Peripheral Nervous System: Autonomic and Sensory-Somatic Pathways

All flashcards

What does the PNS do?

The peripheral nervous system carries signals between the central nervous system and the rest of the body, including sensory information traveling toward the CNS and commands traveling outward.

What is a ganglion in an autonomic pathway?

A ganglion is a cluster of neuron cell bodies outside the CNS where a preganglionic neuron synapses with a postganglionic neuron.

What is the sympathetic nervous system's general function?

It coordinates the “fight or flight” response, preparing the body for danger or intense demand by, for example, increasing heart rate and inhibiting digestion.

How does the parasympathetic nervous system support recovery?

It supports “rest and digest” activity, including slowing heart rate, lowering blood pressure, and stimulating digestion after stress.

Which neurotransmitters are commonly released along autonomic pathways?

Both divisions use acetylcholine at the preganglionic synapse. Sympathetic postganglionic neurons generally release norepinephrine, while most parasympathetic postganglionic neurons release acetylcholine.

Quiz questions

1. Which sequence describes a typical autonomic pathway from the CNS to an organ?Answer: Preganglionic neuron → postganglionic neuron → target organ
2. Which neurotransmitter do autonomic preganglionic neurons release at the ganglion?Answer: Acetylcholine
3. Where are parasympathetic preganglionic neuron cell bodies located?Answer: In the brainstem and sacral spinal cord
4. How many pairs of cranial nerves do humans have?Answer: 12 pairs
5. Which spinal root carries sensory information into the spinal cord?Answer: The dorsal root