Download Nervous Tissue Lab

Divisions of the Nervous System
• Central Nervous
Nervous Tissue Lab
BIO 137 Anatomy and Physiology I
Mary Catherine Flath, Ph.D.
System
• brain
• spinal cord
• Peripheral Nervous
System
• peripheral nerves
• cranial nerves
• spinal nerves
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Functions of Nervous System
Sensory Function (PNS)
• sensory receptors gather
information (are stimulated)
• information is carried as sensory Motor Function (PNS)
• decisions are acted
impulse on sensory neurons to the
upon
CNS
• motor impulses are
Integrative Function (CNS)
carried on motor
• sensory information is
neurons to effectors
integrated. (i.e. used to create
(responsive body parts)
• sensations
• memory
• thoughts
• decisions)
Copyright 2016 Dr. Mary Cat Flath
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Divisions of the Nervous System
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Divisions of Peripheral Nervous
System
Sensory Division
• picks up sensory information and delivers it to the CNS
Motor Division
• carries information from CNS to effectors:
•muscles and glands
Divisions of the Motor Division
Somatic – carries information to skeletal
muscle
Autonomic – carries information to smooth
muscle, cardiac muscle, and glands
Copyright 2016 Dr. Mary Cat Flath
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Divisions of the Nervous System
CENTRAL NERVOUS SYSTEM (Brain and
Spinal Cord; Interneurons)
PERIPHERAL NERVOUS SYSTEM (Cranial and
Spinal Nerves
 SENSORY/AFFERENT NEURONS (INPUT)
 MOTOR/EFFERENT NEURONS (OUTPUT)
 SOMATIC (Effectors: skeletal muscle)
 AUTONOMIC (Effectors: smooth muscle,
cardiac muscle, glands)
 PARASYMPATHETIC (maintains
homeostasis; acetylcholine)
 SYMPATHETIC (Fight or Flight;
norepinephrine)
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Nervous Tissue
Nervous Tissue
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Neurons with multiple extensions
surrounded by neuroglial cells.
Locations:
 Brain and spinal cord (CNS)
 Nerves (PNS)
Function: Sensory, Integration, and
motor
No reproduction of cells.
Nervous Tissue
is composed of
• neurons
• neuroglial cells
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Neuron Structure
Neuron Structure
Copyright 2016 Dr. Mary Cat Flath
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Copyright 2016 Dr. Mary Cat Flath
Transmission of a Nerve Impulse
within a Neuron (Electrical Impulse)
Neuron Structure
SEM
Copyright 2016 Dr. Mary Cat Flath
 Starts
on a Dendrite
 Continues through the Cell
Body
 Continues down the Axon
 And finally into Axonal
terminals/Synaptic Knobs
Copyright 2016 Dr. Mary Cat Flath
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NERVOUS TISSUE ~HP
NEUROGLIAL CELLS
LIGHT MICROGRAPHS
OF NERVOUS TISSUE
SLIDE IS LABELED “GIANT
MULTIPOLAR NEURONS”
CELL BODY OF NEURON
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
TEM OF AXONS (CROSS-SECTION)
Myelination of Axons
PNS: Schwann cells
(neuroglial cells in
PNS) myelinate
axons
TEM
CNS:
Oligodendrocytes
(neuroglial cells in
CNS) myelinate
axons
Copyright 2016 Dr. Mary Cat Flath
10-8
Copyright 2016 Dr. Mary Cat Flath
Neuroglial Cells
Types of Neuroglial Cells
Schwann Cells
• PNS
• myelinating cell
Oligodendrocytes
• CNS
• myelinating
cell
Microglia
• CNS
• phagocytic cell
Astrocytes
• CNS
• support and nourish
neurons
Ependyma
• CNS
• ciliated
• line central canal of spinal
cord and ventricles of brain
Copyright 2016 Dr. Mary Cat Flath
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Copyright 2016 Dr. Mary Cat Flath
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Functional Classification of Neurons
Sensory Neurons
• afferent neurons
• carry impulses from sensory receptors to CNS
Interneurons
• link neurons
• multipolar
• in CNS
Motor Neurons
• multipolar
• efferent
• carry impulses away from CNS to effectors
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Structural Classification of Neurons
(we will consider all as multipolar)
Bipolar
• two processes
• eyes, ears, nose
Unipolar
• one process
• ganglia
MULTIPOLAR
• many processes
• most neurons of
CNS
Copyright 2016 Dr. Mary Cat Flath
10-9
Copyright 2016 Dr. Mary Cat Flath
Divisions of the Nervous System
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Nervous Tissue (continued)
Copyright 2016 Dr. Mary Cat Flath
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CENTRAL NERVOUS SYSTEM (Brain and
Spinal Cord; Interneurons)
PERIPHERAL NERVOUS SYSTEM (Cranial and
Spinal Nerves
 SENSORY/AFFERENT NEURONS (INPUT)
 MOTOR/EFFERENT NEURONS (OUTPUT)
 SOMATIC (Effectors: skeletal muscle)
 AUTONOMIC (Effectors: smooth muscle,
cardiac muscle, glands)
 PARASYMPATHETIC (maintains
homeostasis; acetylcholine)
 SYMPATHETIC (Fight or Flight;
norepinephrine)
Copyright 2016 Dr. Mary Cat Flath
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Peripheral Nervous System
• Definition of
a nerve: A bundle of
myelinated axons in the PNS
A NERVE IS A BUNDLE
OF MYELINATED AXONS
IN THE PNS
•Cranial nerves arise from the brain
• 12 pairs
• Spinal nerves arise from the spinal cord
• 31 pairs
• All mixed
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Structure of a Peripheral Nerve
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Peripheral Nerve (Medullated nerve)
Your peripheral nerve slide
shows both a longitudinal
section (ls) & cross section (cs)
The slide is labeled “medullated
nerve”.
Copyright 2016 Dr. Mary Cat Flath
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Longitudinal Section
 You can see myelinated axons and
Nodes of Ranvier
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Cross-Section
 You can see connective tissue
coverings
Copyright 2016 Dr. Mary Cat Flath
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Longitudinal Section of a Peripheral
Nerve (LM)
SEM
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Divisions of the Nervous System
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Your third slide in Nervous
Tissue is a “motor unit.”
The slide is labeled “Motor Nerve
Endings.” (You saw this slide when
you studied the muscular system).
Copyright 2016 Dr. Mary Cat Flath
STIMULATION OF SKELETAL
MUSCLE FIBERS
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CENTRAL NERVOUS SYSTEM (Brain and
Spinal Cord; Interneurons)
PERIPHERAL NERVOUS SYSTEM (Cranial and
Spinal Nerves
 SENSORY/AFFERENT NEURONS (INPUT)
 MOTOR/EFFERENT NEURONS (OUTPUT)
 SOMATIC (Effectors: skeletal muscle)
 AUTONOMIC (Effectors: smooth muscle,
cardiac muscle, glands)
 PARASYMPATHETIC (maintains
homeostasis; acetylcholine)
 SYMPATHETIC (Fight or Flight;
norepinephrine)
Copyright 2016 Dr. Mary Cat Flath
Neuromuscular Junction
EACH SKELETAL MUSCLE FIBER IS
STIMULATED TO CONTRACT BY A BRANCH OF
A MOTOR NEURON
A MOTOR UNIT IS DEFINED AS
 ONE MOTOR NEURON
 MANY SKELETAL MUSCLE FIBERS
A NEUROMUSCULAR JUNCTION IS WHERE THE
MOTOR NERVE ENDING MEETS THE
SARCOLEMMA OF THE SKELTAL MUSCLE
FIBER
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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MOTOR NERVE ENDINGS (MOTOR UNIT) ~LOW
MUSCLE FIBERS
Light Micrographs (LMs)
of Motor Units
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
MOTOR NERVE ENDINGS (MOTOR UNIT) ~LOW~
MOTOR NERVE ENDINGS (MOTOR UNIT) ~LOW~
BRANCHING MOTOR NEURON
NEUROMUSCULAR JUNCTIONS
Copyright 2016 Dr. Mary Cat Flath
MOTOR NERVE ENDINGS (MOTOR UNIT) ~HIGH~
Copyright 2016 Dr. Mary Cat Flath
Nerve Fiber Classification
• Sensory
Nerves – conduct sensory impulses
into CNS
• Motor Nerves – conduct motor impulses
from CNS to muscles or glands
• Mixed Nerves – contain both sensory nerve
fibers and motor nerve fibers; most
nerves and all spinal nerves
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Divisions of the Nervous System
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
CENTRAL NERVOUS SYSTEM (Brain and
Spinal Cord; Interneurons)
PERIPHERAL NERVOUS SYSTEM (Cranial and
Spinal Nerves
 SENSORY/AFFERENT NEURONS (INPUT)
 MOTOR/EFFERENT NEURONS (OUTPUT)
 SOMATIC (Effectors: skeletal muscle)
 AUTONOMIC (Effectors: smooth muscle,
cardiac muscle, glands)
 PARASYMPATHETIC (maintains
homeostasis; acetylcholine)
 SYMPATHETIC (Fight or Flight;
norepinephrine)
Cranial Nerves (studied later)
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Spinal Nerves (studied later)
• mixed
nerves
• 31 pairs
• 8 cervical (C1 to C8)
• 12 thoracic (T1 to T12)
• 5 lumbar (L1 to L5)
• 5 sacral (S1 to S5)
• 1 coccygeal (Co)
See how you do identifying
the following structures.
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Neuron Structure
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Motor neuron
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Longitudinal Section of a Peripheral
Nerve (LM)
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
MOTOR NERVE ENDINGS (MOTOR UNIT) ~LM; LOW~
BRANCHING MOTOR NEURON
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
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Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Copyright 2016 Dr. Mary Cat Flath
Good luck studying!!!
Copyright 2016 Dr. Mary Cat Flath
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