Full Definition of VARIATION. 1. a: the act or process of varying: the state or fact of being varied b: an instance of varying c: the extent to which or the range in which a thing varies. 2.: declination 6. a change in the form, position, condition, or amount of something. : something that is similar to something else but different in some way. music: a repeated version of a short piece of music with changes in its rhythm, tune, or harmony.
Types of human physiology. Human physiology is the study of functions of the human body that can be divided into the following types:. Cell physiology. This is the cornerstone of human physiology; it is the study of the functions of cells. Special physiology. This is the study of the functions of special organs.
In mammals, major cell types include skin cells, muscle cells, neurons, blood cells, fibroblasts, stem cells, and others. Cell types differ both in appearance and function, yet are genetically identical. Cells are able to be of the same genotype but of different cell type due to the differential expression of the genes they contain.