MCQ on Nervous System

🟢 Easy Level (1–20)

1. What is the basic unit of the nervous system?
   A) Cell
   B) Neuron ✅
   C) Tissue
   D) Axon
   Explanation: A neuron is the functional and structural unit of the nervous system.
2. Which part of the brain controls balance and coordination?
   A) Cerebrum
   B) Cerebellum ✅
   C) Medulla
   D) Hypothalamus
   Explanation: The cerebellum regulates voluntary movements and balance.
3. The brain is protected by:
   A) Skull ✅
   B) Spine
   C) Ribs
   D) Skin
   Explanation: The skull (cranium) encases and protects the brain.
4. Which structure connects the brain to the spinal cord?
   A) Cerebellum
   B) Medulla oblongata ✅
   C) Hypothalamus
   D) Pons
   Explanation: The medulla oblongata acts as a relay between brain and spinal cord.
5. Which organ is part of the central nervous system?
   A) Heart
   B) Kidney
   C) Brain ✅
   D) Lung
   Explanation: The brain and spinal cord make up the CNS.
6. What carries messages away from the neuron’s cell body?
   A) Dendrite
   B) Axon ✅
   C) Synapse
   D) Soma
   Explanation: The axon conducts nerve impulses away from the cell body.
7. Which part of the neuron receives signals?
   A) Axon
   B) Synapse
   C) Dendrite ✅
   D) Nucleus
   Explanation: Dendrites receive electrical signals from other neurons.
8. How many pairs of cranial nerves do humans have?
   A) 10
   B) 12 ✅
   C) 14
   D) 24
   Explanation: There are 12 pairs of cranial nerves.
9. The largest part of the human brain is the:
   A) Cerebellum
   B) Medulla
   C) Cerebrum ✅
   D) Thalamus
   Explanation: The cerebrum is involved in higher brain functions.
10. What fluid cushions the brain and spinal cord?
    A) Plasma
    B) Synovial fluid
    C) Lymph
    D) Cerebrospinal fluid (CSF) ✅
    Explanation: CSF protects the brain and spinal cord from trauma.
11. Which of the following is a sensory nerve function?
    A) Motor control
    B) Signal reception ✅
    C) Hormone secretion
    D) Muscle contraction
    Explanation: Sensory nerves carry signals to the brain/spinal cord.
12. What is the function of the spinal cord?
    A) Digest food
    B) Pump blood
    C) Relay messages ✅
    D) Filter blood
    Explanation: It transmits messages between the brain and body.
13. The gap between two neurons is called:
    A) Axon
    B) Synapse ✅
    C) Node
    D) Myelin
    Explanation: Synapses allow communication between neurons.
14. Which nerve connects the eye to the brain?
    A) Optic nerve ✅
    B) Vagus nerve
    C) Auditory nerve
    D) Olfactory nerve
    Explanation: The optic nerve transmits visual signals.
15. The involuntary actions are controlled by the:
    A) Cerebrum
    B) Cerebellum
    C) Medulla oblongata ✅
    D) Corpus callosum
    Explanation: The medulla regulates functions like breathing and heartbeat.
16. The outermost layer of the brain is the:
    A) White matter
    B) Grey matter
    C) Meninges
    D) Cerebral cortex ✅
    Explanation: The cortex is involved in sensory perception and thinking.
17. What is the function of motor neurons?
    A) Receive stimuli
    B) Conduct impulses to muscles ✅
    C) Produce hormones
    D) Process emotions
    Explanation: Motor neurons control muscle activity.
18. Which part of the neuron contains the nucleus?
    A) Dendrite
    B) Axon
    C) Cell body (Soma) ✅
    D) Myelin
    Explanation: The soma holds the nucleus and organelles.
19. Which of the following is part of the peripheral nervous system?
    A) Brain
    B) Spinal cord
    C) Cranial nerves ✅
    D) Thalamus
    Explanation: PNS includes cranial and spinal nerves.
20. Which ion is essential for nerve impulse conduction?
    A) Magnesium
    B) Sodium ✅
    C) Calcium
    D) Iron
    Explanation: Sodium influx helps generate action potentials.

🟡 Moderate Level (21–40)

21. The autonomic nervous system controls:
    A) Skeletal muscles
    B) Voluntary actions
    C) Involuntary actions ✅
    D) Reflexes only
    Explanation: It regulates activities like heart rate and digestion.
22. The sympathetic nervous system prepares the body for:
    A) Sleep
    B) Fight or flight ✅
    C) Digestion
    D) Relaxation
    Explanation: It triggers alert responses in stress situations.
23. Which part of the brain regulates temperature and hunger?
    A) Thalamus
    B) Hypothalamus ✅
    C) Medulla
    D) Pons
    Explanation: Hypothalamus maintains homeostasis.
24. Neurotransmitters are released at the:
    A) Axon hillock
    B) Dendrites
    C) Synaptic terminals ✅
    D) Soma
    Explanation: Neurotransmitters are secreted across synapses.
25. The white matter in the brain contains mainly:
    A) Neuron cell bodies
    B) Unmyelinated fibers
    C) Myelinated axons ✅
    D) Blood vessels
    Explanation: Myelinated axons give white matter its color.
26. Which glial cells form the myelin sheath in the CNS?
    A) Schwann cells
    B) Oligodendrocytes ✅
    C) Astrocytes
    D) Microglia
    Explanation: Oligodendrocytes insulate CNS axons.
27. A reflex action is an example of a:
    A) Voluntary response
    B) Conditioned response
    C) Involuntary, automatic response ✅
    D) Learned response
    Explanation: Reflexes are rapid, involuntary actions.
28. Which lobe of the brain is responsible for vision?
    A) Frontal
    B) Temporal
    C) Parietal
    D) Occipital ✅
    Explanation: The occipital lobe processes visual information.
29. Which of the following is NOT a neurotransmitter?
    A) Acetylcholine
    B) Dopamine
    C) Insulin ✅
    D) Serotonin
    Explanation: Insulin is a hormone, not a neurotransmitter.
30. Which structure separates the two cerebral hemispheres?
    A) Cerebellum
    B) Corpus callosum ✅
    C) Thalamus
    D) Medulla
    Explanation: It connects and communicates between hemispheres.
31. Nodes of Ranvier are found in:
    A) Dendrites
    B) Unmyelinated axons
    C) Myelinated axons ✅
    D) Soma
    Explanation: These are gaps in the myelin sheath.
32. The “rest and digest” system is:
    A) Sympathetic
    B) Parasympathetic ✅
    C) Somatic
    D) Central
    Explanation: The parasympathetic system calms body functions.
33. Which part of the brain acts as a relay station for sensory signals?
    A) Hypothalamus
    B) Thalamus ✅
    C) Cerebellum
    D) Pons
    Explanation: Thalamus forwards sensory information to the cortex.
34. What is the function of Schwann cells?
    A) Secrete CSF
    B) Generate action potential
    C) Form myelin sheath in PNS ✅
    D) Act as immune cells
    Explanation: Schwann cells insulate axons in the peripheral nervous system.
35. Multiple sclerosis is caused by damage to:
    A) Neuron soma
    B) Neurotransmitters
    C) Myelin sheath ✅
    D) Axon terminals
    Explanation: It’s an autoimmune attack on myelin.
36. Which structure produces cerebrospinal fluid?
    A) Medulla
    B) Cerebrum
    C) Choroid plexus ✅
    D) Meninges
    Explanation: Choroid plexus filters blood plasma into CSF.
37. Which brain part controls breathing?
    A) Hypothalamus
    B) Medulla oblongata ✅
    C) Cerebrum
    D) Cerebellum
    Explanation: Medulla regulates vital reflexes including respiration.
38. Which ion enters the axon terminal to trigger neurotransmitter release?
    A) Sodium
    B) Potassium
    C) Calcium ✅
    D) Chloride
    Explanation: Calcium triggers synaptic vesicle fusion.
39. Which disease is associated with dopamine deficiency?
    A) Alzheimer’s
    B) Parkinson’s ✅
    C) Epilepsy
    D) Huntington’s
    Explanation: Parkinson’s is linked to dopamine loss in the brain.
40. The limbic system is involved in:
    A) Reflexes
    B) Emotion and memory ✅
    C) Vision
    D) Balance
    Explanation: It controls emotions and memory processing.

🔴 Hard Level (41–50)

41. Saltatory conduction occurs in:
    A) Unmyelinated neurons
    B) Myelinated neurons ✅
    C) Interneurons
    D) Dendrites
    Explanation: Impulses jump between nodes in myelinated axons.
42. Hyperpolarization makes neurons:
    A) More likely to fire
    B) Less likely to fire ✅
    C) Depolarized
    D) Resting
    Explanation: Hyperpolarization increases membrane negativity, inhibiting firing.
43. Which type of glial cell acts as an immune cell in the CNS?
    A) Astrocyte
    B) Oligodendrocyte
    C) Microglia ✅
    D) Schwann cell
    Explanation: Microglia protect the CNS by engulfing pathogens.
44. The refractory period ensures:
    A) Slower transmission
    B) Reversal of signal
    C) One-way transmission of impulses ✅
    D) Enhanced neurotransmitter release
    Explanation: It prevents backward conduction of action potentials.
45. Neurogenesis in adults is mostly found in:
    A) Cortex
    B) Brainstem
    C) Hippocampus ✅
    D) Thalamus
    Explanation: The hippocampus supports memory and shows limited adult neurogenesis.
46. EPSPs (excitatory postsynaptic potentials) cause:
    A) Depolarization ✅
    B) Hyperpolarization
    C) Inhibition
    D) No change
    Explanation: EPSPs make neurons more likely to fire.
47. Which area controls speech production?
    A) Wernicke’s area
    B) Broca’s area ✅
    C) Occipital lobe
    D) Amygdala
    Explanation: Broca’s area manages motor functions of speech.
48. Resting membrane potential of neurons is about:
    A) 0 mV
    B) +70 mV
    C) -70 mV ✅
    D) -30 mV
    Explanation: It’s maintained by the sodium-potassium pump.
49. Which neurotransmitter is inhibitory in the CNS?
    A) Acetylcholine
    B) Glutamate
    C) GABA ✅
    D) Dopamine
    Explanation: GABA decreases neuronal activity.
50. What is the role of the Na+/K+ pump in neurons?
    A) Create neurotransmitters
    B) Restore resting potential ✅
    C) Transmit signals
    D) Generate myelin
    Explanation: The pump restores ionic balance after action potentials.