Autonomic Nervous System

Objectives

• Briefly describe autonomic nervous system

• Describe main functions of parasympathetic and sympathetic system

Overview

• The autonomic nervous system functions outside of our conscious awareness

• The autonomic nervous system makes routine adjustments in our body’s systems

• The autonomic nervous system:• Regulates body temperature• Coordinates cardiovascular, respiratory, digestive, excretory, and reproductive

functions

Subdivisions of Autonomic Nervous System• The autonomic nervous system consists of two major subdivisions• Sympathetic division• Also called the thoracolumbar division• Known as the “fight or flight” system

• Parasympathetic division• Also called the craniosacral division• Known as the “rest and digest” system

Somatic motor neuron

Major components

• Neuron• Sensory- Afferent• Motor – Efferent

• Neurotransmitter• endogenous chemicals that transmit signals across a synapse

• Effector Effector Organs• specific tissues stimulated by the autonomic specific tissues stimulated by the

autonomic nervous system

Neurotransmitters

• Acetylcholine• Pre -ganglionic Neurotransmitter for both systems• Post -ganglionic neurotransmitter for the parasympathetic nervous system

• Norepinephrine• Post -ganglionic neurotransmitter for the sympathetic Nervous system

Synapse

• Junction of Pre and Post synaptic neurons• Neurotransmitter produced in presynaptic membrane• Moves across synaptic space• binds with receptor on postsynaptic membrane• causes impulse potential

Level of Autonomic Control

Sympathetic nervous system

Sympathetic ganglion

Adrenal Medulla

• This area of the nervous system is also stimulated by the release of norepinephrine.• This releases noradrenalin & adrenalin• These are released into the body to also react with receptors and prolong the

effects of sympathetic stimulation

Sympathetic Stimulation

The Parasympathetic Nervous System

Parasympathetic Stimulation

Thank you