1. Fundamentals of the Nervous System and Nervous Tissue
Chapter 11
Fundamentals of the Nervous System and Nervous Tissue
Part A

2. Nervous System
The master controlling and communicating system of the body
Functions:
1-Sensory input –
Figure 11.1

3. Nervous System
2-Integration –
3- Motor output –
Figure 11.1

5. Organization of the Nervous System
Central nervous system (CNS)
Peripheral nervous system (PNS)

6. Two principal cell types
Neurons –
Supporting cells –

7. Supporting Cells: Neuroglia (glia)
Provide a supportive scaffolding for neurons
Segregate and insulate neurons

8. Astrocytes
Figure 11.3a

9. Astrocytes Most abundant, versatile, and highly branched glial cells
They cling to neurons and cover capillaries

10. Microglia and Ependymal Cells
Figure 11.3b, c

11. Microglia and Ependymal Cells
Ependymal cells – squamous- to columnar-shaped cells

12. CEREBROSPINAL FLUID- SHOWN CIRCULATING BY ARROWS
Figure 7.17b
Slide 7.47b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

13. Protection of the Central Nervous System
Figure 7.16a
Slide 7.44a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

14. CEREBROSPINAL FLUID Slide 7.47b Figure 7.17b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

15. Oligodendrocytes, Schwann Cells, and Satellite Cells
IN CNS
IN PNS
Figure 11.3d, e

16. Oligodendrocytes –
Schwann cells (neurolemmocytes) –
Satellite cells-

17. Neuron
Anatomy

18. Neurons (Nerve Cells) functions in:
Composed of a body, axon, and dendrites
Long-lived (over 100 yrs), amitotic, and have a high metabolic rate
functions in:
Electrical signaling
Cell-to-cell signaling during development

20. Nerve Cell Body (Soma) nucleus - Nucleolus-
Where outgrowth of neuronal processes
There are no centrioles (amitotic nature)
Nissl bodies-
Axon hillock –

21. Processes Armlike extensions from the soma Called in the CNS
Called in the PNS
Two types:

23. Dendrites of Motor Neurons
Short, tapering, and branched
They are the receptive, or input, regions of the neuron

24. Axons: Structure
Slender processes of uniform diameter arising from the hillock
Long axons are called nerve fibers
Usually there is only one unbranched axon per neuron
Axonal terminal – branched terminus of an axon

25. Axons: Function Generate and transmit action potentials
Secrete neurotransmitters from the axonal terminals

26. Neuron Classification
Figure 7.6
Slide 7.15
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

27. Structural Classification of Neurons
Multipolar neurons –
Figure 7.8a
Slide 7.16a
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

28. Structural Classification of Neurons
Bipolar neurons –
Figure 7.8b
Slide 7.16b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

29. Structural Classification of Neurons
Unipolar neurons –
Figure 7.8c
Slide 7.16c
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

31. Nodes of Ranvier (Neurofibral Nodes)
Gaps in the myelin sheath between adjacent Schwann cells
They are the sites where collaterals can emerge (see 1st neuron pic)

32. Myelin Sheath and Neurilemma: Formation
Figure 11.5a-d

33. In MS, myelin is lost in multiple areas, leaving scar tissue called sclerosis.
These damaged areas are also known as plaques or lesions.

34. Myelin sheath is green
Axon is yellow

35. Myelin Sheath
Whitish, fatty (lipoprotein), segmented sheath around most long axons
It functions in:

36. Formed by Schwann cells in the PNS A Schwann cell:
Envelopes an axon in a trough
Encloses the axon with its plasma membrane
Concentric layers of membrane make up the myelin sheath
Neurilemma – remaining nucleus and cytoplasm of a Schwann cell

37. Unmyelinated Axons
A Schwann cell surrounds nerve fibers but coiling does not take place
SEE HW PG. 256 #12 A

38. Axons of the CNS Both myelinated and unmyelinated fibers are present
Myelin sheaths are formed by
Nodes of Ranvier are widely spaced

39. Regions of the Brain and Spinal
White matter –
Gray matter –
Basal nuclei –

40. Gray matter
White matter