1. Histo On Your Nerves SSN Histology October 26th, 2004 Missy Walker, maw2106@columbia.edu So Young Kim, sk2298@columbia.edu

2. Node of Ranvier Perikaryon Myelin- Producing Cell So what’s in a nerve? Axon Hillock Dendrite Axon Terminal Axon Nucleus of myelin- producing cells

3. Axon vs. Dendrite Axon Dendrite NO Synthetic Machinery!

4. Nervous System Classifications

5. Spinal Cord

6. Spinal Cord: White Matter

7. Myelin Production in CNS Oligodendrocytes

8. Spinal Cord Gray Matter

9. Spinal Cord Cajal’s Silver

10. Meninges

11. Astrocytes No collagen in the CNS!!!

12. Brain

13. Cerebellum

14. Cerebellum

15. Purkinje Cell

16. Cerebral Cortex

18. Cerebellum vs. Cerebral Cx

19. Cerebellum vs. Cerebral Cortex

20. Pyramidal Cells vs. Spinal Cord Gray Matter

21. Peripheral Nervous System (PNS) Nervous tissue outside of the brain and spinal cord Somatic Nervous System Innervates skeletal muscle For conscious movement Cell bodies in CNS Autonomic Nervous System Innervates smooth muscle and glands For organ function and regulation Cell bodies in CNS and PNS Sympathetic & Parasympathetic

22. ANS - Ganglia Sympathetic GANGLIA in thorax contain: neuronal cell bodies satellite cells (support cells of the neuron) Synapses occur Presynaptic fibers myelinated Postsynaptic fibers unmyelinated

23. Enteric NS - Ganglia Myenteric plexus in ENS Within Smooth Muscle of Gut NO Collagen (as in CNS) Glial cells (no Schwann cells) Nuclei are euchromatic Gut has “mind of its own”

24. ENS Ganglion vs ANS Ganglion

25. Cross section of nerve Organization by Connective Tissues Endoneurium collagen fibers associated with individual neurons -Schwann cells within Perineurium layer(s) of connective tissue cells, create fascicles Epineurium dense cnxtive tissue binding fascicles into a bundle

26. Peripheral nerve Epineurium Perineurium Endoneurium

27. Periph nerve - longitudinal section Endoneurium Perineurium Epineurium

28. Longitudinal Section – Cajal stain

29. Peripheral Nerve – High Power (Cajal) Nodes of Ranvier Neurilemma (cytoplasm of Schwann cells) What’s the black?

30. Peripheral Nerve – High Power (H&E) What’s the purple? What’s the white?

31. Cross Section – Peripheral Nerve What’s the purple?

32. Peripheral Nerve Why is this a Nerve, not a Ganglion?

33. Key Points for PNS Ganglia –Contain cell bodies for motor ANS –Satellite cells are the supporting cell bodies (not glial, Schwann, or others of CNS) Peripheral Nerves –Schwann cells make mylin sheath –Node of Ranvier / saltatory conduction / Na channels –Endoneurium around neurons, which form fascicles –Perineurium around fascicles, which form bundles –Epineurium around bundles

34. Same or different?

36. What are these?

37. Questions 1 & 2... A B

38. Question 3... Figure A Figure B

39. Question 4...

40. Question 5...

41. Question 6...