1. Histology and Gross Anatomy of the Nervous System
Lab 9
Histology and Gross Anatomy of the Nervous System

2. Lab 9 Activities
Identify neuron, pyramidal cell, Purkinje cell, and peripheral nerve slides
Identify boldfaced structures on brain models
Identify specified parts in lab manual on sheep brain dissection
Identify cranial nerves (by name + number I - XII)

3. Parts of a Neuron
Soma
Dendrites
Axon

4. Cell Body (Soma) Contains the usual cellular organelles
Primary site of synthesis & metabolism
Cell membrane contains receptors to respond to stimuli
Cell membrane transmits graded potentials
Most cell bodies are located within the CNS
clusters of neuron cell bodies in the CNS are called nuclei
clusters of neuron cell bodies in the PNS are called ganglia

5. Dendrites Short, tapering, highly branched processes Not myelinated
Contain some cell organelles
Cell membrane contains receptors to respond to stimuli
Transmit graded potentials towards the soma

6. Axons (nerve fiber)
Originate at a cone-shaped region – the axon hillock
A single process that transmits action potentials away from the soma
May be long (1 meter) or short (1 mm)
May branch (=collaterals)
Collaterals end at
axonal terminals
synapse with neurons or effector cells (muscles or glands)

7. The Myelin Sheath Lipid-rich, covering of axons
Oligodendrocytes in CNS
Neurilemmocytes in PNS
Dendrites are never myelinated
Protects & electrically insulates
Increases speed of nerve impulses
10-150x faster than unmyelinated fibers

8. structural Classifications
Neurons
structural Classifications

9. Multipolar Neuron (slide #24)
Many processes originate from soma

10. Bipolar Neuron
Two processes originate from soma

11. Unipolar Neuron
A single process originates from soma

12. Neurons
Specific types

13. Pyramidal Cells (slide #29)

14. Pyramidal Cells

15. Pyramidal Cells

16. Purkinje Cells (slide #30)

17. Purkinje Cells of Cerebellum

18. Purkinje Cells

19. Purkinje Cells
cytoskeleton stain

20. Peripheral Nerve Connective tissue elements: Epineurium (wraps nerve)
Perineurium (wraps fascicle)
Endoneurium (wraps axon & myelin sheath)

21. Nerve, cross-section (slide #28)
Epineurium
Perineurium
Endoneurium

22. Nerve, cross section, Fascicles
Epineurium
Perineurium
Endoneurium

23. Nerve, cross section, Myelinated Fibers

24. Myelinated Axons, cross-section

25. Myelinated Axons, cross-section

26. Nerve, Long Section, 40X (slide # 28)

27. Nerve, long section, 100X

28. Neurofibrilar Node Nerve, 400X

29. Neurofibrilar Node, 1000X

30. Sheep Brain Dissection
Dura mater partially removed

31. Sheep Brain Dissection
and
pia mater

32. Sheep Brain Dissection

33. Sheep Brain Dissection
Note: pituitary removed

34. Sheep Brain Dissection

35. Sheep Brain in Cross Section

36. Key to Sheep Brain in Cross Section
1. Gray Matter
2. White Matter
3. Corpus Callosum
4. Lateral Ventricle
5. Caudate Nucleus
6. Septum Pellucidum
7. Fornix
8. Optic Chiasm
9. Third Ventricle
10. Thalamus
11. Corona Radiata
12. Hippocampus
13. Cerebral Aqueduct
14. Pituitary Gland
15. Pineal Gland

37. Human Cranial Nerves

38. Human Cranial Nerves

39. End of Lab 9 Presentation