BIOD 322 NEUROSCIENCE Neural Function and Transmission Latest Review Exam Q & A 2024 1. What is the primary role of myelin in neural transmission? - A) To increase the speed of action potentials - B) To prevent the action potentials - C) To produce neurotransmitters - D) To insulate the axon hillock Answer: A) To increase the speed of action potentials Rationale: Myelin is a fatty s ubstance that insulates axons, allowing electrical impulses to transmit quickly and efficiently along the nerve cells. 2. Which ion's influx is most directly responsible for the depolarization phase of an action potential? - A) Sodium (Na+) - B) Pot assium (K+) - C) Calcium (Ca2+) - D) Chloride (Cl -) Answer: A) Sodium (Na+) Rationale: During depolarization, sodium channels open, allowing Na+ to flow into the neuron, causing the interior to become more positive. 3. What is the function of neurotransmitters in synaptic transmission? - A) To generate electrical impulses in the post -synaptic neuron - B) To carry electrical impulses across the synaptic cleft - C) To modulate the strength of the signal sent to the post -synaptic neuron - D) To be reabsorbed by the pre -synaptic neuron Answer: C) To modulate the strength of the signal sent to the post -
synaptic neuron Rationale: Neurotransmitters bind to receptors on the post -synaptic neuron to either stimulate or inhibit the gener ation of a new action potential. 4. In a resting neuron, the concentration of which ion is typically higher inside the cell compared to outside? - A) Sodium (Na+) - B) Potassium (K+) - C) Calcium (Ca2+) - D) Chloride (Cl -) Answer: B) Potass ium (K+) Rationale: Potassium ions are more concentrated inside the neuron at rest, contributing to the resting membrane potential. 5. What is the significance of the sodium -potassium pump in maintaining the resting membrane potential? - A) It pumps sodium and potassium ions in equal quantities - B) It pumps sodium ions out and potassium ions in, against their concentration gradients - C) It uses the energy from ATP to transport chloride ions - D) It equalizes the concentration of ions acros s the membrane Answer: B) It pumps sodium ions out and potassium ions in, against their concentration gradients Rationale: The sodium -potassium pump actively transports Na+ out of the cell and K+ into the cell, which is essential for maintaining the resting membrane potential. 6. What is an excitatory neurotransmitter? - A) A neurotransmitter that decreases the likelihood of an action potential in the post -synaptic neuron - B) A neurotransmitter that increases the likelihood of an action potent ial in the post -synaptic neuron - C) A neurotransmitter that has no effect on the post -synaptic neuron - D) A neurotransmitter that is only found in the central nervous system Answer: B) A neurotransmitter that increases the likelihood of an actio n potential in the post -synaptic neuron Rationale: Excitatory neurotransmitters bind to receptors and increase the chance that the post -synaptic neuron will fire an action potential. 7. What is the role of calcium ions at a chemical synapse? - A) They initiate the repolarization phase of an action potential - B) They are pumped out of the neuron by the sodium -potassium pump - C) They trigger the release of neurotransmitters into the synaptic cleft - D) They deactivate neurotransmit ters in the synaptic cleft Answer: C) They trigger the release of neurotransmitters into the synaptic cleft Rationale: Calcium ions enter the pre -synaptic neuron upon an action
synaptic neuron Rationale: Neurotransmitters bind to receptors on the post -synaptic neuron to either stimulate or inhibit the gener ation of a new action potential. 4. In a resting neuron, the concentration of which ion is typically higher inside the cell compared to outside? - A) Sodium (Na+) - B) Potassium (K+) - C) Calcium (Ca2+) - D) Chloride (Cl -) Answer: B) Potass ium (K+) Rationale: Potassium ions are more concentrated inside the neuron at rest, contributing to the resting membrane potential. 5. What is the significance of the sodium -potassium pump in maintaining the resting membrane potential? - A) It pumps sodium and potassium ions in equal quantities - B) It pumps sodium ions out and potassium ions in, against their concentration gradients - C) It uses the energy from ATP to transport chloride ions - D) It equalizes the concentration of ions acros s the membrane Answer: B) It pumps sodium ions out and potassium ions in, against their concentration gradients Rationale: The sodium -potassium pump actively transports Na+ out of the cell and K+ into the cell, which is essential for maintaining the resting membrane potential. 6. What is an excitatory neurotransmitter? - A) A neurotransmitter that decreases the likelihood of an action potential in the post -synaptic neuron - B) A neurotransmitter that increases the likelihood of an action potent ial in the post -synaptic neuron - C) A neurotransmitter that has no effect on the post -synaptic neuron - D) A neurotransmitter that is only found in the central nervous system Answer: B) A neurotransmitter that increases the likelihood of an actio n potential in the post -synaptic neuron Rationale: Excitatory neurotransmitters bind to receptors and increase the chance that the post -synaptic neuron will fire an action potential. 7. What is the role of calcium ions at a chemical synapse? - A) They initiate the repolarization phase of an action potential - B) They are pumped out of the neuron by the sodium -potassium pump - C) They trigger the release of neurotransmitters into the synaptic cleft - D) They deactivate neurotransmit ters in the synaptic cleft Answer: C) They trigger the release of neurotransmitters into the synaptic cleft Rationale: Calcium ions enter the pre -synaptic neuron upon an action
