Structure of a neuron MCQs With Answer

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Structure of a neuron MCQs With Answer offers B. Pharm students a focused review of neuronal anatomy, physiology, and pharmacological relevance. This concise, keyword-rich introduction covers major components—dendrites, soma, axon hillock, axon, myelin sheath, nodes of Ranvier, synapse—and links structure to function, signaling, ion channels, neurotransmitter release, and axonal transport. Ideal for exam prep and revision, these questions emphasize clinically relevant concepts such as resting membrane potential, saltatory conduction, demyelinating disorders, and drug targets on ion channels and synaptic proteins. Clear explanations reinforce learning and help build application-based understanding for pharmacy practice. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which neuronal region integrates incoming signals and typically contains Nissl bodies?

  • Axon hillock
  • Dendrite
  • Cell body (soma)
  • Axon terminal

Correct Answer: Cell body (soma)

Q2. Which structure is primarily responsible for initiating action potentials?

  • Axon terminal
  • Axon hillock
  • Dendritic spine
  • Myelin sheath

Correct Answer: Axon hillock

Q3. What is the main function of dendrites?

  • Propagate action potentials over long distances
  • Receive and integrate synaptic inputs
  • Release neurotransmitters into the synaptic cleft
  • Produce myelin

Correct Answer: Receive and integrate synaptic inputs

Q4. Which organelle in neurons is most involved in protein synthesis for membrane and secreted proteins?

  • Mitochondrion
  • Rough endoplasmic reticulum (Nissl substance)
  • Golgi apparatus
  • Smooth endoplasmic reticulum

Correct Answer: Rough endoplasmic reticulum (Nissl substance)

Q5. Saltatory conduction occurs because action potentials jump between which structures?

  • Schwann cells
  • Axon hillocks
  • Nodes of Ranvier
  • Synaptic vesicles

Correct Answer: Nodes of Ranvier

Q6. Which cell type myelinates CNS axons?

  • Schwann cell
  • Satellite cell
  • Oligodendrocyte
  • Astrocyte

Correct Answer: Oligodendrocyte

Q7. Which statement best describes the axon terminal?

  • Site of protein synthesis and Nissl bodies
  • Contains voltage-gated sodium channels to initiate AP
  • Specialized for neurotransmitter release into the synaptic cleft
  • Main metabolic center of the neuron

Correct Answer: Specialized for neurotransmitter release into the synaptic cleft

Q8. Which ion is primarily responsible for depolarization during the rising phase of an action potential?

  • Potassium (K+)
  • Sodium (Na+)
  • Calcium (Ca2+)
  • Chloride (Cl-)

Correct Answer: Sodium (Na+)

Q9. What is the typical approximate resting membrane potential of a neuron?

  • +40 mV
  • 0 mV
  • -70 mV
  • +70 mV

Correct Answer: -70 mV

Q10. Which structure connects the neuronal cell body to the axon and lacks Nissl substance?

  • Dendritic shaft
  • Axon hillock
  • Axon collateral
  • Synaptic cleft

Correct Answer: Axon hillock

Q11. Which transport mechanism moves neurotransmitter-containing vesicles from the soma to the axon terminal?

  • Retrograde axonal transport
  • Anterograde axonal transport
  • Diffusion through cytosol
  • Endocytosis

Correct Answer: Anterograde axonal transport

Q12. Which protein family powers fast axonal transport along microtubules toward the plus end?

  • Dyneins
  • Myosins
  • Kinesins
  • Tubulins

Correct Answer: Kinesins

Q13. In chemical synapses, which ion influx into the presynaptic terminal triggers neurotransmitter release?

  • Sodium (Na+)
  • Potassium (K+)
  • Calcium (Ca2+)
  • Chloride (Cl-)

Correct Answer: Calcium (Ca2+)

Q14. What separates the presynaptic and postsynaptic membranes?

  • Myelin sheath
  • Axoplasm
  • Synaptic cleft
  • Glial limiting membrane

Correct Answer: Synaptic cleft

Q15. Which neuronal classification is based on the number of processes extending from the cell body and includes motor neurons?

  • Bipolar
  • Unipolar
  • Multipolar
  • Pseudounipolar

Correct Answer: Multipolar

Q16. Nissl bodies observed in neuronal cytoplasm are primarily composed of which structures?

  • Mitochondria
  • Ribosomes on rough ER
  • Golgi vesicles
  • Microtubules

Correct Answer: Ribosomes on rough ER

Q17. Which glial cell regulates neurotransmitter uptake, ion homeostasis, and forms part of the blood–brain barrier?

  • Oligodendrocyte
  • Microglia
  • Astrocyte
  • Schwann cell

Correct Answer: Astrocyte

Q18. Which feature increases the speed of action potential conduction in axons?

  • Smaller diameter
  • Larger diameter and myelination
  • Higher density of dendritic spines
  • Thicker cell body

Correct Answer: Larger diameter and myelination

Q19. What effect does demyelination have on conduction?

  • Increases conduction velocity
  • Has no effect on conduction
  • Decreases conduction velocity and may cause conduction block
  • Converts chemical synapses to electrical synapses

Correct Answer: Decreases conduction velocity and may cause conduction block

Q20. Which junction type allows direct electrical coupling between neurons?

  • Chemical synapse
  • Gap junction (electrical synapse)
  • Neuromuscular junction
  • Desmosome

Correct Answer: Gap junction (electrical synapse)

Q21. Which lipid-rich layer insulates axons and increases membrane resistance?

  • Endoneurium
  • Myelin sheath
  • Basement membrane
  • Axolemma

Correct Answer: Myelin sheath

Q22. Schwann cells are found in which part of the nervous system?

  • Central nervous system (CNS)
  • Peripheral nervous system (PNS)
  • Autonomic ganglia exclusively
  • Blood vessels of the brain

Correct Answer: Peripheral nervous system (PNS)

Q23. Which ion channel opens in response to membrane depolarization and contributes to action potential generation?

  • Ligand-gated chloride channel
  • Voltage-gated sodium channel
  • Calcium pump (ATPase)
  • Leak potassium channel

Correct Answer: Voltage-gated sodium channel

Q24. The safety factor of neuromuscular transmission refers to what?

  • The margin by which endplate potential exceeds threshold
  • The number of synapses on a motor neuron
  • The number of mitochondria in axon terminals
  • The ratio of myelinated to unmyelinated fibers

Correct Answer: The margin by which endplate potential exceeds threshold

Q25. Which cytoskeletal element is most important for maintaining axonal transport tracks?

  • Actin filaments
  • Microtubules
  • Intermediate filaments (neurofilaments)
  • Myosin filaments

Correct Answer: Microtubules

Q26. Which neurotransmitter is commonly excitatory in the CNS and acts at AMPA and NMDA receptors?

  • GABA
  • Glycine
  • Glutamate
  • Acetylcholine

Correct Answer: Glutamate

Q27. Which postsynaptic receptor type is ionotropic and mediates fast synaptic transmission for GABA?

  • GABA-A receptor
  • GABA-B receptor
  • Metabotropic glutamate receptor
  • Nicotinic acetylcholine receptor

Correct Answer: GABA-A receptor

Q28. Which process removes neurotransmitter from the synaptic cleft to terminate signaling?

  • Reuptake by transporters
  • Direct enzymatic synthesis in cleft
  • Axonal depolarization
  • Myelination

Correct Answer: Reuptake by transporters

Q29. Which enzyme breaks down acetylcholine in the synaptic cleft?

  • Monoamine oxidase (MAO)
  • Choline acetyltransferase
  • Acetylcholinesterase
  • Butyrylcholinesterase

Correct Answer: Acetylcholinesterase

Q30. What defines a chemical synapse as excitatory at the postsynaptic membrane?

  • Opening of chloride channels leading to hyperpolarization
  • Opening of ligand-gated cation channels causing depolarization
  • Inhibition of voltage-gated channels
  • Release of neuromodulators only

Correct Answer: Opening of ligand-gated cation channels causing depolarization

Q31. Which structural feature of myelinated axons is the main site for action potential regeneration?

  • Internodal regions
  • Schwann cell nucleus
  • Nodes of Ranvier
  • Axon hillock

Correct Answer: Nodes of Ranvier

Q32. Which receptor type mediates slow synaptic responses via G-proteins?

  • Ionotropic receptors
  • Metabotropic receptors
  • Gap junction channels
  • Voltage-gated ion channels

Correct Answer: Metabotropic receptors

Q33. Which glial cell acts as the resident macrophage of the CNS?

  • Astrocyte
  • Oligodendrocyte
  • Microglia
  • Schwann cell

Correct Answer: Microglia

Q34. Which term describes the region of the axon containing a high density of voltage-gated sodium channels?

  • Axonal collateral
  • Nodal region
  • Axon initial segment/axon hillock
  • Internode

Correct Answer: Axon initial segment/axon hillock

Q35. Which molecular motor mediates retrograde axonal transport carrying endosomes back to the soma?

  • Kinesin
  • Dynein
  • Myosin V
  • Tubulin

Correct Answer: Dynein

Q36. Which ion channel contributes to the resting membrane potential by allowing K+ to leak out?

  • Voltage-gated Na+ channel
  • Ligand-gated Ca2+ channel
  • Leak potassium channel
  • NMDA receptor

Correct Answer: Leak potassium channel

Q37. Which structural change is typical in Wallerian degeneration after axonal injury?

  • Immediate remyelination of distal stump
  • Degeneration of distal axon and myelin breakdown
  • Cell body atrophy without axonal changes
  • Proliferation of oligodendrocytes in PNS

Correct Answer: Degeneration of distal axon and myelin breakdown

Q38. The length constant (lambda) of a neuron indicates what property?

  • Speed of action potential propagation
  • Distance passive voltage spreads before decaying significantly
  • Threshold current to trigger an action potential
  • Number of synaptic vesicles released per AP

Correct Answer: Distance passive voltage spreads before decaying significantly

Q39. Which of the following best describes a chemical synapse’s active zone?

  • Region where axon hillock connects to soma
  • Area in presynaptic terminal where vesicles dock and fuse
  • Postsynaptic receptor cluster only
  • Gap junction plaque between glia

Correct Answer: Area in presynaptic terminal where vesicles dock and fuse

Q40. Which ion is crucial for neurotransmitter release and is targeted by some neurotoxins?

  • Sodium (Na+)
  • Potassium (K+)
  • Calcium (Ca2+)
  • Magnesium (Mg2+)

Correct Answer: Calcium (Ca2+)

Q41. Which structural neuronal change is commonly seen in Alzheimer’s disease?

  • Demyelination of peripheral nerves
  • Accumulation of neurofibrillary tangles and loss of synapses
  • Excessive axonal regeneration
  • Proliferation of Schwann cells in CNS

Correct Answer: Accumulation of neurofibrillary tangles and loss of synapses

Q42. Which term describes the specialized postsynaptic membrane fold at the neuromuscular junction?

  • Active zone
  • Motor end plate
  • Node of Ranvier
  • Axon initial segment

Correct Answer: Motor end plate

Q43. Which factor influences the time constant (tau) of a neuronal membrane?

  • Membrane capacitance and resistance
  • Number of synaptic vesicles only
  • Thickness of myelin exclusively
  • Length of dendrites only

Correct Answer: Membrane capacitance and resistance

Q44. Which substance is stored in synaptic vesicles at excitatory CNS terminals?

  • GABA
  • Glycine
  • Glutamate
  • Myelin basic protein

Correct Answer: Glutamate

Q45. Which receptor type at the neuromuscular junction mediates endplate potentials?

  • Muscarinic acetylcholine receptor
  • Nicotinic acetylcholine receptor
  • GABA-B receptor
  • Adrenergic beta receptor

Correct Answer: Nicotinic acetylcholine receptor

Q46. Which feature distinguishes unipolar (pseudounipolar) neurons in sensory ganglia?

  • Two distinct dendrites and one axon
  • Single process that bifurcates into peripheral and central branches
  • Multiple dendrites with short axon
  • No axon present

Correct Answer: Single process that bifurcates into peripheral and central branches

Q47. Which protein family forms the major structural components of myelin in the CNS?

  • Actins
  • Myosins
  • Myelin basic protein (MBP) and proteolipid protein (PLP)
  • Collagens

Correct Answer: Myelin basic protein (MBP) and proteolipid protein (PLP)

Q48. Which phenomenon explains why a strong stimulus after an action potential may not evoke another immediate AP?

  • Refractory period
  • Spatial summation
  • Saltatory conduction
  • Axonal transport

Correct Answer: Refractory period

Q49. Which synaptic plasticity mechanism underlies long-term potentiation (LTP)?

  • Decrease in postsynaptic receptor density
  • NMDA receptor-mediated calcium entry and AMPA receptor insertion
  • Permanent blockade of voltage-gated channels
  • Inhibition of presynaptic calcium channels only

Correct Answer: NMDA receptor-mediated calcium entry and AMPA receptor insertion

Q50. Which laboratory stain is classically used to visualize neuronal cell bodies and Nissl substance?

  • Luxol fast blue
  • Silver stain for axons only
  • Nissl stain (cresyl violet)
  • Hematoxylin and eosin exclusively

Correct Answer: Nissl stain (cresyl violet)

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