1. The Nervous System

2. Protection of the Central Nervous System
Scalp and skin

3. Protection of the Central Nervous System
Figure 7.17a

4. Meninges Dura mater Double-layered external covering Periosteum—
Meningeal Layer-
Folds inward in several areas

5. Meninges
Arachnoid layer
Pia mater

6. Meninges
Figure 7.17b

7. 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

8. Ventricles and Location of the Cerebrospinal Fluid
Figure 7.18a–b

9. Ventricles and Location of the Cerebrospinal Fluid
Figure 7.18c

10. Hydrocephalus in a Newborn
Figure 7.19

11. Blood-Brain Barrier
Includes the least permeable capillaries of the body
Excludes many potentially harmful substances
Useless as a barrier against some substances

12. Traumatic Brain Injuries
Concussion
Contusion
Cerebral edema

13. Cerebrovascular Accident (CVA)
Commonly called a stroke
The result of a ruptured blood vessel supplying a region of the brain
Brain tissue supplied with oxygen from that blood source dies

14. 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

15. Spinal Cord
Extends from the foramen magnum of the skull to the first or second lumbar vertebra

16. Spinal Cord Anatomy
Figure 7.20 (1 of 2)

17. Spinal Cord Anatomy
Figure 7.20 (2 of 2)

18. Spinal Cord Anatomy Internal gray matter is mostly cell bodies
Dorsal (posterior) horns
Anterior (ventral) horns
Gray matter surrounds the central canal
Exterior white mater—conduction tracts

19. Spinal Cord Anatomy
Figure 7.21

20. Spinal Cord Anatomy Meninges cover the spinal cord
Spinal nerves leave at the level of each vertebrae
Dorsal root
Ventral root

21. Pathways Between Brain and Spinal Cord
Figure 7.22

22. Peripheral Nervous System (PNS)
Nerves and ganglia outside the central nervous system
Nerve

23. PNS: Structure of a Nerve
Endoneurium surrounds each fiber
Groups of fibers are bound into fascicles by perineurium
Fascicles

24. PNS: Structure of a Nerve
Figure 7.23

25. PNS: Classification of Nerves
Mixed nerves
Sensory (afferent) nerves
Motor (efferent) nerves

26. PNS: Cranial Nerves
12 pairs of nerves that mostly serve the head and neck
Only the pair of vagus nerves extend to thoracic and abdominal cavities

27. PNS: Cranial Nerves I Olfactory II Optic III Oculomotor nerve
IV Trochlear

28. PNS: Cranial Nerves V Trigeminal VI Abducens VII Facial
VIII Vestibulocochlear

29. PNS: Cranial Nerves IX Glossopharyngeal nerve— X Vagus nerves—
XI Accessory nerve—
XII Hypoglossal

30. PNS: The Cranial Nerves
Table 7.1 (1 of 4)

31. PNS: The Cranial Nerves
Table 7.1 (2 of 4)

32. PNS: The Cranial Nerves
Table 7.1 (3 of 4)

33. PNS: The Cranial Nerves
Table 7.1 (4 of 4)

34. PNS: Distribution of Cranial Nerves
Figure 7.24