Assignment Task: Action Potentials and Nerve Impulses
Q1. What are the functions of the nervous system? What is special about neurons?
Q2. Scientists divide the nervous system by function in several ways. What is the difference between the central nervous system (CNS) and the peripheral nervous system? Sensory and motor? Somatic and autonomic?
Q3. Support cells of the nervous system are called glial cells or neuroglia. What are the four CNS glial cells and what does each do?
Q4. What is the most important glial cell of the peripheral nervous system? What does it do?
Q5. What are the functions of the various parts of a neuron? Body? Axon? Dendrite? Nissl body? Synapse? Axon hillock? Axon terminal?
Q6. What is the resting potential of a neuron? Is the membrane positive on the inside or negative? Describe how the resting potential is established using the terms sodium-potassium ATPase, active transport, K+ leakage channels, facilitated diffusion, energy and negatively charged proteins.
Q7. What is the sodium-potassium pump? What does it do and when does it do it? Is it an active transport channel? Is it a facilitated diffusion channel?
Q8. Describe the action potential (nerve impulse) of a neuron including what causes an action potential (nerve impulse) to start. A correct answer will include the terms synapse, graded potentials, neurotransmitters, dendrites, resting membrane potential, all-or-nothing, facilitated diffusion, voltage-gated channels and threshold.
Q9. Compare graded potentials and action potentials (nerve impulses). A correct answer will include the terms facilitated diffusion, voltage-gated channels, ligand-gated channels, hyperpolarization and depolarization, axon hillock, dendrite and axon. Is a ligand-gated channel an active transport channel? Is it a facilitated diffusion channel?
Q10. What does myelin do for the nervous system? Where is myelin found in the brain? Where is it in the spinal cord? What does it look like?
Q11. Explain saltatory conduction using the terms action potential (nerve impulse), Schwann cell, oligodendrocyte, myelin, myelin sheath, energy conservation, voltage-gated channels, channel distribution and nodes of Ranvier. In which part of a neuron does saltatory conduction occur?
Q12. Describe reflexes. How do reflexes work? What are the 5 steps of a typical reflex arc? (A monosynaptic reflex arc.)
Q13. Describe depolarization, hyperpolarization and threshold potential. What is the relationship between the arrival of an action potential (nerve impulse) at the axon terminus and exocytosis of neurotransmitters?
Q14. What is an IPSP? What is an EPSP? Which hyperpolarizes the membrane? Which depolarizes the membrane? Which takes the neuro closer to an action potential (nerve impulse)? Which takes it farther from an action potential (nerve impulse)? Where do they occur and why are they important?
Q15. What is summation? What is the difference between temporal summation and spatial summation? What happens when two or more graded potentials arrive at the axon hillock?
Q16. What is the difference between the spinal nerves and cranial nerves?
Q17. How do local anesthetics work? Which protein/channel do they interrupt?
Q18. Define neurotransmitters. How and where do they work? What is the difference between excitatory and inhibitory neurotransmitters? What is the neurotransmitter of the neuromuscular synapse?
Q19. What part of the neuron releases (sends) neurotransmitters? What part receives neurotransmitters? What is the effect of neurotransmitters?
Q20. What is the difference between voltage-gated channels and ligand-gated channels? Where are they located? What opens each type of channel?