8.0 Module Overview

The case this module reads

Her scans are clean and her strength is normal. But two different kinds of numbness sit on the same chart — one sharp-edged and one-sided, one fading and symmetric — and the second one started before the crash that everyone blamed for it.

By the end you can

1. Describe how the nervous systemThe organ system that controls body functions using electrical and chemical signals. is organized — CNSComposed of the brain and spinal cord; integrates and processes information.  and PNS, sensory and motor, somatic and autonomic — and use the terms nerve, tract, nucleusThe control center of the cell that contains DNA and directs cellular activities. and ganglionA cluster of neuron cell bodies located in the peripheral nervous system (PNS). correctly. (Ch 1)
2. Identify the parts of a neuron, classify neurons by structure and by function, and recognize a neuron, a nerve and a ganglion under the microscope. (Ch 1, Ch 2, Ch 6)
3. Describe the neuroglia of the CNS and PNS, explain how Schwann cellsPNS glial cells that form the myelin sheath around peripheral nerve fibers. and oligodendrocytesGlial cells in the CNS that form the myelin sheath around axons. build myelin, and explain why white matterThe outer portion of the spinal cord made of myelinated nerve fibers that transmit signals. is white. (Ch 2, Ch 5)
4. Explain the resting membrane potential: the ion gradients, leak channelsProtein passages in the cell membrane that allow specific molecules to pass through. and the Na⁺/K⁺ pump that hold it. (Ch 3)
5. Compare graded potentials with action potentials, and explain EPSPs, IPSPs and temporal and spatial summationThe addition of multiple signals from different synapses at the same time. at the trigger zone. (Ch 4)
6. Explain thresholdThe minimum voltage needed to trigger an action potential., the phases of the action potential, the all-or-none rule and the refractory periods in terms of ion channels. (Ch 3)
7. Explain continuous and saltatory conductionThe rapid transmission of impulses in myelinated axons by jumping between nodes of Ranvier., what sets conductionThe transmission of nerve impulses along neurons. speed (fiber groups A, B, C), and what demyelination and axon loss each do to a nerve study. (Ch 2, Ch 3, Ch 5)
8. Describe chemical and electrical synapsesSynapses where cells are directly connected by gap junctions; allow rapid signal transmission., the calcium-triggered events of synaptic transmission, the major neurotransmittersChemicals released by neurons to transmit signals across a synapse. and their receptors, how a signal is ended, and the basicA solution with a pH above 7, having a lower concentration of H⁺ ions. neural circuits. (Ch 4)
9. Classify sensory receptors by stimulus, location and structure, and explain receptive fields, two-point discrimination and adaptation. (Ch 2, Ch 6)
10. Use a dermatome mapA diagram showing which spinal nerves correspond to specific skin regions. to localize a sensory deficit to a spinal root, and tell a one-root stripe from a length-dependent ‘stocking’ pattern. (Ch 1, Ch 5, Ch 6)
11. Explain how antibody-mediated demyelination (anti-MAG) produces a slow, symmetric, sensory-predominant, length-dependent neuropathy. (Ch 2, Ch 5, Ch 7)
12. Weigh evidence to separate an injury from a systemic disease, and judge how strongly the literature links Stina’s neuropathy to her lifelong inflammation. (Ch 5, Ch 7)