Sympathetic Nervous System Pathways Quiz

Somatic motor nervous system – a one neuron system, meaning a single neuron runs from the spinal cord or brain stem out to the skeletal muscle and releases a neurotransmitter. Somatic motor signals start in the ______ horn

Autonomic Nervous System – a two neuron system. Autonomic motor signals start in the lateral gray horn. The axons run out of the anterior root and they are ______

The second neuron is unmyelinated and the axon terminals will branch and synapse with the effectors of the autonomic nervous system (cardiac muscle, smooth muscle, and ______)

The first neuron releases the neurotransmitter acetylcholine; it is always ______

The second neuron releases a different neurotransmitter which is determined by the system (sympathetic or ______)

Sympathetic Division: Called the thoracolumbar division because all preganglionic neurons exit the Central Nervous System between T1 and ______

The preganglionic neuron can synapse right here (same level) Other times it will travel up or down the chain and then synapse. Or it can leave the trunk without synapsing and go to the prevertebral ganglia and synapse (this is called a ______ nerve – a collection of myelinated nerve fibers that have left the trunk).

Or it can leave the trunk without synapsing and go to the adrenal medulla and synapse with the chromaffin cells. After the neuron synapses, there are three ways to get to the effectors (all of which contain postganglionic fibers): Peripheral effectors, such as sweat glands, pass back into the spinal nerve via the gray ramus (because the postganglionic neuron is not myelinated) Visceral effectors, such as the heart, go through sympathetic nerves which are post ganglionic fibers going directly from sympathetic chain to visceral organs Cephalic periarterial nerves which are sympathetic nerve fibers surrounding the carotid arteries going to effectors in the head. The ______ nerve contains preganglionic fibers from sympathetic chain to either the adrenal medulla or the prevertebral ganglia.

Called the cranialsacral division because it comes off of four cranial nerves and three sacral nerves CN III (oculomotor), VII (facial), IX (glossophangeal), and X (vagus) and SN S2-S4 Ganglia is called terminal ganglia because they are located on or near the effectors. Cholinergic – having to do with acetylcholine A neuron that releases acetylcholine is called ______.

Adrenergic – having to do with epinephrine and/or norepinephrine (another name for epinephrine is adrenaline) A neuron that releases epinephrine or norepinephrine is called ______.

All preganglionic neurons are ______, meaning they release acetylcholine at their axon terminals.

The postganglionic neuron is going to have receptors for acetylcholine, these receptors are nicotinic receptors (always excitatory) Sympathetic postganglionic neurons are ______ which means they release norepinephrine and the effector tissue has receptors called adrenergic receptors.