Autonomic Nervous System Quiz: 15 Questions With Answers
Updated
The sympathetic division drives fight-or-flight via norepinephrine and adrenergic receptors; the parasympathetic division drives rest-and-digest via acetylcholine and muscarinic receptors. The vagus nerve provides most parasympathetic outflow to organs, slowing the heart.
This 15-question quiz tests your understanding of the autonomic nervous system, covering the sympathetic and parasympathetic divisions, the neurotransmitters and receptors they use, the fight-or-flight response, and the role of the vagus nerve. It is designed for students reviewing basic neuroscience or physiology and includes explained answers for every question.
Before starting, remember that the autonomic nervous system has two opposing branches: sympathetic, which mobilizes energy for emergencies, and parasympathetic, which conserves energy and maintains routine functions. Most organs receive dual innervation, and the balance between these branches determines physiological state.
The questions
Which division of the autonomic nervous system is primarily active during a 'fight or flight' response?
Which division is often described as 'rest and digest'?
Preganglionic neurons of the sympathetic division exit the spinal cord at which levels?
Parasympathetic preganglionic neurons are located in which regions?
What neurotransmitter is released by all preganglionic neurons in both sympathetic and parasympathetic divisions?
Which receptor type is found on the cell bodies of all autonomic postganglionic neurons?
Most sympathetic postganglionic neurons release which neurotransmitter onto target organs?
Parasympathetic postganglionic neurons release which neurotransmitter at their target organs?
Which type of acetylcholine receptor is found on parasympathetic target organs such as the heart and smooth muscle?
Which brain region is the main integrating center for autonomic responses such as temperature regulation and hunger?
Sympathetic stimulation of the heart causes which effect?
Which cranial nerve carries the majority of parasympathetic outflow to the heart, lungs, and digestive tract?
Stimulation of the vagus nerve on the sinoatrial node of the heart results in what?
How do sympathetic preganglionic fibers influence the adrenal medulla?
Which response is characteristic of parasympathetic activation?
0 of 15 answered · 0 correct
Cheat sheet: key terms
| Sympathetic division | Mobilizes the body for fight or flight; increases heart rate, dilates pupils, and redirects blood to muscles. |
|---|---|
| Parasympathetic division | Promotes rest and digest; slows heart rate, stimulates digestion, and constricts pupils. |
| Acetylcholine | Neurotransmitter released by all preganglionic neurons and by parasympathetic postganglionic neurons. |
| Norepinephrine | Main neurotransmitter released by most sympathetic postganglionic neurons onto target organs. |
| Nicotinic receptors | Ligand-gated ion channels on all autonomic postganglionic neurons, activated by acetylcholine. |
| Muscarinic receptors | G-protein coupled receptors on parasympathetic target organs, activated by acetylcholine. |
| Vagus nerve (CN X) | Provides parasympathetic innervation to the heart, lungs, and most of the digestive tract. |
| Adrenal medulla | Modified sympathetic ganglion; preganglionic fibers directly stimulate chromaffin cells to release epinephrine and norepinephrine. |
Answers explained
Show all 15 answers
- Which division of the autonomic nervous system is primarily active during a 'fight or flight' response? Sympathetic. The sympathetic division prepares the body for emergency, increasing heart rate and redirecting blood flow to muscles.
- Which division is often described as 'rest and digest'? Parasympathetic. Parasympathetic activity conserves energy, slows the heart, and stimulates digestion.
- Preganglionic neurons of the sympathetic division exit the spinal cord at which levels? Thoracolumbar (T1-L2). Sympathetic preganglionic neurons are found in the intermediolateral cell column from T1 to L2, hence the term thoracolumbar.
- Parasympathetic preganglionic neurons are located in which regions? Brainstem and sacral spinal cord (S2-S4). The parasympathetic division has craniosacral outflow: cranial nerve nuclei in the brainstem and sacral spinal segments S2-S4.
- What neurotransmitter is released by all preganglionic neurons in both sympathetic and parasympathetic divisions? Acetylcholine. Both divisions use acetylcholine at the first synapse onto postganglionic neurons.
- Which receptor type is found on the cell bodies of all autonomic postganglionic neurons? Nicotinic. Nicotinic acetylcholine receptors mediate fast excitatory transmission at autonomic ganglia in both divisions.
- Most sympathetic postganglionic neurons release which neurotransmitter onto target organs? Norepinephrine. Sympathetic postganglionic fibers are primarily noradrenergic, except those innervating sweat glands (which release acetylcholine).
- Parasympathetic postganglionic neurons release which neurotransmitter at their target organs? Acetylcholine. All parasympathetic postganglionic fibers are cholinergic, releasing acetylcholine.
- Which type of acetylcholine receptor is found on parasympathetic target organs such as the heart and smooth muscle? Muscarinic. Muscarinic receptors are G-protein coupled and mediate parasympathetic effects like slowed heart rate and increased gland secretion.
- Which brain region is the main integrating center for autonomic responses such as temperature regulation and hunger? Hypothalamus. The hypothalamus coordinates autonomic, endocrine, and behavioral responses to maintain homeostasis.
- Sympathetic stimulation of the heart causes which effect? Increased heart rate and contractility. Norepinephrine activates beta-1 adrenergic receptors on cardiac pacemaker and muscle cells, increasing rate and force.
- Which cranial nerve carries the majority of parasympathetic outflow to the heart, lungs, and digestive tract? Vagus (X). The vagus nerve provides parasympathetic innervation to most thoracic and abdominal viscera.
- Stimulation of the vagus nerve on the sinoatrial node of the heart results in what? Decreased heart rate. Vagal release of acetylcholine on muscarinic receptors hyperpolarizes pacemaker cells, slowing the heart.
- How do sympathetic preganglionic fibers influence the adrenal medulla? They directly stimulate chromaffin cells to release epinephrine and norepinephrine. The adrenal medulla is a modified sympathetic ganglion; preganglionic fibers release acetylcholine onto chromaffin cells, which secrete catecholamines into the blood.
- Which response is characteristic of parasympathetic activation? Pupil constriction and salivation. Parasympathetic activity causes pupil constriction (miosis), increased salivation, and other 'rest and digest' effects.
See it in 3D: open the interactive brain and click any region, or ask the AI coach anything you missed.