anatomy and physiology of nerve cells for nurses

1. DNUR 3012 1
ANATOMY PHYSIOLOGY
IV
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Prepared by: Miss Nadiah Shamsuddin

2. LEARNING OBJECTIVES
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 At the end of the learning session, students
will able to:
 Describe the histological characteristic and the
functions of neurons and neuroglia.
 Distinguish between gray matter and white
matter.
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4. Introduction
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 Nervous tissue consist of two types of cells:
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neurons
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6. NERVE CELLS (NEURON)
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 Specific cells that transport electrical nerve
impulse.
 Transport impulse from one part to others part of
body.
 Property:
 Electrical excitability (ability to produce action potential
and impulse in response stimuli).
 Once they arise, action potentials propagate from one
point to the next along the plasma membrane due to the
presence of specific types of ion channels.
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8. Nerve Cells
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 Nerve fiber is a general term for any neuronal
process (dendrite or axon)
 The site of communication between two neurons
or between a neuron and an effectors cell is called
a synapse.
 (Neuron  synapse  neuron)
 Impulses transmit into neuron at synapse through
dendrite process and carry incoming impulse
towards cell bodies. Then transfer away from cell
body by axon.
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9. CELL BODY
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 Contains:
 Nucleus
 Surrounded by cytoplasm that includes typical
organelles such as:
 lysosomes, mitochondria and a Golgi complex
 Nissl bodies (prominent cluster of rough
endoplasmic reticulum) :
 sites of protein synthesis in neurons that was
used to replace cellular components, as a
material for growth of neurons and to regenerate
damaged axons in the PNS.
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10. Cell body
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 Characteristics:
 Different sizes with others
 Protoplasma have granules
 Neurons cells cannot divide like others cell body
 Form grey matter in brain and spinal cord
 Cells have one or more fibers (axons and
dendrite) will form white matter nervous system’s
organs .
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11. DENDRITE
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 Dendrite’s shorter processes terminating mostly
near the nerve cell body. They touch the others
neuron at synapse.
 Are conductive in nature :
 receive and carry incoming impulses towards cell
bodies.
 Have same structures like axons, but are usually
shorter and branching.
 In motor neuron, they forms part of synapses.
 In sensory neuron, they form the sensory
receptors that respond to specific stimuli.
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13. AXON
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 Each neuron has one axon.
 Axon may have branches along their length
known as axon collaterals.
 Axon collaterals is divide into many fine
processes known as axon terminals.
 Axon terminals:
 Longer than dendrites , sometimes about 1
metre.
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15. AXON
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 Has a long central core of cytoplasma called
axosplasma .
 The cytoplasma is surrounded by plasma
membrane axolemma.
 Together axoplasma with axolemma is called
as axis cylinder of the nerve fiber.
 Axon:
 the conducting region of the neuron.
 It generates nerve impulses and transmit them
(typically away from the cell body.)
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16. AXON
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 Insulated by myelin sheath
It gives white colour to the nerve fiber.
 Has a series of Schwann cell plasma membrane
and also known as neurolemma.
 There are tiny areas of exposed axolemma
between adjacent Schwann cells, called nodes of
Ranvier.
 Nodes of Ranvier:
 Assist in rapid transmission of nerve impulse.
(the speed of transmission of nerve impulse slower in
non-myelinated fibers.) DNUR 3012

17. Functions of Myelin Sheath
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18. Neurolemma
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 A series of Schwann cell plasma membrane -
 Thin membrane surrounding the myelin sheath
that found only around axons in the Peripheral
Nervous Sytem.
 When the axon is injured, neurolemma assists
regenerations.
 It forms a regeneration tube that guides and
stimulates growth of the axon.
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19. Properties of neuron
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20. Classification of neuron
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22. Classification of neuron
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23. Classification of neuron
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24. Classification of neuron
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Classification of neuron
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27. Nerve Impulse
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 The electrical activity in the membrane of a
neuron.
 Ways by which information is transmitted
within the nervous system along the axons of
the neurons.
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28. Types of neuron
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29. Types of neuron: Sensory or
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Afferent Nerves
 Nerve that transmit impulse from peripheral body
through spinal cord to the brain to be interprets.
 Example: from skin.
 When action potentials are generated by sensory
receptors on the dendrites of these neurons, they
are transmitted to the spinal cord by the sensory
nerve fibers.
 The impulse may then pass to the brain or to
connector neurons of reflex arcs in the spinal
cord.
 Sensory receptors  action potentials 
dendrites  sensory nerve fibers  spinal cord
 brain / connector neuron of spinal cord.
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30. Types of neuron: Sensory or
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Afferent Nerves
 Sensory nerves from peripheral nerve are
non-myelinated and not have neurolemma.
From small division called as sensory nerve
ending.
 Stimulation; pain, hot temperature  impulse
transmit to sensory nerve  brain
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32. Types of neuron: Motor or Efferent
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Nerves
 Nerve that send impulse from brain to spinal
cord. Then it goes to skeletal muscle to
contract.
 Brain  spinal cord  skeletal muscle
(contract).
 The nearer motor nerve to muscle, it lost its
myelin sheath and neurolemma.
 The nerve branches into filament and ends at
Motor End Plate.
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33. NEUROGLIA
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 It is about half the volume of the Central
Nervous System (50%).
 It held nervous tissue together.
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34. 6 Types of Neuroglia
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35. Differences between Neuroglia &
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Neuron
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36. General Functions of Neuroglia
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37. Neuroglia: Astrocytes
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38. Neuroglia: Oligodendroglia /
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oligodendrocyte
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39. Neuroglia: Microglia
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40. Neuroglia: Ependymal cells
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