Physiology

Physiology is the scientific study of the functions of the human body - how its parts and systems operate. For a student of physical education it can be put more sharply still: physiology is the study of the responses of the human body to physical activity.

Where the word comes from

The word physiology comes from the Greek physio, meaning nature, and logio, meaning the study of. Physiology covers the detailed functioning of the body and its parts, and the way the body responds to a given stimulus. You can see it at work in everyday actions: when we walk, the body and its parts work together in a synchronised way; and throughout, the heart is continuously working to supply oxygen and nutrients to the cells. In the broadest sense, physiology is the detailed study of life itself, including the functioning of the smallest cells, of tissues and of whole organisms.

Sub-branches of physiology

Physiology is further divided into:

• Human physiology - the study of the functioning of a specific organism, namely the human being.
• Cellular and systemic physiology - cellular physiology is the study of how cells function, while systemic physiology is the study of how the body's systems function.
• Exercise physiology - the branch most relevant to this course. It studies how the body's systems respond to physical activity, both in the moment (an acute response, such as a racing heart during a sprint) and over weeks and months of regular training (a chronic adaptation, such as a lower resting heart rate in a trained athlete).

Homeostasis: the idea behind every physiological response …