innervate organs under involuntary control

there are 4 kinds of autonomic nerves

ex) cardiac muscle, smooth m. of organs, glands

1. in the brain or spinal cord

-synapses in the autonomic ganglion

2.  Cell bodies in the ganglion & synapses on the effector

Originate in the midbrain, hindbrain, thoracic, lumbar or sacral spinal cord

(before it reaches the ganglion

originate in the ganglion

-supplies to bodies organs

1. Parsympathetic- rest & digest

-slows heart rate, increase digestive activities

-slows it by the release of ACh

2. sympathetic- fight or flight

-increases heart reat, etc.

neurotransmitter used by all preganglionic neurons  & parasympathetic neurons

-the synapses are called cholinergic

neurotransmitter released by sypathetic neurons

-the synapses are called adrenerigic

1. Stimualation- causes vessel constriction

2. Inhibition- Causes dilation & inhibits contraction of longs and blood vessels

-two types

1. A- a1 & a2

2. B- b1 & b2

A and B use g-proteins and the 2nd messenger system

located in presynaptic axons

-when stimulated result in inhinition of norepinephrine release in synapses

-negative feedback

Nicotinic

in autonomic ganglion

-stimulated by ACh

-serves as ion channels

In visceral organs

-stimulatory or inhibitory

-use g-proteins and second messenger system

-erection of penis

-innervated by parasympathetic

-causes reaxation and vasodilaton by nitric acid

adrenal medulla

arrector pilli m.

sweat glands

most blood vessels

important for body temp.

regulated by increase and decrease in sympathetic n. activity