Neurophysiology – CNS, PNS, neuron structure, impulse transmission, neurotransmitters, reflexes - Question Bank

1. What is the role of acetylcholine (ACh) in the peripheral nervous system?
A) It is the primary inhibitory neurotransmitter.
B) It excites skeletal muscles at the neuromuscular junction.
C) It regulates mood and emotions.
D) It is involved in the 'fight or flight' response.
2. The phenomenon where a neuron becomes less responsive to repeated stimulation after prolonged exposure to a neurotransmitter is known as:
A) Sensitization
B) Habituation
C) Potentiation
D) Depolarization
3. Damage to the myelin sheath can lead to which of the following conditions?
A) Parkinson's disease
B) Alzheimer's disease
C) Multiple Sclerosis (MS)
D) Epilepsy
4. Which part of the neuron contains the nucleus and major organelles?
A) Axon
B) Dendrite
C) Cell body (soma)
D) Myelin sheath
5. A polysynaptic reflex arc involves:
A) Only a sensory neuron and a motor neuron
B) A sensory neuron, a motor neuron, and at least one interneuron
C) Only interneurons
D) A direct connection from the brain to the effector
6. What is the term for the process where neurotransmitters are taken back into the presynaptic neuron?
A) Degradation
B) Reuptake
C) Diffusion
D) Synthesis
7. Which type of neurotransmitter is Gamma-aminobutyric acid (GABA)?
A) Excitatory
B) Inhibitory
C) Modulatory
D) Excitatory and inhibitory
8. What is the primary role of sensory receptors in the PNS?
A) To transmit commands from the CNS to effectors
B) To detect stimuli from the internal and external environment
C) To process complex information and form memories
D) To regulate heart rate and breathing
9. The brain region responsible for coordinating voluntary movements and balance is the:
A) Cerebrum
B) Cerebellum
C) Brainstem
D) Thalamus
10. Which of the following is a key characteristic of the peripheral nervous system (PNS)?
A) It is entirely responsible for higher cognitive functions.
B) It includes the brain and spinal cord.
C) It connects the CNS to the rest of the body.
D) It is solely responsible for involuntary actions.
11. Which part of the neuron integrates incoming signals?
A) Axon terminal
B) Cell body (soma) and axon hillock
C) Myelin sheath
D) Dendrites only
12. What is summation in neurophysiology?
A) The process of neurotransmitter synthesis
B) The combined effect of multiple synaptic inputs on a neuron's membrane potential
C) The insulation of axons by myelin
D) The rapid firing of a single action potential
13. The 'all-or-none' principle of action potential generation means that:
A) A neuron will fire an action potential only if the stimulus reaches a certain threshold
B) The amplitude of an action potential varies with the strength of the stimulus
C) A neuron can fire multiple action potentials simultaneously
D) The speed of an action potential is constant regardless of axon diameter
14. Which neurotransmitter plays a key role in reward pathways and is implicated in addiction?
A) Serotonin
B) GABA
C) Dopamine
D) Glutamate
15. When a neurotransmitter binds to its receptor on the postsynaptic membrane, it can cause:
A) Depolarization (excitatory postsynaptic potential - EPSP)
B) Hyperpolarization (inhibitory postsynaptic potential - IPSP)
C) Both depolarization and hyperpolarization
D) Immediate cessation of signal transmission
16. In a chemical synapse, neurotransmitters are stored in vesicles within the:
A) Postsynaptic neuron
B) Presynaptic terminal
C) Synaptic cleft
D) Dendrite
17. What type of synapse involves direct electrical connection between neurons?
A) Chemical synapse
B) Electrical synapse
C) Axodendritic synapse
D) Axosomatic synapse
18. The process of impulse transmission along a myelinated axon is called:
A) Continuous conduction
B) Saltatory conduction
C) Synaptic transmission
D) Graded potential
19. Gaps in the myelin sheath where the action potential is regenerated are called:
A) Axon terminals
B) Dendritic spines
C) Synapses
D) Nodes of Ranvier
20. What is the insulating layer around many axons that speeds up nerve impulse transmission?
A) Dendrite
B) Synapse
C) Myelin sheath
D) Node of Ranvier
21. The parasympathetic nervous system is primarily involved in:
A) Stimulating heart rate and digestion
B) Conserving energy and promoting 'rest and digest' functions
C) Initiating rapid muscle contractions
D) Causing pupil dilation
22. Which division of the ANS prepares the body for 'fight or flight' responses?
A) Parasympathetic nervous system
B) Sympathetic nervous system
C) Enteric nervous system
D) Somatic nervous system
23. The autonomic nervous system (ANS) is responsible for:
A) Voluntary control of skeletal muscles
B) Conscious thought and decision-making
C) Regulating involuntary bodily functions
D) Processing sensory input from the environment
24. The PNS is divided into the somatic nervous system and the:
A) Central nervous system
B) Autonomic nervous system
C) Brainstem
D) Cerebral cortex
25. The spinal cord's primary role in the CNS includes:
A) Processing complex cognitive functions
B) Initiating voluntary movements
C) Relaying sensory information and coordinating reflexes
D) Regulating emotions and memory
26. Which of the following is NOT a component of the CNS?
A) Brain
B) Spinal cord
C) Cranial nerves
D) Cerebellum
27. The brain is primarily composed of which part of the nervous system?
A) Peripheral Nervous System (PNS)
B) Central Nervous System (CNS)
C) Autonomic Nervous System (ANS)
D) Somatic Nervous System (SNS)
28. The withdrawal reflex (e.g., pulling your hand away from a hot object) is an example of what type of reflex?
A) Autonomic reflex
B) Somatic reflex
C) Conditioned reflex
D) Complex reflex
29. The structure that carries out the response in a reflex action is called the:
A) Receptor
B) Sensory neuron
C) Motor neuron
D) Effector
30. Which type of neuron carries impulses from the CNS to muscles or glands?
A) Sensory neuron
B) Motor neuron
C) Interneuron
D) Afferent neuron
31. In a simple reflex arc, what is the first component that detects a stimulus?
A) Motor neuron
B) Interneuron
C) Sensory receptor
D) Effector
32. The pathway followed by a nerve impulse during a reflex action is called a:
A) Synaptic pathway
B) Neural circuit
C) Reflex arc
D) Action potential chain
33. What is a reflex action?
A) A voluntary response to a stimulus
B) An involuntary, rapid response to a stimulus
C) A learned behavior involving complex thought processes
D) A conscious decision made by the brain
34. The process of removing neurotransmitters from the synaptic cleft after signal transmission is crucial for:
A) Maintaining continuous excitation
B) Allowing for precise and controlled signaling
C) Increasing the strength of the signal
D) Preventing reuptake by the presynaptic neuron
35. What is the role of inhibitory neurotransmitters?
A) To increase the likelihood of a neuron firing an action potential
B) To decrease the likelihood of a neuron firing an action potential
C) To speed up the transmission of nerve impulses
D) To block the release of excitatory neurotransmitters
36. Which neurotransmitter is often associated with mood, sleep, and appetite regulation?
A) Glutamate
B) GABA
C) Serotonin
D) Epinephrine
37. Which neurotransmitter is primarily associated with muscle contraction at the neuromuscular junction?
A) Serotonin
B) Dopamine
C) Acetylcholine (ACh)
D) Norepinephrine
38. Which of the following is a common excitatory neurotransmitter in the CNS?
A) Gamma-aminobutyric acid (GABA)
B) Acetylcholine (ACh)
C) Glutamate
D) Dopamine
39. What are chemical messengers released by neurons to transmit signals across synapses called?
A) Ions
B) Action potentials
C) Neurotransmitters
D) Receptors
40. What causes repolarization of the neuron membrane after an action potential?
A) Influx of sodium ions
B) Efflux of potassium ions
C) Influx of chloride ions
D) Active transport of sodium ions out of the cell
41. During an action potential, which ion primarily rushes into the neuron?
A) Potassium (K+)
B) Chloride (Cl-)
C) Sodium (Na+)
D) Calcium (Ca2+)
42. What is the resting potential of a neuron?
A) The electrical charge across the membrane when the neuron is inactive
B) The electrical charge across the membrane during an action potential
C) The influx of sodium ions into the neuron
D) The efflux of potassium ions from the neuron
43. The process by which a neuron transmits a signal is called:
A) Synaptic transmission
B) Impulse conduction
C) Action potential generation
D) All of the above
44. What is the electrical signal that travels along a neuron called?
A) Neurotransmitter
B) Action potential
C) Synaptic potential
D) Resting potential
45. The gap between two neurons where information is transmitted is known as the:
A) Axon terminal
B) Dendritic spine
C) Synapse
D) Node of Ranvier
46. What is the long, slender projection of a neuron that conducts electrical impulses away from the cell body?
A) Dendrite
B) Axon
C) Synapse
D) Nerve impulse
47. Which part of a neuron typically receives signals from other neurons?
A) Axon hillock
B) Cell body (soma)
C) Myelin sheath
D) Dendrites
48. What is the main structural and functional unit of the nervous system called?
A) Axon
B) Dendrite
C) Neuron
D) Synapse
49. Which part of the peripheral nervous system (PNS) controls voluntary movements of skeletal muscles?
A) Autonomic nervous system
B) Sympathetic nervous system
C) Somatic nervous system
D) Parasympathetic nervous system
50. What is the primary function of the central nervous system (CNS)?
A) To transmit sensory information from the body to the brain
B) To process information and coordinate bodily activities
C) To control voluntary muscle movements
D) To regulate involuntary bodily functions like heart rate