PER 510- HUMAN PHYSIOLOGY
GUYTON & HALL TEXTBOOK OF
MEDICAL PHYSIOLOGY 14TH EDITION
BY JOHN E. HALL and MICHAEL E. HALL
Special Thank You to George E. Haynes
for Preparation of Power Point Slides
Instructor: Michael Campisi CCP
Unit Two: Membrane Physiology, Nerve, and Muscle
Chapter 46: Organization of the Nervous System, Basic Functions of Synapses, and Neurotransmitters
Chapter 5: Membrane Potentials, and Action Potentials
Additional videos in this presentation thanks to Dr. Eric Strong
LEARNING OBJECTIVES
BY THE END OF THIS PRESENTATION, THE STUDENT SHOULD BE ABLE TO:
Explain and understand the organization of the nervous system, the structure of a neuron, and the nature
of synapses
Explain and comprehend the major types of Neurotransmitters that control nerve functionality
Explain and understand the structure and function of both the Sympathetic and Parasympathetic nervous
systems
Explain the (4) four primary receptor families in cell membranes namely, cell membrane–embedded
enzymes (enzyme-linked receptors), ligand-gated ion channels, transcription factors, and G protein–
coupled receptor systems
Draw, explain, and comprehend the action potential graph for motor neurons, skeletal, smooth, and
cardiac muscle
Explain the significance of the refractory interval times particularly related to cardiac muscle
autorhythmicity
Overview of the Nervous System
-
Polarity on membranes
The nervous system is the most complex of the body systems comprising billions of Neurons surrounded by Neuroglial Connective Tissue. The
system is organized into two major divisions: CNS or Central Nervous System (Brain and Spinal Cord) and the PNS or Peripheral Nervous
System (all other nerves). Output nerves are called Efferent (Motor) while input nerves are called Afferent (Sensory).
Thirty-one (31) pairs of spinal nerves radiate off the CNS spinal cord creating the origin of the PNS. Nerves from these spinal nerves connect out CUS : bran Spinal cord
to the body as Somatic PNS nerves that monitor and control voluntary activity especially in skeletal muscle control, and Autonomic PNS nerves; ,
these nerves are predominately involuntary. The autonomic PNS nerves have two (2) motor outputs: the Sympathetic efferent motor output that
controls body tissues usually associated with physical activity or stress (Fight or Flight), and the Parasympathetic efferent motor output that
controls body tissues usually associated with the body in a less active state (Rest and Digest).
PNs: Periphery
-
unidirectional : -body cvs
to
(afferent
-
CNs to efferent
body
-
Somatic
=
Voluntary
-
Autonomic = involuntary
-
Sympathetic : fight or flight
-
Parasympathetic = rest and disest
1
, NEUROGLIAL CONNECTIVE TISSUE
Neuroglial (glial) connective tissue occupies about 60% of the nervous tissue and surrounds the neurons as a structural and functional support
system. Since it is a connective tissue, it contains a variety of specialized cells: Astrocytes, Microglial, Ependymal, Satellite, Oligodendrocyte,
-
nervous tissue : nerions
and Schwann.
ASTROCYTES MICROGLIAL EPENDYMAL SATELLITE
-
Neurostical : Support and structure
-
astrocytes -
Star shared -
hold nevrons in
place
These cells are very flat and surround
the cell body or soma of neurons within
PNS Ganglion. (A ganglion is a mass of
-
support Myelin Sheath on nevrons
These are the immune-phagocytic Ependymal cells are ciliated cells cell bodies surrounded with connective
These are star-shaped cells with multiple
amoeboid-like cells within the that line the central canal of the tissue. Ganglion act as connecting
processes. Protoplasmic astrocytes are
CNS. There main function is spinal cord and line the ventricles terminals in both the CNS and PNS.
associated with unmyelinated gray neurons
immunological; however, they may in the brain. Their main function is Satellite cells help protect the PNS
while Fibrous astrocytes are associated with
play a role in protecting the CNS to produce and circulate CSF. neuron cell body and regulate the
white myelinated neurons. Astrocytes are
form Tau and amyloid protein as exchange of material between the cell
tissues connecting cells to connect neurons -
central canal of
well. body and the surrounding ECM. They
and other body tissues to neurons. Astrocytes
may have receptors on their cell surface
are involved in releasing multiple -
immune system Spinal cora and
for virus and may be involved in
neurotransmitters and control substances that
are involved in synapse interactions, re-
function living ventricles harboring virus.
myelination of damaged white neurons,
- peripheral
initiation and control of immune responses,
-
phagocytes contain cilia to
isolation and
-
-
provide
and control and modulation of several types of Produce and more
neurotransmitter interactions at the synapse. Protection
CSf
THE NEUROGLIAL CELLS THAT FORM MYLEINATION AROUND AXONS- “THE WHITE MATTER”
OLIGODENDROCYTE - CNS SCHWANN - PNS ~
Wrap around axons full of fattytissue
,
-
allows ups so
to faster
-
oligodendrocytes = Cs
Oligodendrocytes look a lot like astrocytes but - Myelin : PNS
have less processes and are significantly
smaller. The processes of these cells attach
themselves to CNS neurons in the axon region
of the CNS neuron where they form a very thin The Schwann cell surround axons in the PNS. Unlike the oligodendrocyte in the CNS in
membrane around the axon. The membrane which its processes form a thin membrane around a large segment of the axon, the
then secretes a thin single layer of a white schwann enwraps itself like a jelly roll forming a thin multiple membrane
insulating material called myelin. wrapping which will then secrete the “White” myelin covering. The outer
This creates an electrically insulated “white membrane of the schwann cell with the nucleus forms a small bulge in the
Myelinated Sheath”, one layer thick around wrapping called the Neurolemma. The neurolemma aids the neuron in regenerating
the axon of the CNS neuron. These CNS the transmission pathway when neurons are damaged due to injury or disease.
neurons become know as “White”,
“myelinated” , or “White matter” Any
Neuron in the CNS that does not have a
myelin sheath is called “Gray”,
“unmyelinated “, or “Gray matter”
The Nodes of Ranvier
The Nodes of Ranvier are found only in
WHITE AXONS where they form gaps
-
Aps Jump from Mode torode between Myerin
between the CNS Oligodendrocyte
membranes and the PNS Schwann
cell membranes. These gaps expose -
Sulfatory conduction : wicker because of Jumps
the bare axon membranes.
The nodes are important because they
represent the regions where the ionic
conductance of the action potential
spreads.
The action potential transmission wave
appears to hop node to node in a fashion
called Saltatory Transmission
or Saltatory Conduction.
White Axons in both CNS and PNS are
often classified as “A” or “B” type axons
because they have very fast Saltatory
transmission speeds
2
, Nerve Connective Tissue
There are approximately 100-300 billion NEURONS in the nervous system. These nerve cells form an intricate neural network. Neurons are
-
transmission moves into around body
involved in a process called TRANSMISSION. They undergo an ionic disturbance called an action potential and secrete a neurotransmitter
that allows the next neuron in the connected network to either also have an action potential or inhibit the neuron from having an action potential.
Besides the neuron releasing neurotransmitter during an action potential, it also will undergo significant changes in the ICM (intracellular matrix)
biochemistry, and possibly physical changes that alter its circuit connections.
-
unipolar : one direction
STRUCTURAL VARIATIONS OF NEURONS
GRAY CNS/PNS MULTI-POLAR NEURON WHITE MYELINATED CNS MULTI-POLAR NEURON WHITE MYLEINATED PNS MULTI-POLAR NEURON
-
Bipolar= Cell body in Center branches into two
,
Soma
hilock -
Multipolor= Multiple dendrites can have axon branch several times
BI-POLAR AND UNI-POLAR (Often found in Sensory organs and receptors)
uni Bi-polar
Oligodendrocyte axun
Schwann Cell
Axon terminals
A typical Neuron has 5 parts to it: DENDRITES, SOMA, HILLOCK, AXON, and TELODENDRIA.
1) DENDRITES:
Numerous thin, short, branching processes off the cell body. They contain in their membrane receptors for - receptors for chemical messages (Neurotransmitters)
neurotransmitter molecules thus acting as a signal input. Their terminal end is referred to as a dendritic Knob.
Many dendrites are arranged so that their sodium ligand channels are deactivated as you move away from the
soma. This “decrement of electronic conduction” leads to a higher probability of greater excitory or inhibitory
effect by synapses located near the soma.
-
bind to ligand Nat Channels
-
Not flows into cell making inside
2) SOMA OR CELL BODY: -
flips charge
This is the typical eukaryotic cell region. The soma contains in its membrane receptors for neurotransmitter molecules thus
like the dendrites it is acting as a signal input.
The soma has an extensive network of rough and smooth endoplasmic reticulum called NISSL bodies. It also has a
well-developed Golgi apparatus. The soma is extremely active in producing NEUROTRANSMITTER and packaging the
neurotransmitter into vesicles. These neurotransmitter vesicles are then placed into special microtubules that
-
some= a lot of Mitochondria for ATP
extend all the way to the end of the telodendria called NEUROFIBRILS.
As the neural soma ages, it accumulates a fatty deposit within the cytosol of the soma called LIPOFUSCIN. Lipofuscin,
may over time interfere with neuron function.
vessicles made by Smooth FR
-
3) AXON HILLOCK:
> walked down axons to terminal
The axon hillock represents the tapered end of the soma. Like the dendrites and the main portion of the soma it contains in
its membrane receptors for neurotransmitter molecules thus also acting as a signal input. However, the number of
receptors for neurotransmitter in the hillock region is very little compared to the dendrite and soma membranes. -
hilock-axun body to axon is sensory
,
4) AXON:
The usually single axon propagates nerve impulses towards another neuron, a muscle
fiber, or a gland cell. The axon may be a bare, unmyelinated membrane process (GRAY)
or a covered myelinated membrane process (WHITE). The axon terminates into as many -
Axon = Voltage lates Channels
as 10,000 very thin hair-like processes called TELODENDRIA or axon terminals or terminal
boutons.
5) TELODENDRIA:
Very thin hair-like processes that form a connection between neurons called a SYNAPSE.
A synapse or synaptic cleft is an ultra microscopic (100 angstrom) space between 2
-
telondaria : Axon terminal
connecting cells. It is here, when the neuron has an action potential that the telodendria
terminal end called a telodendrial end bulb secretes neurotransmitter into the synaptic
cleft. The neurotransmitter then flows by diffusion over to the post-synaptic membrane of
the neuron, muscle cell or gland cell it is synapsed with. -
cat channels oped due to Voltage
The neurotransmitter is stored in vesicles within the telodendrial end bulb. Several
types of vesicles are found in the end bulb: EXCITOR vesicles, INHIBITOR vesicles,
DUAL (contain both Excitor and Inhibitor) vesicles. It has been observed as shown
below several release patterns: -
fuse to Vesicles to release nerrotransmitters
End-bulb has vesicles that contain both End-bulb has individual excitor vesicles and Two different end-bulbs- one releasing
Single release of either an excitor
excitor and inhibitor within them. Dual individual inhibitor vesicles. Dual release of excitor; the other releasing inhibitor
or an inhibitor
release of excitor and inhibitor excitor and Inhibitor from each vesicle
exocytosis -
nucleus determines What Neurotransmitter is released
-
inhibitory or excitatory nevron
3
GUYTON & HALL TEXTBOOK OF
MEDICAL PHYSIOLOGY 14TH EDITION
BY JOHN E. HALL and MICHAEL E. HALL
Special Thank You to George E. Haynes
for Preparation of Power Point Slides
Instructor: Michael Campisi CCP
Unit Two: Membrane Physiology, Nerve, and Muscle
Chapter 46: Organization of the Nervous System, Basic Functions of Synapses, and Neurotransmitters
Chapter 5: Membrane Potentials, and Action Potentials
Additional videos in this presentation thanks to Dr. Eric Strong
LEARNING OBJECTIVES
BY THE END OF THIS PRESENTATION, THE STUDENT SHOULD BE ABLE TO:
Explain and understand the organization of the nervous system, the structure of a neuron, and the nature
of synapses
Explain and comprehend the major types of Neurotransmitters that control nerve functionality
Explain and understand the structure and function of both the Sympathetic and Parasympathetic nervous
systems
Explain the (4) four primary receptor families in cell membranes namely, cell membrane–embedded
enzymes (enzyme-linked receptors), ligand-gated ion channels, transcription factors, and G protein–
coupled receptor systems
Draw, explain, and comprehend the action potential graph for motor neurons, skeletal, smooth, and
cardiac muscle
Explain the significance of the refractory interval times particularly related to cardiac muscle
autorhythmicity
Overview of the Nervous System
-
Polarity on membranes
The nervous system is the most complex of the body systems comprising billions of Neurons surrounded by Neuroglial Connective Tissue. The
system is organized into two major divisions: CNS or Central Nervous System (Brain and Spinal Cord) and the PNS or Peripheral Nervous
System (all other nerves). Output nerves are called Efferent (Motor) while input nerves are called Afferent (Sensory).
Thirty-one (31) pairs of spinal nerves radiate off the CNS spinal cord creating the origin of the PNS. Nerves from these spinal nerves connect out CUS : bran Spinal cord
to the body as Somatic PNS nerves that monitor and control voluntary activity especially in skeletal muscle control, and Autonomic PNS nerves; ,
these nerves are predominately involuntary. The autonomic PNS nerves have two (2) motor outputs: the Sympathetic efferent motor output that
controls body tissues usually associated with physical activity or stress (Fight or Flight), and the Parasympathetic efferent motor output that
controls body tissues usually associated with the body in a less active state (Rest and Digest).
PNs: Periphery
-
unidirectional : -body cvs
to
(afferent
-
CNs to efferent
body
-
Somatic
=
Voluntary
-
Autonomic = involuntary
-
Sympathetic : fight or flight
-
Parasympathetic = rest and disest
1
, NEUROGLIAL CONNECTIVE TISSUE
Neuroglial (glial) connective tissue occupies about 60% of the nervous tissue and surrounds the neurons as a structural and functional support
system. Since it is a connective tissue, it contains a variety of specialized cells: Astrocytes, Microglial, Ependymal, Satellite, Oligodendrocyte,
-
nervous tissue : nerions
and Schwann.
ASTROCYTES MICROGLIAL EPENDYMAL SATELLITE
-
Neurostical : Support and structure
-
astrocytes -
Star shared -
hold nevrons in
place
These cells are very flat and surround
the cell body or soma of neurons within
PNS Ganglion. (A ganglion is a mass of
-
support Myelin Sheath on nevrons
These are the immune-phagocytic Ependymal cells are ciliated cells cell bodies surrounded with connective
These are star-shaped cells with multiple
amoeboid-like cells within the that line the central canal of the tissue. Ganglion act as connecting
processes. Protoplasmic astrocytes are
CNS. There main function is spinal cord and line the ventricles terminals in both the CNS and PNS.
associated with unmyelinated gray neurons
immunological; however, they may in the brain. Their main function is Satellite cells help protect the PNS
while Fibrous astrocytes are associated with
play a role in protecting the CNS to produce and circulate CSF. neuron cell body and regulate the
white myelinated neurons. Astrocytes are
form Tau and amyloid protein as exchange of material between the cell
tissues connecting cells to connect neurons -
central canal of
well. body and the surrounding ECM. They
and other body tissues to neurons. Astrocytes
may have receptors on their cell surface
are involved in releasing multiple -
immune system Spinal cora and
for virus and may be involved in
neurotransmitters and control substances that
are involved in synapse interactions, re-
function living ventricles harboring virus.
myelination of damaged white neurons,
- peripheral
initiation and control of immune responses,
-
phagocytes contain cilia to
isolation and
-
-
provide
and control and modulation of several types of Produce and more
neurotransmitter interactions at the synapse. Protection
CSf
THE NEUROGLIAL CELLS THAT FORM MYLEINATION AROUND AXONS- “THE WHITE MATTER”
OLIGODENDROCYTE - CNS SCHWANN - PNS ~
Wrap around axons full of fattytissue
,
-
allows ups so
to faster
-
oligodendrocytes = Cs
Oligodendrocytes look a lot like astrocytes but - Myelin : PNS
have less processes and are significantly
smaller. The processes of these cells attach
themselves to CNS neurons in the axon region
of the CNS neuron where they form a very thin The Schwann cell surround axons in the PNS. Unlike the oligodendrocyte in the CNS in
membrane around the axon. The membrane which its processes form a thin membrane around a large segment of the axon, the
then secretes a thin single layer of a white schwann enwraps itself like a jelly roll forming a thin multiple membrane
insulating material called myelin. wrapping which will then secrete the “White” myelin covering. The outer
This creates an electrically insulated “white membrane of the schwann cell with the nucleus forms a small bulge in the
Myelinated Sheath”, one layer thick around wrapping called the Neurolemma. The neurolemma aids the neuron in regenerating
the axon of the CNS neuron. These CNS the transmission pathway when neurons are damaged due to injury or disease.
neurons become know as “White”,
“myelinated” , or “White matter” Any
Neuron in the CNS that does not have a
myelin sheath is called “Gray”,
“unmyelinated “, or “Gray matter”
The Nodes of Ranvier
The Nodes of Ranvier are found only in
WHITE AXONS where they form gaps
-
Aps Jump from Mode torode between Myerin
between the CNS Oligodendrocyte
membranes and the PNS Schwann
cell membranes. These gaps expose -
Sulfatory conduction : wicker because of Jumps
the bare axon membranes.
The nodes are important because they
represent the regions where the ionic
conductance of the action potential
spreads.
The action potential transmission wave
appears to hop node to node in a fashion
called Saltatory Transmission
or Saltatory Conduction.
White Axons in both CNS and PNS are
often classified as “A” or “B” type axons
because they have very fast Saltatory
transmission speeds
2
, Nerve Connective Tissue
There are approximately 100-300 billion NEURONS in the nervous system. These nerve cells form an intricate neural network. Neurons are
-
transmission moves into around body
involved in a process called TRANSMISSION. They undergo an ionic disturbance called an action potential and secrete a neurotransmitter
that allows the next neuron in the connected network to either also have an action potential or inhibit the neuron from having an action potential.
Besides the neuron releasing neurotransmitter during an action potential, it also will undergo significant changes in the ICM (intracellular matrix)
biochemistry, and possibly physical changes that alter its circuit connections.
-
unipolar : one direction
STRUCTURAL VARIATIONS OF NEURONS
GRAY CNS/PNS MULTI-POLAR NEURON WHITE MYELINATED CNS MULTI-POLAR NEURON WHITE MYLEINATED PNS MULTI-POLAR NEURON
-
Bipolar= Cell body in Center branches into two
,
Soma
hilock -
Multipolor= Multiple dendrites can have axon branch several times
BI-POLAR AND UNI-POLAR (Often found in Sensory organs and receptors)
uni Bi-polar
Oligodendrocyte axun
Schwann Cell
Axon terminals
A typical Neuron has 5 parts to it: DENDRITES, SOMA, HILLOCK, AXON, and TELODENDRIA.
1) DENDRITES:
Numerous thin, short, branching processes off the cell body. They contain in their membrane receptors for - receptors for chemical messages (Neurotransmitters)
neurotransmitter molecules thus acting as a signal input. Their terminal end is referred to as a dendritic Knob.
Many dendrites are arranged so that their sodium ligand channels are deactivated as you move away from the
soma. This “decrement of electronic conduction” leads to a higher probability of greater excitory or inhibitory
effect by synapses located near the soma.
-
bind to ligand Nat Channels
-
Not flows into cell making inside
2) SOMA OR CELL BODY: -
flips charge
This is the typical eukaryotic cell region. The soma contains in its membrane receptors for neurotransmitter molecules thus
like the dendrites it is acting as a signal input.
The soma has an extensive network of rough and smooth endoplasmic reticulum called NISSL bodies. It also has a
well-developed Golgi apparatus. The soma is extremely active in producing NEUROTRANSMITTER and packaging the
neurotransmitter into vesicles. These neurotransmitter vesicles are then placed into special microtubules that
-
some= a lot of Mitochondria for ATP
extend all the way to the end of the telodendria called NEUROFIBRILS.
As the neural soma ages, it accumulates a fatty deposit within the cytosol of the soma called LIPOFUSCIN. Lipofuscin,
may over time interfere with neuron function.
vessicles made by Smooth FR
-
3) AXON HILLOCK:
> walked down axons to terminal
The axon hillock represents the tapered end of the soma. Like the dendrites and the main portion of the soma it contains in
its membrane receptors for neurotransmitter molecules thus also acting as a signal input. However, the number of
receptors for neurotransmitter in the hillock region is very little compared to the dendrite and soma membranes. -
hilock-axun body to axon is sensory
,
4) AXON:
The usually single axon propagates nerve impulses towards another neuron, a muscle
fiber, or a gland cell. The axon may be a bare, unmyelinated membrane process (GRAY)
or a covered myelinated membrane process (WHITE). The axon terminates into as many -
Axon = Voltage lates Channels
as 10,000 very thin hair-like processes called TELODENDRIA or axon terminals or terminal
boutons.
5) TELODENDRIA:
Very thin hair-like processes that form a connection between neurons called a SYNAPSE.
A synapse or synaptic cleft is an ultra microscopic (100 angstrom) space between 2
-
telondaria : Axon terminal
connecting cells. It is here, when the neuron has an action potential that the telodendria
terminal end called a telodendrial end bulb secretes neurotransmitter into the synaptic
cleft. The neurotransmitter then flows by diffusion over to the post-synaptic membrane of
the neuron, muscle cell or gland cell it is synapsed with. -
cat channels oped due to Voltage
The neurotransmitter is stored in vesicles within the telodendrial end bulb. Several
types of vesicles are found in the end bulb: EXCITOR vesicles, INHIBITOR vesicles,
DUAL (contain both Excitor and Inhibitor) vesicles. It has been observed as shown
below several release patterns: -
fuse to Vesicles to release nerrotransmitters
End-bulb has vesicles that contain both End-bulb has individual excitor vesicles and Two different end-bulbs- one releasing
Single release of either an excitor
excitor and inhibitor within them. Dual individual inhibitor vesicles. Dual release of excitor; the other releasing inhibitor
or an inhibitor
release of excitor and inhibitor excitor and Inhibitor from each vesicle
exocytosis -
nucleus determines What Neurotransmitter is released
-
inhibitory or excitatory nevron
3
