Course review
Review each learning objective in this topic, then open its concept explanation or question set.
Learning objective
• Neurons carry electrical impulses in the nervous system • Motor, sensory, and relay neurons differ in axon, dendrite, and cell body arrangement
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Sodium-potassium pumps use ATP to move 3 Na⁺ out and 2 K⁺ in • Ion gradients make the resting axon polarized at about -70 mV
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• A nerve impulse is a propagated action potential along a nerve fibre • Stimulus-triggered sodium influx reverses membrane polarity
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Larger axon diameter lowers resistance and increases impulse speed • Myelin sheaths and nodes of Ranvier enable faster saltatory conduction
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Synapses connect neurons to neurons, muscles, or glands • Chemical synapses transmit one way across a narrow synaptic cleft
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Action potentials open voltage-gated Ca²⁺ channels in presynaptic terminals • Ca²⁺ causes vesicle fusion and neurotransmitter exocytosis into the cleft
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Neurotransmitters diffuse and bind receptors on the postsynaptic membrane • EPSPs depolarize the membrane and make threshold more likely
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Threshold opens voltage-gated Na⁺ channels, causing rapid depolarization • Voltage-gated K⁺ channels then repolarize or briefly hyperpolarize the axon
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Local currents from Na⁺ diffusion depolarize the next axon region • Refractory regions behind the impulse help ensure one-way propagation
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Oscilloscope traces show resting potential, threshold, and action potential phases • Stimulus intensity is encoded by impulse frequency, not action potential size
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Myelin insulates axons and ion exchange occurs mainly at nodes of Ranvier • Saltatory conduction jumps node to node and greatly increases speed
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Exogenous chemicals can mimic, block, or prolong neurotransmitter effects • Neonicotinoids bind insect acetylcholine receptors; cocaine blocks dopamine reuptake
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Inhibitory neurotransmitters open Cl⁻ entry or K⁺ exit channels • Hyperpolarization makes threshold harder to reach
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Postsynaptic neurons integrate EPSPs and IPSPs from many synapses • Temporal and spatial summation determine whether threshold is reached
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Pain uses free nerve endings with TRP ion channels in skin and other tissues • Heat, acid, capsaicin, or tissue damage can trigger impulses perceived as pain
Start with the concept explanation, then practise to create mastery evidence.
Learning objective
• Consciousness emerges from coordinated activity across interacting brain regions • EEG, MRI, and fMRI provide evidence for neural correlates of conscious processing
Start with the concept explanation, then practise to create mastery evidence.