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 substance 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) Potassium (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 postsynaptic neuron Rationale: Neurotransmitters bind to receptors on the post-synaptic neuron to either stimulate or inhibit the generation 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+)