sympathetic and parasympathetic divisions

13.2

what are the 2 categories of ANS?

sympathetic and parasympathetic divisions

what are the 3 neurons involved in ANS?

visceral motor neuron (VMN), pre-ganglionic, (post) ganglionic

where is the visceral motor neuron (VMN)?

from hypothalamus to brain stem/spinal cord

where is the pre-ganglionic neuron?

from brain stem/spinal cord to autonomic ganglia

where is the ganglionic neuron?

from ganglia to effector

what is the main difference between sympathetic and parasympathetic?

location of the ganglia

where is the ganglion in sympathetic pathways?

close to CNS, far away from effector

what kind of axon do pre-ganglionic neurons have in sympathetic pathways?

short

what kind of axon do ganglionic neurons have in sympathetic pathways?

long

where is the ganglion in parasympathetic pathways?

far away from CNS, close to effector

what kind of axon do pre-ganglionic neurons have in parasympathetic pathways?

long

what kind of axon do ganglionic neurons have in parasympathetic pathways?

short

what is the difference in innervation between sympathetic and parasympathetic pathways?

pre-ganglionic neuron exits the spinal cord at different locations

where do pre-ganglionic neurons exit the spinal cord during sympathetic pathways?

T1-L2

where do pre-ganglionic neurons exit the spinal cord during parasympathetic pathways?

brainstem (cranial nerves) - sacral region (S2-S4)

in sympathetic division, what does pre-ganglionic neuron release when it makes a synapse with the ganglionic neuron?

acetylcholine (ACh)

in sympathetic division, what is released when the ganglionic neuron becomes active?

norepinephrine (directly onto target) or epinephrine (into blood)

what is epinephrine also known as?

adrenaline

in parasympathetic division, what do pre-ganglionic neurons release?

acetylcholine (ACh) (from pre-ganglionic neuron to ganglionic neuron)

in parasympathetic pathways, what do ganglionic neurons release?

more acetylcholine (to activate individual targets)

what is not involved in parasympathetic division?

blood (no neurotransmitters are released into bloodstream)