Bio 205 NOTES 3.12.2018Introduction to the Nervous System1.Divided into: a.Central nervous system: brain and spinal cord (CNS)b.Peripheral nervous system: cranial and spinal nerves (PNS) Tissue1.Tissue is composed of two types of cellsa.Neuronsthat conduct impulses but generally cannot divideb.GlialCells(neuroglia) that support the neurons and cannot conduct impulses butcan divide. Neurons1.Structural and Functional units of the nervous system. 2.General Functionsa.Respond to chemical and physical stimuli b.Conduct electrochemical impulsesc.Release chemical regulatorsd.Enable perception of sensory stimuli, learning, memory, and control of muscles and glands. 3.Most cannot divide, but can repair. Structure of the Neuron and other Cells 1.Neuron Structurea.Dendritesand cell bodyb.Axon, myelin sheath, and Schwann cellsc.Multipolar, bipolar, anaxonic neurons.2.Sensory Neurons, efferent neurons, and interneurons.