Neural control and coordination - neuron structure nerve impulse transmission reflex action - Question Bank

1. What is the consequence of a stimulus that is subthreshold for a neuron?
A) A full action potential is generated.
B) No action potential is generated.
C) The neuron fires multiple action potentials.
D) The resting potential becomes more negative.
2. The propagation of an action potential along an axon is a form of:
A) Chemical signaling
B) Electrical signaling
C) Mechanical signaling
D) Hormonal signaling
3. Which reflex is primarily involved in maintaining balance and posture?
A) Withdrawal reflex
B) Stretch reflex
C) Crossed-extensor reflex
D) Pupillary light reflex
4. When a postsynaptic neuron receives an inhibitory neurotransmitter, it causes:
A) Depolarization
B) Hyperpolarization
C) Repolarization
D) An action potential
5. The process of summation in neurons refers to:
A) The integration of multiple inhibitory postsynaptic potentials
B) The summing of excitatory and inhibitory postsynaptic potentials
C) The accumulation of neurotransmitters in the synapse
D) The rapid firing of action potentials
6. Which statement best describes the role of receptors in a reflex arc?
A) They send signals to motor neurons.
B) They convert stimulus energy into electrical signals.
C) They transmit signals within the CNS.
D) They carry out the response.
7. The 'trigger zone' for generating an action potential in a neuron is the:
A) Axon terminal
B) Dendrite
C) Axon hillock
D) Synaptic cleft
8. Which type of neuron transmits information from the CNS to effectors?
A) Sensory neuron
B) Motor neuron
C) Interneuron
D) Afferent neuron
9. A drug that blocks the reuptake of a neurotransmitter would likely:
A) Decrease the effect of the neurotransmitter
B) Increase the concentration and effect of the neurotransmitter in the synaptic cleft
C) Prevent the release of the neurotransmitter
D) Block the receptors on the postsynaptic membrane
10. What is the primary function of the axon terminal?
A) Receive signals
B) Integrate signals
C) Release neurotransmitters
D) Generate action potentials
11. The refractory period ensures that:
A) Action potentials can travel in both directions along the axon
B) A neuron can fire multiple times rapidly
C) An action potential travels in one direction and prevents summation of impulses
D) The resting potential is always maintained
12. Which of the following is NOT a primary neurotransmitter involved in human neural function?
A) Serotonin
B) Dopamine
C) Endorphin
D) Melatonin
13. The sodium-potassium pump is crucial for maintaining the concentration gradients of ions across the neuron membrane, requiring:
A) ATP
B) ADP
C) Glucose
D) Oxygen
14. Hyperpolarization occurs when:
A) Sodium ions enter the cell
B) Potassium ions leave the cell excessively
C) Sodium-potassium pump is activated
D) The membrane potential returns to resting level
15. The depolarization phase of an action potential reaches a peak of about:
A) -70 mV
B) -55 mV
C) +30 mV
D) 0 mV
16. The resting membrane potential is approximately:
A) +30 mV
B) -70 mV
C) 0 mV
D) +70 mV
17. Which glial cells form the myelin sheath in the Peripheral Nervous System (PNS)?
A) Oligodendrocytes
B) Schwann cells
C) Astrocytes
D) Ependymal cells
18. Which glial cells form the myelin sheath in the Central Nervous System (CNS)?
A) Schwann cells
B) Oligodendrocytes
C) Astrocytes
D) Microglia
19. The process by which neurotransmitters are removed from the synaptic cleft is important for:
A) Continuous stimulation of the postsynaptic neuron
B) Allowing the postsynaptic neuron to repolarize
C) Increasing the speed of transmission
D) Generating a stronger signal
20. Which part of the neuron contains the nucleus and major organelles?
A) Axon
B) Dendrite
C) Cell body (Soma)
D) Axon terminal
21. The role of the interneuron in a polysynaptic reflex arc is to:
A) Generate the initial impulse
B) Transmit the impulse directly to the effector
C) Integrate signals and modulate the motor output
D) Detect the stimulus
22. Withdrawal reflexes, like pulling your hand away from a hot object, are examples of:
A) Monosynaptic reflexes
B) Polysynaptic reflexes
C) Somatic reflexes
D) Autonomic reflexes
23. In the knee-jerk reflex, the sensory neuron directly synapses with the:
A) Interneuron
B) Motor neuron
C) Effector muscle
D) Receptor
24. The knee-jerk reflex (patellar reflex) is an example of a:
A) Polysynaptic reflex
B) Monosynaptic reflex
C) Voluntary response
D) Complex learned behavior
25. A simple reflex arc typically involves how many neurons?
A) Two (sensory and motor)
B) Three (sensory, interneuron, motor)
C) Four
D) Five
26. The effector in a reflex arc is responsible for:
A) Detecting the stimulus
B) Transmitting the signal to the CNS
C) Carrying out the response
D) Processing the information in the CNS
27. The motor neuron transmits the impulse from the CNS to the:
A) Receptor
B) Sensory neuron
C) Effector (muscle or gland)
D) Interneuron
28. An interneuron, also known as a relay neuron, is typically found in the:
A) Peripheral nervous system
B) Sensory pathway
C) Central nervous system
D) Motor pathway
29. The sensory neuron transmits the impulse from the receptor to the:
A) Effector
B) Motor neuron
C) Central nervous system (spinal cord or brainstem)
D) Interneuron
30. Which component of a reflex arc detects the stimulus?
A) Motor neuron
B) Effector
C) Receptor
D) Interneuron
31. The pathway followed by a nerve impulse during a reflex action is called a:
A) Neural circuit
B) Synaptic pathway
C) Reflex arc
D) Action potential chain
32. What is a reflex action?
A) A voluntary movement initiated by the brain
B) An involuntary, rapid, and automatic response to a stimulus
C) A learned behavior based on past experiences
D) A conscious decision-making process
33. The space between the presynaptic terminal and the postsynaptic membrane is called the:
A) Axon hillock
B) Synaptic cleft
C) Node of Ranvier
D) Dendritic spine
34. Which of the following is a common inhibitory neurotransmitter?
A) Glutamate
B) Acetylcholine
C) Dopamine
D) Gamma-aminobutyric acid (GABA)
35. Which of the following is a common excitatory neurotransmitter?
A) Gamma-aminobutyric acid (GABA)
B) Acetylcholine
C) Dopamine
D) Serotonin
36. Neurotransmitters are released from the:
A) Presynaptic terminal
B) Postsynaptic membrane
C) Dendrites
D) Cell body
37. Saltatory conduction, which speeds up nerve impulse transmission, occurs in:
A) Unmyelinated axons
B) Dendrites
C) Myelinated axons
D) Cell bodies
38. The 'all-or-none' principle of nerve impulse transmission means that:
A) A neuron can fire with varying strengths
B) A neuron fires to its maximum capacity or not at all
C) The impulse strength depends on the stimulus duration
D) The impulse travels slower in myelinated axons
39. What happens during repolarization of a neuron?
A) Sodium ions rush into the cell
B) Potassium ions rush out of the cell
C) The membrane potential becomes more positive
D) The cell becomes more permeable to sodium
40. The rapid influx of sodium ions into the neuron causes:
A) Repolarization
B) Hyperpolarization
C) Depolarization
D) Resting potential
41. During the generation of an action potential, which ion channels open first, leading to depolarization?
A) Potassium channels
B) Chloride channels
C) Sodium channels
D) Calcium channels
42. Which ion is primarily responsible for the resting membrane potential of a neuron?
A) Sodium (Na+)
B) Chloride (Cl-)
C) Potassium (K+)
D) Calcium (Ca2+)
43. The transmission of a nerve impulse across a synapse is typically mediated by:
A) Electrical signals only
B) Chemical neurotransmitters
C) Hormones
D) Mechanical pressure
44. What is the junction between two neurons called?
A) Synapse
B) Ganglion
C) Plexus
D) Neuromuscular junction
45. The cell body of a neuron is also called the:
A) Axon
B) Dendrite
C) Soma
D) Synapse
46. Gaps in the myelin sheath along an axon are known as:
A) Nodes of Ranvier
B) Synaptic clefts
C) Dendritic spines
D) Axon terminals
47. What is the insulating layer around the axon of many neurons?
A) Neurolemma
B) Myelin sheath
C) Neurilemma
D) Schwann cell
48. The long projection of a neuron that conducts electrical impulses away from the cell body is called the:
A) Dendron
B) Synapse
C) Axon
D) Soma
49. Which part of a neuron receives signals from other neurons?
A) Axon hillock
B) Myelin sheath
C) Dendrites
D) Axon terminal
50. What is the basic functional unit of the nervous system?
A) Nephron
B) Neuron
C) Axon
D) Dendrite