Module 06 Nervous System.pdf - Nervous Tissue Anatomy and...

Nervous Tissue
Anatomy and Physiology I

Objectives
•
Identify the components to the nervous system
•
Define the terms afferent and efferent
•
Compare and contrast the CNS and PNS
•
Describe the functions of the nervous system
•
Compare and contrast the function of the neuroglia
•
Identify and describe the function of the anatomical components to a neuron
•
Compare and contrast grey and white matter
•
Label neurons accordingly to their function and structure
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Nervous System: Overview
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Nervous system influences and/or controls every thought, action and emotion
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Composed of nerves which are NEURON cells
•
Neurons communicate with other neurons and different part of the body via
electrical and chemical signals
•
The signals are rapid and cause immediate responses
•
Nervous system is divided into 2 divisions:
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Central nervous system
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Peripheral nervous system
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Nervous System:
Divisions
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Central Nervous System (CNS)
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Brain and spinal cord
•
Integration center
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Peripheral Nervous System (PNS)
•
Autonomic nervous system is further divided into
•
Parasympathetic nervous system
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Sympathetic nervous system
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Afferent (s ensory ) division
•
Efferent ( motor ) division
4

Components of the nervous system.

Functional Divisions of the Nervous System
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Sensory functions
Sensory input
Afferent division of PNS
Integration/ Processing
Neural integration
CNS acts as the control
center
Responding (Output)
Motor output
Efferent division of PNS
These 3 Basic functions overlap:
✓ Normal and abnormal function of the nervous system corresponds to these three
functions

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Cells in the
Nervous system
1.
Neurons (aka nerve cells)
2.
Neuroglia cell
•
Neuroglia cells protect, support and
assist the function of neuron cells
•
There are 6 different types of
neuroglia cells. (4 in CNS; 2 in PNS)
✓
Outnumber neurons 10:1
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Neuroglia cells
1.
Astrocytes:
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Support/brace neurons and connect them
to capillaries to gain nutrients
2.
Microglial cells :
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Act as an immune cell and assist
damaged/dying neurons
3.
Ependymal cells:
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Help form the blood-brain barrier
4.
Oligodendrocytes:
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Form myelin (fatty) sheaths around the
axons of neurons in CNS
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Nerve Tissue: PNS
Neuroglia cells
5.
Satellite cells
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Surround cell body of neuron
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Assist with connecting PNS
neurons to capillaries to gain
nutrients
6.
Schwann cells
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Form myelin sheaths around
axons in the PNS
•
Similar in function to the
oligodendrocytes
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Neurons
•
Main cell of the nervous system
•
It is the functional and structural unit
of the nervous system
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Conduct nerve impulses (aka action
potentials ) from area of the body to
another
•
Found in the CNS and PNS
✓
Surrounding neurons are the
neuroglia cells (glia cells)
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Nerve Tissue:
Neuron
•
Although Neurons are long and have a
unique shape
•
They consist of a plasma membrane,
cytoplasm, organelles and a nucleus