masalah 1pilihanWhat happens during depolarization in an axon?Na+ ions leave the axonK+ ions enter the axonNa+ ions enter the axonK+ ions leave the axon
masalah 2pilihanHow is a nerve impulse transmitted across a synapse?MechanicallyElectricallyChemicallyOptically
masalah 3pilihanWhat is the role of the sodium-potassium pump in maintaining resting potential?Pumps 3 Na+ out and 2 K+ inPumps 2 Na+ out and 3 K+ inPumps 3 K+ out and 2 Na+ inPumps 2 K+ out and 3 Na+ in
masalah 4pilihanWhat happens during the depolarization phase of an action potential?K+ channels openNa+ channels closeNa+ channels openAction potential peaks
masalah 5pilihanWhich component of a neuron is responsible for conducting impulses away from the cell body?DendritesAxonCell bodySynaptic knob
masalah 6pilihanWhat is the primary function of the synaptic vesicles in a neuron?Store calcium ionsStore neurotransmitter moleculesTransmit electrical signalsProtect the neuron
masalah 7pilihanWhat is the role of the myelin sheath in nerve impulse conduction?To slow down nerve impulse transmissionTo prevent ion exchange across the axon membraneTo act as an electrical insulator and speed up transmissionTo store neurotransmitters
masalah 8pilihanWhat is the function of neurotransmitters in a synapse?To generate electrical impulsesTo transmit chemical signals across the synaptic cleftTo break down acetylcholineTo bind to intracellular receptors
masalah 9pilihanHow does cocaine affect dopamine synapses in the brain?It increases dopamine reabsorptionIt blocks dopamine receptorsIt prevents the release of dopamineIt blocks reabsorption of dopamine, increasing its levels in the synapse
masalah 10pilihanWhat characterizes the refractory period in neurons?The period when the neuron is hyperactiveThe period when the neuron is more sensitive to stimuliThe period when the neuron is insensitive to new stimuliThe period when the neuron is depolarizing
masalah 11pilihanWhich part of the nervous system is responsible for 'fight or flight' responses?Somatic Nervous SystemParasympathetic Nervous SystemSympathetic Nervous SystemCentral Nervous System
masalah 12pilihanWhat is the resting potential of a neuron?The membrane potential when a neuron is not transmitting an impulseThe membrane potential when a neuron is transmitting an impulseThe potential energy stored in a neuronThe electrical charge of a neuron at peak action potential
masalah 13pilihanDuring which phase of the action potential do voltage-gated sodium channels open?Resting stateDepolarizationRepolarizationHyperpolarization
masalah 14pilihanWhat role does calcium play at the synapse?It depolarizes the postsynaptic membraneIt triggers the release of neurotransmittersIt inhibits the action potentialIt acts as a secondary messenger
masalah 15pilihanDuring resting potential, what is the state inside the axon?More positiveMore negativeNeutralEqual to outside
masalah 16pilihanWhat triggers the opening of voltage-gated sodium channels during depolarization?Low potassium levelsHigh calcium influxPresence of a stimulusRelease of neurotransmitters
masalah 17pilihanIn which phase of action potential do voltage-gated potassium channels open?Resting phaseDepolarizationRising phaseFalling phase
masalah 18pilihanWhat is the primary role of the sodium-potassium pump in neurons?To depolarize the neuronTo maintain resting potential by pumping sodium out and potassium inTo facilitate neurotransmitter releaseTo conduct action potentials
masalah 19pilihanWhat structure is responsible for releasing neurotransmitters into the synaptic cleft?Axon terminalDendriteNode of RanvierMyelin sheath
masalah 20pilihanWhat is the difference in charge across the axon membrane during resting potential?Positive inside, negative outsideNegative inside, positive outsideNeutral inside and outsidePositive inside and outside