ABSTRACT
This chapter reviews the key physical forces and their origin. It addresses the issue of force production by living organisms, which requires energy generation and energy transduction into all the cells of the body transported by a complex network of blood vessels and coordinated by the central nervous system. Calcium movement may further promote charged amino acids contained in protein neurotransmitters to be released into neuronal synaptic clefts, for example. Various biochemical reactions within the body are responsible for storing, releasing, absorbing, and transferring the energy humans need to move, breathe, pump blood, process nutrients, excrete waste products, etc. Food energy is the energy stored by chemical bonds and has traditionally been measured in food calories but in physics, different energy units, namely joules, are used as a measure of energy. Animal and human posture and motion are controlled by mechanical tension and compression forces generated by muscles.
