tissues, and cells to carry out their specific roles. In humans, this includes understanding how the heart pumps blood, how the lungs exchange gases, how the kidneys filter waste, how muscles contract, and how the nervous system coordinates responses to stimuli. 

Plant physiology involves studying processes like photosynthesis, transpiration, nutrient transport through xylem and phloem, and responses to environmental stimuli such as light and gravity. 

Understanding physiology is essential for explaining how organisms survive, grow, reproduce and respond to their environment, and it forms a basis for understanding health, disease and medical treatments.