1. PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART C 7 Protection of the Central Nervous System

2. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protection of the Central Nervous System  Scalp and skin  Skull and vertebral column  Meninges  Cerebrospinal fluid (CSF)  Blood-brain barrier

3. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protection of the Central Nervous System Figure 7.17a

4. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meninges  Dura mater  Double-layered external covering  Periosteum—attached to inner surface of the skull  Meningeal layer—outer covering of the brain  Folds inward in several areas

5. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meninges  Arachnoid layer  Middle layer  Web-like  Pia mater  Internal layer  Clings to the surface of the brain  Subarachnid space- filled with cerebrospinal fluid

6. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meninges Figure 7.17b

7. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meningitis  Inflammation of the meninges  Can be viral or bacterial  Called encephalitis when it causes brain inflammation  Diagnosed by taking sample of cerebrospinal fluid from the subarachnoid space

8. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebrospinal Fluid (CSF)  Similar to blood plasma composition  Formed by the choroid plexus  Forms a watery cushion to protect the brain  Circulated in arachnoid space, ventricles, and central canal of the spinal cord  Usually forms and drains at the same rate so normal pressure and volume is maintained

9. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.18a–b Ventricles and Location of the Cerebrospinal Fluid

10. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Ventricles and Location of the Cerebrospinal Fluid Figure 7.18c

11. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Hydrocephalus in a Newborn  Hydrocephalus  CSF accumulates and exerts pressure on the brain if not allowed to drain Figure 7.19

12. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Blood-Brain Barrier  Includes the least permeable capillaries of the body  Excludes many potentially harmful substances  Useless as a barrier against some substances  Fats and fat soluble molecules  Respiratory gases  Alcohol  Nicotine  Anesthesia

13. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Traumatic Brain Injuries  Concussion  Slight brain injury  No permanent brain damage  Contusion  Nervous tissue destruction occurs  Nervous tissue does not regenerate  Cerebral edema  Swelling from the inflammatory response  May compress and kill brain tissue

14. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Traumatic Brain Injuries  Intracranial hemorrhage  Bleeding from a ruptured blood vessel

15. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cerebrovascular Accident (CVA)  Commonly called a stroke  3 rd leading cause of death in US  The result of a ruptured blood vessel supplying a region of the brain  Brain tissue supplied with oxygen from that blood source dies  Loss of some functions or death may result

16. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Alzheimer’s Disease  Progressive degenerative brain disease  Mostly seen in the elderly, but may begin in middle age  Structural changes in the brain include abnormal protein deposits and twisted fibers within neurons  Victims experience memory loss, irritability, confusion, and ultimately, hallucinations and death  Associated with a shortage of Ach and may run in families

17. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Parkinson’s Disease  Caused by basal nuclei problem  Dopamine deprived  Have a persistent tremor at rest

18. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Huntington’s Disease  Genetic disease  Massive degeneration of basal nuclei  Wild jerky movements

19. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord  Extends from the foramen magnum of the skull to the first or second lumbar vertebra  31 pairs of spinal nerves arise from the spinal cord  Cauda equina is a collection of spinal nerves at the inferior end

20. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy Figure 7.20 (1 of 2)

21. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy Figure 7.20 (2 of 2)

22. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy  Internal gray matter is mostly cell bodies  Looks like letter H or butterfly  Dorsal (posterior) horns-  If dorsal root damaged, lose sensation from that area of bode  Anterior (ventral) horns-  Gray matter surrounds the central canal  Central canal is filled with cerebrospinal fluid  Exterior white mater—conduction tracts  Dorsal, lateral, ventral columns

23. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy  Flaccid Paralysis  Damage to ventral root causes paralysis of muscles served  No voluntary movement  Spastic Paralysis  Spinal cord is transected or cut  Loss of feeling  Unvoluntary movement is possible and lose feeling  Quadriplegic affects all four limbs  Paraplegic- affects only legs

24. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy Figure 7.21

25. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Cord Anatomy  Meninges cover the spinal cord  Spinal nerves leave at the level of each vertebrae  Dorsal root  Associated with the dorsal root ganglia— collections of cell bodies outside the central nervous system  Ventral root  Contains axons

26. Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Pathways Between Brain and Spinal Cord Figure 7.22