1. Central Nervous System
Protecting the CNS
Spinal Cord

3. Components of the CNS
Spinal Cord
Brain Stem
Cerebellum
Cerebrum
Brain

4. Protecting the Brain & Spinal Cord
Protected provided by:
1) Bone (skull & vertebrae)

5. Protecting the Brain & Spinal Cord
Protected provided by:
1) Bone (skull & vertebrae)
2) Membranes (meninges)

6. The Meninges in the Brain

7. Meninges in the Spinal Cord
Pia Mater
Arachnoid Mater
Dura Mater

8. Protecting the Brain & Spinal Cord
Protected provided by:
1) Bone (skull & vertebrae)
2) Membranes (meninges)
3) Watery Cushion (cerebrospinal fluid)

9. Cerebrospinal Fluid (CSF)
Greatly reduces brain weight
Fills layer between _______ and ______ mater

10. Formation & Circulation of CSF

13. Protecting the Brain & Spinal Cord
Protected provided by:
1) Bone (skull & vertebrae)
2) Membranes (meninges)
3) Watery Cushion (cerebrospinal fluid)
4) Blood-Brain Barrier

14. The Blood-Brain Barrier

15. The Blood-Brain Barrier
Why is there a blood-brain barrier?
Capillaries have VERY low permeability
Permeable to O2, CO2, glucose

16. Central Nervous System
Protecting the CNS
Spinal Cord

17. The Spinal Cord
Foramen magnum - L2
31 spinal nerves

18. Dorsal & Ventral Roots of PNS
Dorsal Root – Aggregation of afferent axons from:

19. Dorsal & Ventral Roots of PNS
Dorsal Root – Aggregation of afferent axons from:
Ventral Root – Aggregation of efferent axons to:

20. The Spinal Pathways Information can move in 3 directions:
Ascending - to brain
Descending - from brain
Transverse – across the spine

21. The Spinal Reflex Involves transverse spinal pathway
Interneurons link some sensory and motor neurons
Common example:
1) knee-jerk response (patellar reflex)

22. The Patellar Stretch Reflex