The Neuron and Neural Firing - AP Psychology

1. Name the chemical messengers that cross synapses.

   Neurotransmitters. Chemical substances that carry signals between neurons across synaptic gaps.

2. Identify the neurotransmitter that enhances alertness and arousal.

   Norepinephrine. Excitatory neurotransmitter that increases attention and stress response.

3. Identify the type of neuron that carries information to the central nervous system.

   Sensory neuron. Afferent neurons that relay information from sensory organs to the brain.

4. What role do Schwann cells play in the peripheral nervous system?

   Produce myelin. Glial cells that create insulating myelin sheaths around peripheral axons.

5. What neurotransmitter is linked to mood regulation and sleep?

   Serotonin. Chemical messenger that affects mood, sleep cycles, and emotional well-being.

6. Which neurotransmitter is known for its role in reward and pleasure?

   Dopamine. Neurotransmitter associated with motivation, pleasure, and reward pathways.

7. Which neurotransmitter is involved in muscle movement?

   Acetylcholine. Primary neurotransmitter at neuromuscular junctions enabling muscle contraction.

8. What effect does an inhibitory neurotransmitter have on the neuron?

   Decreases likelihood of firing an action potential. Makes the postsynaptic neuron less likely to reach threshold and fire.

9. Identify the term for a brief electrical charge that travels down an axon.

   Action potential. A rapid electrical signal that propagates along the axon membrane.

10. What is the term for the neuron's outer boundary?

    Cell membrane. Selectively permeable barrier that controls ion movement in and out of the neuron.

11. What is the basic structural unit of the nervous system?

    Neuron. The fundamental building block that processes and transmits information throughout the nervous system.

12. What is the role of motor neurons?

    Transmit signals from the CNS to muscles. Efferent neurons that carry commands from the brain to muscles and glands.

13. What is the primary component of the myelin sheath?

    Lipids. Fatty substances that provide insulation and increase conduction velocity.

14. Name the enzyme that breaks down acetylcholine in the synaptic cleft.

    Acetylcholinesterase. Enzyme that terminates acetylcholine action by breaking it down.

15. Which structure insulates axons and speeds up neural impulses?

    Myelin sheath. Fatty white substance that wraps around axons to increase transmission speed.

16. Identify the phase when the neuron cannot fire an action potential immediately.

    Refractory period. Brief recovery time when the neuron cannot respond to new stimuli.

17. What is the threshold potential necessary to trigger an action potential?

    -55 mV. The minimum voltage required to initiate an action potential.

18. Which structure contains the neuron's genetic material?

    Nucleus. Control center of the cell that houses DNA and regulates cellular functions.

19. What is the role of the synaptic vesicles?

    Store neurotransmitters. Small sacs that contain and release neurotransmitters into the synapse.

20. Name the neurotransmitter that inhibits neural activity in the brain.

    GABA (gamma-aminobutyric acid). Primary inhibitory neurotransmitter that reduces neural excitation.

21. What is the primary function of neurotransmitter receptors?

    Bind neurotransmitters to initiate a response. Protein structures that receive and respond to specific neurotransmitter molecules.

22. What is the function of the axon in a neuron?

    Transmits electrical impulses away from the cell body. The axon conducts nerve impulses from the soma to the terminal buttons.

23. What is the gap between two neurons called?

    Synapse. The junction between neurons where chemical communication occurs.

24. Which ion channels open during the repolarization phase of an action potential?

    Potassium channels. Channels that open to allow potassium efflux during membrane repolarization.

25. Which ion enters the neuron during depolarization?

    Sodium (Na⁺). Positive ion that rushes into the neuron causing depolarization.

26. Identify the part of the neuron that receives signals from other neurons.

    Dendrites. Branch-like extensions that receive incoming chemical signals from other neurons.

27. What is the function of the terminal buttons in a neuron?

    Release neurotransmitters into the synapse. Axon endings that release neurotransmitters when stimulated by action potentials.

28. Which part of the neuron contains the synaptic vesicles?

    Axon terminal. The end portion of the axon where synaptic vesicles are located.

29. Which structure connects the cell body to the axon?

    Axon hillock. Region where action potentials are generated in the neuron.

30. What process describes a neuron returning to its resting state?

    Repolarization. The process of restoring the neuron's negative electrical charge after firing.

31. Name the type of neuron that connects sensory and motor neurons.

    Interneuron. Neurons within the CNS that process information between sensory and motor neurons.

32. What is the significance of the nodes of Ranvier?

    Facilitate rapid conduction of nerve impulses. Gaps in myelin that allow saltatory conduction for faster signal transmission.

33. What effect does an excitatory neurotransmitter have on the neuron?

    Increases likelihood of firing an action potential. Makes the postsynaptic neuron more likely to reach threshold and fire.

34. What is saltatory conduction?

    Jumping of action potentials between nodes of Ranvier. Rapid conduction method where impulses jump between myelinated axon gaps.

35. Identify the process by which neurons communicate electrically.

    Action potential. Electrical signal that enables rapid communication between neurons.

36. Identify the process by which ions flow to produce a nerve impulse.

    Ion exchange. Movement of charged particles across the membrane creates electrical impulses.

37. What is the resting potential of a neuron typically measured in millivolts?

    -70 mV. The electrical charge of an unstimulated neuron at rest.

38. Identify the process of removing neurotransmitters from the synaptic cleft.

    Reuptake. Process where neurotransmitters are recycled back into the presynaptic neuron.

39. Identify the neurotransmitter associated with pain relief.

    Endorphins. Natural opiates that reduce pain perception and create feelings of well-being.

40. What ion exits the neuron during repolarization?

    Potassium (K⁺). Positive ion that flows out of the neuron to restore resting potential.

41. Which ion channels open during the depolarization phase of an action potential?

    Sodium channels. Voltage-gated channels that allow sodium influx during action potential initiation.

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