Neurology, MBBS Second Year. This chapter is split into 3 topics and has
113 practice questions. The topics covered are listed below, followed by
10 free sample questions from the chapter.
Topics in this chapter
Divisions of the nervous system & somatic vs autonomic organisation46 questions
Sympathetic outflow pathway: rami communicans and ganglion routes24 questions
Sample questions: NN 37. AUTONOMIC NERVOUS SYSTEM
10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.
Q1. Which pairing of feature with somatic or autonomic nervous system is correct?
A. Both systems use two neurons to reach the target
B. Somatic — two neurons with a ganglion; autonomic — one neuron
C. Somatic — one neuron, voluntary, ACh on nicotinic receptors; autonomic — two neurons, involuntary, ganglion in between(correct answer)
D. The autonomic system is under voluntary control
Answer: C.The somatic system uses a single motor neuron (voluntary, ACh acting on nicotinic receptors of skeletal muscle), whereas the autonomic system uses two neurons in series with a ganglion interposed (involuntary).
Q2. Assertion: The autonomic nervous system is involuntary. Reason: Its two-neuron arrangement ends on visceral effector organs such as smooth muscle, cardiac muscle and glands.
A. Both Assertion and Reason are true, and the Reason correctly explains the Assertion(correct answer)
B. Both are true, but the Reason does not explain the Assertion
C. Assertion is false but Reason is true
D. Assertion is true but Reason is false
Answer: A.The autonomic nervous system is under involuntary control, with a pre-ganglionic neuron from the brainstem/spinal cord synapsing in a ganglion and a post-ganglionic neuron running to the visceral effector organ.
Q3. What is a pre-ganglionic fibre?
A. A sensory fibre from the viscera
B. A somatic motor fibre to skeletal muscle
C. The neuron that runs from the ganglion to the effector organ
D. The neuron whose cell body lies in the CNS and whose axon ends by synapsing in an autonomic ganglion(correct answer)
Answer: D.The pre-ganglionic fibre/neuron originates in the brainstem or spinal cord and targets (synapses with) the ganglion; the post-ganglionic fibre then runs from the ganglion to the effector organ.
Q4. Which statement correctly contrasts the somatic and autonomic motor pathways?
A. Somatic: two neurons via a ganglion; Autonomic: one neuron from the anterior horn
B. Somatic: uses norepinephrine; Autonomic: uses only acetylcholine
C. Somatic: anterior horn of spinal cord → skeletal muscle, one neuron, ACh on nicotinic receptors; Autonomic: CNS/brainstem → ganglion → effector organ, two neurons(correct answer)
D. Somatic: involuntary; Autonomic: voluntary
Answer: C.The somatic pathway is a single neuron from the anterior horn of the spinal cord to skeletal muscle using acetylcholine on nicotinic receptors, whereas the autonomic pathway uses two neurons in series with a ganglion interposed between the CNS and the effector organ.
Q5. Which sequence shows the hierarchy of the peripheral nervous system correctly?
A. PNS → sensory system and motor system → motor splits into somatic (voluntary) and autonomic (involuntary) → autonomic splits into sympathetic, parasympathetic and enteric(correct answer)
B. PNS → motor → sensory → enteric
C. PNS → sympathetic → parasympathetic → somatic
D. PNS → autonomic → somatic → sensory
Answer: A.The peripheral nervous system divides into sensory and motor systems; the motor system divides into the voluntary somatic nervous system and the involuntary autonomic nervous system, and the autonomic system has three branches — sympathetic, parasympathetic and enteric.
Q6. Which statement about the parasympathetic pre- and post-ganglionic neurons is TRUE?
A. Both neurons are adrenergic
B. The pre-ganglionic neurons are adrenergic and the post-ganglionic cholinergic
C. Short pre-ganglionic neurons and long adrenergic post-ganglionic neurons
D. Long pre-ganglionic cholinergic neurons, terminal (intramural) ganglia, and short post-ganglionic neurons(correct answer)
Answer: D.In the parasympathetic nervous system the pre-ganglionic neurons are long and cholinergic, travelling until they reach the target organ where they synapse in terminal (intramural) ganglia, and the post-ganglionic neurons are short.
Q7. Which summary of autonomic neurotransmitters is correct?
A. Sympathetic: short pre-ganglionic cholinergic, long post-ganglionic adrenergic; Parasympathetic: long pre-ganglionic cholinergic, short post-ganglionic cholinergic(correct answer)
B. Parasympathetic: long pre-ganglionic adrenergic, short post-ganglionic adrenergic
C. Sympathetic: short pre-ganglionic adrenergic, long post-ganglionic cholinergic
D. Sympathetic: both neurons cholinergic; Parasympathetic: both neurons adrenergic
Answer: A.Sympathetic: short pre-ganglionic cholinergic neurons and long post-ganglionic adrenergic neurons. Parasympathetic: long pre-ganglionic cholinergic neurons and short post-ganglionic cholinergic neurons.
Q8. Which structure is an exception to the rule that sympathetic pathways synapse in a ganglion?
A. The arrector pili muscle — its fibres lack any synapse
B. The adrenal gland — its nerve fibres project directly onto the medullary cells without synapsing, and those cells release epinephrine into the bloodstream(correct answer)
C. The sweat gland — its fibres synapse in the dorsal root ganglion
D. The heart — it receives no post-ganglionic fibres
Answer: B.The adrenal glands are an exception: sympathetic nerves project directly onto the medullary cells without synapsing, and the cells themselves act as post-ganglionic neurons, releasing epinephrine (adrenaline) directly into the bloodstream for a widespread sympathetic response.
Q9. Which description applies to the prevertebral (preaortic) ganglion?
A. It forms a chain flanking the vertebral column
B. It lies within the wall of the target organ
C. It is the dorsal root ganglion of sensory fibres
D. It lies in front of the vertebral column near the aorta, and its ganglia synapse with the splanchnic nerves that innervate the abdominal and pelvic viscera(correct answer)
Answer: D.The prevertebral ganglion is named for its location in front of the vertebral column and near the aorta; these ganglia synapse with the splanchnic nerves that innervate the abdominal and pelvic viscera.
Q10. A drug blocks transmission at all autonomic ganglia but spares skeletal muscle. Which feature of autonomic organisation makes this possible?
A. Autonomic fibres use only norepinephrine as their transmitter
B. Somatic fibres use the same ganglion as the autonomic fibres
C. Autonomic fibres have no synapses between the CNS and the effector
D. The ganglion synapse is a separate step that somatic pathways lack(correct answer)
Answer: D.The autonomic system has an extra synapse in a ganglion, which can be blocked without affecting the single-neuron somatic pathway. Standard knowledge (beyond the note): ganglionic blockers.