Physiology Exam 1 SG

Structural Characteristics  Physiology = study of how living organisms function o Hierarchy of structural organization  Atoms > molecules > cells > tissues > organs > organ systems > organism o Integrated physiolog ...

Structural Characteristics  Physiology = study of how living organisms function o Hierarchy of structural organization  Atoms > molecules > cells > tissues > organs > organ systems > organism o Integrated physiological function  Understanding how changes in function at each level lead to a whole-body response o Interrelationships between structure & function  Cell division  Multiplication of cells  Only a spherical mass of identical cells without cell differentiation  Cell differentiation  Unspecialized cell > specialized cell  200 distinct kinds of cells in the body  Classified in broad types of function o Muscle cells o Neurons o Epithelial cells o Connective tissue cells  Tissues o Muscle tissue and cells  Function  Mechanical force generation  Types  Skeletal o Voluntary  Cardiac o Involuntary o Found only in the heart  Smooth o Involuntary o Make up walls of tubes in the body (blood vessels, gastrointestinal tract, etc.) o Contraction helps to move substances along  Differ in shape, mechanisms controlling contractile activity, and in location in various organs o Nervous tissue and neurons  Function  Communication via generation of electrical signals o A neuron signal may signal other neurons or it may stimulate a gland cell to secrete substances o Epithelial tissue and cells  Function  Barrier: coverings of internal & external surfaces o Compartmentalization o Structures  Basement membrane: protein layer of which the epithelial cells rest on, anchoring the tissue  Basolateral side: side of cell anchored to basement membrane  Apical (luminal) side: side of cell that faces the interior of a structure  Tight junctions  Selective barriers