PSL201Y1 Chapter Notes -Sodium-Potassium Alloy, Electrochemical Gradient, Active Transport
Document Summary
Central nervous system (cns): consists of the brain and spinal cord. Receives and processes information from sensory organs and the viscera to determine the state of the external environment (sensory information) and internal environment (visceral information). Peripheral nervous system (pns): neurons that provide communication between the central nervous system and organs throughout the body: afferent: neurons transmit sensory and visceral information from the organs to the cns. Neurons are the functional unit of the tissue. They are the excitable cells that communicate by transmitting electrical impulses. Excitable cells: cells capable of producing large rapid electrical signals called action potentials. Glial cells constitute 90% of the cells in the nervous system and provide structural and metabolic support. Most neurons contain three main components: a cell body and two types of neural processes that extend from the cell body the dendrite(s) and an axon.