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At the completion of this chapter, the reader will be able to:

  1. Describe the central nervous system (CNS) and peripheral nervous system (PNS) components.

  2. Describe the anatomic and functional organization of the nervous system.

  3. Describe the various components and distributions of the cervical, brachial, and lumbosacral plexuses.

  4. Describe the difference between balance and proprioception.

  5. Describe the role that proprioception plays in function.

  6. Describe and differentiate among the various joint mechanoreceptors.

  7. Recognize the characteristics of a lesion to the CNS.

  8. Outline the neurophysiology of pain and the methods by which pain is controlled.

  9. Define concussion and describe its associated signs and symptoms.

  10. List the findings and impairments associated with the more common peripheral nerve lesions.

  11. Perform a comprehensive examination of the neurologic system.

  12. Describe some of the common pathologies of the nervous system.



To perform a comprehensive neuromusculoskeletal examination, the clinician must clearly understand the anatomy, physiology, and function of the nervous system’s various components and recognize those signs and symptoms that indicate compromise to the nervous system.

The nervous system is composed of only two principal types of cells—neurons and supporting cells. The neuron, classified according to its structure or function, serves to store and process information and is the nervous system’s functional unit. The neuron’s supporting cell, called the neuroglial cell, or simply glial cell, provides structural and metabolic support.1 Unlike many cells, neurons cannot divide by mitosis, but they do have some capability to regenerate, whereas glial cells retain less mitotic ability.


The human nervous system can be subdivided into two anatomic divisions: the CNS, comprising the brain and the spinal cord, and the PNS, formed by the nerves and ganglia (a cluster of nerve cell bodies located outside the CNS). The PNS is further subdivided into somatic and autonomic divisions. The somatic division, which includes the cranial nerves (CNs), except for cranial II, and the spinal nerves, innervates the skin, muscles, and joints, while the autonomic division innervates the glands and the smooth muscle of the viscera and the blood vessels.1

Neurons can broadly be divided into four types based on anatomical and functional criteria2:

  • Aα fibers: Thick, myelinated fibers that transmit signals to and from muscles.

  • Aβ fibers: Thick, myelinated fibers conducting sensations such as touch and proprioception.

  • Aδ fibers: Thin, myelinated fibers transmitting nociceptive signals evoked by stimuli such as cold and pinprick.

  • C fibers: Small-diameter, unmyelinated nerve fibers subserving nociception evoked by heat or mechanical stimuli, as well as innocuous temperature changes (e.g., warm detection) and itching. C fibers can be further subdivided into four main groups:

    • C-polymodal fibers, activated by mechanical, thermal, and chemical stimuli.

    • Mechanoreceptors, activated by specific modalities.

    • Low-threshold C fibers, mediating pleasant touch.

    • Silent (sleeping) nociceptors, not normally activated by thermal or mechanical stimuli but become sensitized after exposure ...

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