Autonomic Nervous System flashcards

Flashcards covering the distinctions, pathways, divisions, neurotransmitters, and responses of the Autonomic Nervous System based on lecture notes.

How does the motor pathway of the Somatic Nervous System differ from that of the Autonomic Nervous System?

The Somatic Nervous System uses one motor neuron from the CNS to the effector, while the Autonomic Nervous System uses two motor neurons (preganglionic and postganglionic).

Describe the two-neuron motor pathway of the Autonomic Nervous System from the CNS to the effector.

The first neuron, with its cell body in the CNS, synapses with the second neuron's cell body in an autonomic ganglion (outside the CNS); this second neuron then goes to the effector.

What are the two major divisions of the Autonomic Nervous System and their primary motor messages?

The Parasympathetic Nervous System (PSNS) manages "rest-or-digest" messages, and the Sympathetic Nervous System (SNS) manages "fight-or-flight" messages.

From which region of the CNS do the first neurons of the Parasympathetic Nervous System originate?

The Parasympathetic Nervous System first neurons originate from the "Cranio-sacral" region of the CNS (cranial nerves III, VII, IX, X and sacral cord S2-S4).

From which region of the CNS do the first neurons of the Sympathetic Nervous System originate?

The Sympathetic Nervous System first neurons originate from the "Thoracolumbar" region of the CNS (T1-L2).

Where is the cell body of a pre-ganglionic neuron located, and what is a key characteristic of its axon?

The cell body is in the CNS, and its axon is usually myelinated, exiting through the white ramus of a spinal nerve to an autonomic ganglion.

Where is the cell body of a post-ganglionic neuron located, and what is a key characteristic of its axon?

The cell body is in an autonomic ganglion, and its axon is typically not myelinated, exiting through the gray ramus to the effector.

What neurotransmitter is released by all pre-ganglionic neurons in both the Sympathetic and Parasympathetic Nervous Systems?

Acetylcholine (ACh).

What neurotransmitter is typically released by post-ganglionic neurons in the Sympathetic Nervous System?

Norepinephrine/noradrenaline (making them adrenergic).

What neurotransmitter is released by post-ganglionic neurons in the Parasympathetic Nervous System?

Acetylcholine (ACh) (making them cholinergic).

Name at least three typical responses associated with the "fight-or-flight" (adrenergic) dominance of the Sympathetic Nervous System.

Examples include dilation of pupils, increased heart rate and blood pressure, increased blood flow to skeletal/cardiac muscle, airways dilate, and increased blood glucose levels.

Name at least three typical "rest-and-digest" (cholinergic) responses of the Parasympathetic Nervous System.

Examples include increased salivation, lacrimation, urination, digestion, and defecation (SLUDD), decreased heart rate, and constriction of pupils.