1. Introduction to
Nervous System

2. Objectives What is the basic function of Nervous System.
Classify Nervous System.
Define neuron.
Classify neuron on the basis of Structure, Function, Location and Length.
Define Synapse.
What are different types of synapses.

3. Objectives
What are the different types of Supporting Cells of Nervous system.
Define Myelination.
How a typical Spinal Nerve forms.
What are the different coverings of a spinal nerve.

4. Basic Functions of the Nervous System
Three Basic Functions
1-Sensation= Sensory functions:
Sensory receptors detect both internal and external stimuli.
Functional unit: Sensory or Afferent Neurons

5. Basic Functions of the Nervous System
2-Integration:
CNS integrates sensory input and makes decisions regarding appropriate responses.
Functional Unit: Interneurons or Association Neurons of the Brain and Spinal cord.

6. Basic Functions of the Nervous System
3- Motor functions=Reaction:
Motor Functions: Response to integration decisions.
Functional Unit: Motor or Efferent Neurons
The activation of muscles or glands (Via Neurotransmitters).

7. Organization of the Nervous System to supply the three basic functions

8. Classification of Nervous System
1. Central
a. Brain
b. Spinal Cord
2. Peripheral
a. 12 Pairs of Cranial Nerves
b. 31 Pairs of Spinal Nerves

10. Organization of the CNS
Gray Matter: Contains neuron cell bodies
White Matter: Contains cell extensions organized into tracts

11. Classification of Nervous Systemk e l t a ( o m i c ) y p h P r s A u n N v

12. Structure of a Neuron Dendrites: Carry nerve
impulses toward cell body.
Receive stimuli from synapses or sensory receptors.
Cell Body: Contains nucleus and nissl bodies, a form of rough endoplasmic reticulum.
Axon: Carry nerve Impulses away from the cell bodies. Axons interact with muscle, glands, or other neurons.

13. A developing Brain cell
NONEXCITABLE CELL
EXCITABLE CELL

14. Neuron Nucleus Cell body (Soma or Perikaryon) Dendrite Axon
Schwann cell
Axon Terminal
Synaptic knobs
Node of Ranvier

15. NERVE
a group of fibers (axons) outside the CNS. The spinal nerves contain the fibers of the sensory and motor neurons. A nerve does not contain cell bodies. They are located in the ganglion (sensory) or in the gray matter : nucleus(motor).

16. TRACT
a group of fibers inside the CNS. The spinal tracts carry information up or down the spinal cord, to or from the brain. Tracts within the brain carry information from one place to another within the brain. Tracts are always part of white matter.

18. Structural Classification of Neuron
Multipolar Neuron
Bipolar Neuron
Unipolar or Pseudounipolar Neuron

19. Functional Classification of Neuron
1. Sensory Neuron

20. Functional Classification of Neuron
2. Motor Neuron:

21. Functional Classification of Neuron
3. Interneuron or Association Neuron

22. Synapse

23. A synapse is the junction between two neurons (nerve cells) or between a neuron and a gland or muscle cell. Neurotransmitters carry impulses across the tiny gap between the cells, which is called the synaptic cleft.

24. Types of Synapse

25. SYNAPSE

26. SYNAPSE

27. SYNAPSE

28. SYNAPSE

29. SYNAPSE

30. Non – Excitable or Supporting Cells or Neuroglia

31. Astrocyte

32. are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including :
1- biochemical support of endothelial cells that form the blood–brain barrier,
2- provision of nutrients to the nervous tissue,
3-maintenance of extracellular ion balance,
4- and a role in the repair and scarring process of the brain and spinal cord following traumatic injuries

33. Microglial Cell Microglia are the main resident immunological cells the CNS

34. Ependymal Cell

35. These are the epithelial cells that line the CSF-filled ventricles in the brain and the central canal of the spinal cord. The cells are ciliated simple cuboidal epithelium. Their apical surfaces are covered in a layer of cilia, which circulate CSF around the central nervous system. Their apical surfaces are also covered with microvilli, which absorb CSF. Ependymal cells are a type of Glial cell and are also CSF producing cells. Within the brain's ventricles, a population of modified ependymal cells and capillaries together form a system called the choroid plexus, which produces the CSF.

36. Oligodendrocyte

37. Schwann Cell

38. Non – Excitable or Supporting Cells

39. Myelination (CNS & PNS)

43. Spinal Nerve

44. Afferent Fiber: carry nerve impulses from receptors or sense organs towards the central nervous system.
Efferent Fiber:carry nerve impulses away from the central nervous system to effectors such as muscles or glands
Ganglion: Collection of nerve cell bodies OUTSIDE the CNS
Nucleus: Collection of nerve cell bodies inside the CNS
Plexus:a plexus is an area where nerves branch and rejoin.

45. Spinal Nerve

46. Spinal Nerve

47. Spinal Nerve

48. Coverings of Nerve