The Nervous System

Dr Usama ALAlami

Learning Outcomes

•To describe the major components of the Central, Peripheral and Autonomic Nervous systems.

•To understand the functions of these components.

•To explain how a nervous impulse is transmitted.

•To explain the underlying physiology behind the lesions/damage that occurs in the nervous system.

Functions of the nervous system

•The nervous system is responsible for:

-sensory perception

-cognitive functions

-motor functions

-regulatory functions

Functions of the nervous system

•Collectively, these diverse activities can be grouped into three basic functions:

-sensory input

-integration of information

-motor output

Organisation of the Nervous System

•Central nervous system (CNS), brain and spinal cord

•Peripheral nervous system (PNS), all nervous tissue outside the CNS

Cells of the nervous system

•Neuron. Principal cell of the nervous system - electrically excitable

•Typically, neuronal structure includes:

cell body dendrites axon

synaptic terminals myelin sheath

Axons and Dendrites

Axons

•Each neurone has a single axon

•Branches along axon = axon collaterals

•Conduct impulses away from cell body

Dendrites

•Usually many - Highly branched

•Receives impulses and conduct impulses towards cell body

www.smc.edu