Nervous system I Chapter 10

Nervous system Trillions of nerve cells linked together in a highly organized manner to form the rapid control system of the body Neurons- nerve cells, carry electrical signals rapidly and over long distances

Divisions of the nervous system Central nervous system (CNS) Brain Spinal cord Peripheral nervous system (PNS) Nerves in other parts of the body Spinal and cranial nerves

Brain Spinal cord Cranial nerves

General functions of the nervous system Sensory Gather information Info carried to CNS Integrative Sensory information used to create sensations, memory, thoughts, decisions Motor Decisions acted upon Information carried from CNS to PNS

Two broad types of nerve paths

Cells of the nervous system Neuron Glia

Neurons Vary in size and shape Share certain features Dendrites- receive signal Cell body- contains nucleus Axon- transmits signal to another neuron

Neuron structure Dendrites Cell body Receive incoming signals Transfer to cell body of neuron Cell body Typical cell structures cytoskeleton

Neuron structure Axon Transmits signal to synapse

Neuron structure- synapse Region where axon meets target cell Space across which neurotransmitter diffuses

Myelination of axons Myelin- lipids and proteins that wrap around an axon White matter Contains myelinated neurons Gray matter Contains unmyelinated neurons Dendrite Node of Ranvier Myelinated region of axon Axon Unmyelinated region of axon Neuron cell body nucleus

http://www. youtube. com/watch http://www.youtube.com/watch?v=x4PPZCLnVkA&list=PL3EED4C1D684D3ADF&index=26