1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 13, part 1 The Spinal Cord and Spinal Nerves

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Discuss the structure and functions of the spinal cord. Describe the three meningeal layers that surround the CNS. Describe the major components of a spinal nerve and relate their distribution to their regions of innervation. Discuss the significance of neuronal pools. Describe the steps in a neural reflex. Explain how reflexes interact to produce complicated behaviors.

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 13-1 General Organization of the Nervous System

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings CNS Brain and spinal cord In the white matter, axons arranged in tracts and columns PNS Remainder of nervous tissue Divisions of the Nervous System

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.1 Figure 13.1 An Introduction to the Anatomical Organization of the Nervous System

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 13-2 Gross Anatomy of the Spinal Cord

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Localized enlargements provide innervation to limbs 31 segments each segment has a pair of dorsal roots and a pair of ventral roots Filum terminale Conus medularis Spinal nerves extend off cord Mixed nerves Adult spinal cord

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.3 Figure 13.3 Gross Anatomy of the Adult Spinal Cord

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Spinal meninges Provide physical stability and shock absorption Three layers Dura mater Arachnoid Pia mater

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Covers spinal cord Tapers to coccygeal ligament Epidural space separates dura mater from walls of vertebral canal Dura mater

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.4a Figure 13.4 The Spinal Cord and Spinal Meninges

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.4b Figure 13.4 The Spinal Cord and Spinal Meninges

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Arachnoid Interior to dura mater are the subdural space, the arachnoid and the subarachnoid space Subarachnoid space contains CSF

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Pia mater Meshwork of elastin and collagen fibers Innermost meningeal layer Denticulate ligaments extend from pia mater to dura mater

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.6 The Cervical Spinal Cord Figure 13.6

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sectional anatomy of the spinal cord White matter is myelinated and unmyelinated axons Gray matter is cell bodies, unmyelinated axons and neuroglia Projections of gray matter toward outer surface of cord are horns

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.7a Figure 13.7 The Sectional Organization of the Spinal Cord

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 13.7b Figure 13.7 The Sectional Organization of the Spinal Cord

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Posterior gray horn contains somatic and visceral sensory nuclei Anterior gray horns deal with somatic motor control Lateral gray horns contain visceral motor neurons Gray commissures contain axons that cross from one side to the other Horns of spinal cord

20. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings White matter Divided into six columns (funiculi) containing tracts Ascending tracts relay information from the spinal cord to the brain Descending tracts carry information from the brain to the spinal cord Animation: Spinal cord dissections PLAY