Peripheral Nervous System Flashcards
What areas does the ANS innervate?
organs and tissues (smooth muscle, cardiac muscle, and glands) within the viscera
Does the autonomic nervous system require control at the conscious level?
Normally no
What does the somatic nervous system innervate?
skeletal muscles in a voluntary manner
ANS is one of the primary effectors of what in the body?
homeostasis- by regulating the organs
what are the three subdivisions of the ANS
sympathetic, parasympathetic, and enteric (gut)
True or false: sympathetic and parasympathetic have antagonistic actions to each other
True
Name the 3 principles of the ANS
- two neurons between CNS and effector organ
- innervates smooth muscle, cardiac muscle, and glands
- either excitatory or inhibitory
What other name is the sympathetic division called?
Thoracolumbar Division
Where does the sympathetic preganglionic neuron cell body originate?
in the intermediolateral gray column of T1-L3
Where do the sympathetic preganglionic fibers exit the spinal cord?
at the level that their cell bodies are located T1-L3
Which neuron is longer in the sympathetic division?
the postganglionic fibers are longer than the preganglionic fibers because they travel a longer distance to their target
Where are the sympathetic preganglionic neurons located for ocular structures?
T1-T3
Where are the parasympathetic preganglionic cells located?
In several of the brainstem nuclei and in S2-S4 (sacral)
What is another name for the parasympathetic division
craniosacral division
Which neurons are longer in the parasympathetic division?
The preganglionic neurons are longer, the postganglionic neurons are close to their targets
Where do the parasympathetic preganglionic axons exit the brainstem?
through cranial nerves 3 (oculomotor), 7 (facial), 9 (glossopharyngeal) and 10 (vagus)
Where do the parasympathetic preganglionic neurons of the oculomotor nerve synapse with the postganglionic parasympathetic neurons?
Ciliary ganglion
What needs to be released in order to send a signal to the next neuron at a synapse?
neurotransmitter
What is the neurotransmitter released by the preganglionic fiber in the sympathetic pathway?
Acetylcholine
What is the neurotransmitter released by the postganglionic fiber in the sympathetic pathway?
Norepinephrine
What is the neurotransmitter released by the preganglionic fiber in the parasympathetic pathway?
Acetylcholine
What is the neurotransmitter released by the postganglionic fiber in the parasympathetic pathway?
Acetylcholine
A fiber that releases acetylcholine is called what
cholinergic
A fiber that releases norepinephrine is called what
adrenergic
What is an agonist?
A drug that mimics the action of a neurotransmiter
What is an antagonist?
A drug that blocks the receptor site for neurotransmitters
