Biology 235 Human Anatomy and Physiology

Study Guide

Chapter 13
The Spinal Cord and Spinal Nerves

Objectives

After completing this chapter, you should be able to

  1. describe the protective structures and the gross anatomical features of the spinal cord.
  2. describe how spinal nerves are connected to the spinal cord.
  3. describe the components, connective tissue coverings and branching of a spinal nerve.
  4. define the term plexus, and describe the anatomical importance of a plexus.
  5. describe the clinical significance of dermatomes.
  6. describe the functions of the major sensory and motor tracts of the spinal cord.
  7. describe the functional components of a reflex arc, and explain the relationship of reflexes to homeostasis.
  8. describe several clinically-important reflexes.
  9. describe three instances of homeostatic disruption of spinal function.

Keywords and Topics

Make certain that you can define, and use in context, each of the terms listed below, and that you understand the significance of each of the concepts.

  1. Describe the protective structures and the gross anatomical features of the spinal cord.
    1. spinal cord anatomy
      1. spinal meninges (singular is meninx)
        1. epidural space
        2. dura mater
        3. arachnoid mater
        4. subdural space
        5. pia mater
        6. subarachnoid space
      2. external anatomy of the spinal cord
        1. cervical and lumbar enlargements
        2. conus medullaris
        3. filum terminale
        4. spinal nerves
        5. cauda equina
      3. internal anatomy of the spinal cord
        1. anterior median fissure
        2. posterior median sulcus
        3. gray commissure
        4. central canal
        5. anterior or ventral white commissure
        6. nuclei
        7. posterior (dorsal) gray horn
        8. anterior (ventral) gray horn
        9. lateral gray horn
        10. columns
        11. anterior (ventral) white column
        12. posterior (dorsal) white column
        13. lateral white column
        14. tract
        15. sensory (ascending) tract
        16. motor (descending) tract
  2. Describe how spinal nerves are connected to the spinal cord.
    1. roots
    2. rootlets
    3. posterior or dorsal root
    4. posterior or dorsal root ganglion
    5. anterior or ventral root
  3. Describe the components, connective tissue coverings and branching of a spinal nerve.
    1. spinal nerves
      1. mixed nerve
      2. connective tissue coverings
        1. endoneurium
        2. fascicle
        3. perineurium
        4. epineurium
      3. distribution of spinal nerves
      4. ramus (plural is rami)
      5. meningeal branch
  4. Define the term plexus, and describe the anatomical importance of a plexus.
    1. plexus
      1. cervical plexus
      2. brachial plexus
      3. lumbar plexus
      4. sacral plexus
      5. coccygeal plexus
      6. intercostal or thoracic nerves
  5. Describe the clinical significance of dermatomes.
    1. dermatome
  6. Describe the functions of the major sensory and motor tracts of the spinal cord.
    1. spinal cord physiology
      1. sensory tracts
        1. spinothalamic tracts
        2. posterior column
      2. motor tracts
        1. direct motor pathways
        2. indirect motor pathways
  7. Describe the functional components of a reflex arc, and explain the relationship of reflexes to homeostasis.
    1. reflex
      1. spinal reflex
      2. cranial reflex
      3. somatic reflex
      4. autonomic or visceral reflex
      5. reflex arc
        1. sensory receptor
        2. stimulus
        3. sensory neuron
        4. integrating center
        5. monosynaptic reflex arc
        6. polysynaptic reflex arc
        7. motor neuron
        8. effector
      6. stretch reflex
      7. muscle spindle
      8. ipsilateral reflex arc
      9. muscle tone
      10. reciprocal innervation
      11. tendon reflex
      12. tendon organ or Golgi tendon organ
      13. flexor or withdrawal reflex
      14. intersegmental reflex arc
      15. crossed extensor reflex
      16. contralateral reflex arc
  8. Describe two clinically-important reflexes.
    1. patellar reflex (knee jerk reflex)
    2. Babinski reflex
  9. Describe three instances of homeostatic disruption of spinal function.
    1. disorders
      1. spinal cord compression
      2. shingles
      3. poliomyelitis

Complete the “Chapter Review and Resource Summary” at the end of the chapter.

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