Transcript Document
Axon
Terminal
Fine ending/swelling of the axon
Close to next dendrite
Inside contains neurotransmitters that are
contained inside a synaptic vesicle
Synaptic
Cleft
Space between dendrite and axon terminal
No action potential (nerve impulse) can be
carried out here so communication is done
through chemical synapse
Presynaptic membrane
Post synaptic membrane
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axon
terminal
synaptic vesicles
enclose neurotransmitters
synaptic cleft
During
an action potential the impulse travel
along the axon until it reaches the axon
terminal
Here gated Ca+ channels open up and Ca+
enters the axon terminal
Synaptic vesicles merge with presynaptic
membrane and bind with a specific protein
receptors
Depending
on the type of neurotransmitter
and receptor the response of the
postsynaptic neuron
Excitation
Action potential occurs
Inhibition
Action potential does not occur
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neurotransmitter
presynaptic
membrane
postsynaptic
membrane
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neurotransmitter
receptor
Na+
postsynaptic
neuron
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
axon
terminal
Ca2+
1. After an
action
potential
arrives at an
axon terminal,
Ca2+ enters,
and synaptic
vesicles fuse
with the
presynaptic
membrane.
synaptic vesicles
enclose neurotransmitters
synaptic cleft
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2. Neurotransmitters
are released
and bind to
receptors
on the
postsynaptic
membrane.
axon
terminal
Ca2+
1. After an
action
potential
arrives at an
axon terminal,
Ca2+ enters,
and synaptic
vesicles fuse
with the
presynaptic
membrane.
synaptic vesicles
enclose neurotransmitters
synaptic cleft
neurotransmitter
presynaptic
membrane
postsynaptic
membrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2. Neurotransmitters
are released
and bind to
receptors
on the
postsynaptic
membrane.
axon
terminal
Ca2+
1. After an
action
potential
arrives at an
axon terminal,
Ca2+ enters,
and synaptic
vesicles fuse
with the
presynaptic
membrane.
synaptic vesicles
enclose neurotransmitters
neurotransmitter
postsynaptic
membrane
neurotransmitter
receptor
Na+
postsynaptic
neuron
synaptic cleft
presynaptic
membrane
3. When an
excitatory
neurotransmitter
binds to a
receptor,
Na+ diffuses
into the
postsynaptic
neuron, and
an action
potential
begins.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2. Neurotransmitters
are released
and bind to
receptors
on the
postsynaptic
membrane.
axon
terminal
cell body of
postsynaptic
neuron
Ca2+
1. After an
action
potential
arrives at an
axon terminal,
Ca2+ enters,
and synaptic
vesicles fuse
with the
presynaptic
membrane.
synaptic vesicles
enclose neurotransmitters
neurotransmitter
postsynaptic
membrane
neurotransmitter
receptor
Na+
postsynaptic
neuron
synaptic cleft
presynaptic
membrane
3. When an
excitatory
neurotransmitter
binds to a
receptor,
Na+ diffuses
into the
postsynaptic
neuron, and
an action
potential
begins.
https://www.youtube.com/watch?v=rWrnz-
CiM7A
When
neurotransmitter released into
synaptic cleft it initiates a response and then
is removed
Removal
of neurotransmitters prevents
continues stimulation (or inhibition) of nerve
impulse
2
types of neurotransmitters
Excitatory
Excitatory neurotransmitters are not necessarily
exciting – they are what stimulate the brain.
Inhibitory
Those that calm the brain and help create balance are
called inhibitory.
balance mood and are easily depleted when the
excitatory neurotransmitters are overactive.
Acetylcholine
excitatory neurotransmitter
triggers muscle contraction
In the central nervous system, it is involved in
wakefulness, attentiveness, anger, aggression,
sexuality, and thirst
Alzheimer’s
disease is associated with a lack
of acetylcholine in certain regions of the
brain
Dopamine
involved in controlling movement and posture
It also modulates mood
The
loss of dopamine in certain parts of the
brain causes the muscle rigidity typical of
Parkinson’s disease
GABA
(gamma-aminobutyric acid)
is an inhibitory neurotransmitter
GABA contributes to motor control, vision, and
many other cortical function
Regulates anxiety
https://www.youtube.com/watch?v=vkpz7xFTWJ
o
Norepinephrine
is important for attentiveness, emotions,
sleeping, dreaming, and learning
Norepinephrine is also released as a hormone
into the blood, where it causes blood vessels to
contract and heart rate to increase.
Serotonin
contributes to various functions, such as
regulating body temperature, sleep, mood,
appetite, and pain
Endorphins
produced during exercise,excitement, pain, love and they
resemble the opiates in their abilities to produce a feeling of
well-being.
The name “endorphin” comes from endo- and -orphin; intended
to mean "a morphine-like substance originating from within the
body.
Curare - poison made from frog skin
and causes paralysis by blocking
Ach receptors at the neuromuscular
junction.
Strychnine poisoning can be fatal to
humans and animals and can occur by
inhalation, swallowing or absorption
through eyes or mouth
Strychnine is a neurotoxin which acts as
an antagonist of acetylcholine receptors. It
primarily affects the motor nerves in the
spinal cord which control muscle
contraction. An impulse is triggered at one
end of a nerve by the binding of
neurotransmitters to the receptors.
Read about Strychnine Poisoning
The neurotransmitter seretonin is vital
in regulating many of our basic
functions. Serotonin is, among other
things, the feel good neurotransmitter
and helps to regulate body temp.
Our brain cells are constantly trying to
bring some amount of serotonin back
into the cells and out of the synapse
using serotonin reuptake
transporters.
Ecstasy essentially takes these upkeep
transporters and reverses their roles.
This causes a massive flood of
serotonin from the brain cells into the
synapse.
The most common cause of
Ecstasy-related death is
overheating
(hyperthermia). MDMA
interferes with the body's
ability to regulate its own
body temperature and to
see other warning signs
allowing the body to
overheat without
discomfort especially
when dancing for hours
in hot clubs.
●Zoloft is part of a class of drugs called selective
serotonin reuptake inhibitors, or
● SSRIs for short. SSRIs act on a specific chemical
within the brain known as serotonin. This is one of
several chemicals used to send messages from one
nerve cell to another.
Brain
and Spinal Cord make up the CNS
CNS controls many bodily functions
Breathing
Heart rate
Body temperature
Blood pressure
Emotions
Memory
Creativity
The
Spinal Cord
The spinal cord extends from the base of the
brain through a large opening in the skull and
into the vertebral canal.
Meninges
protective membrane that surrounds spinal cord
and brain
Cerberospinal
fluid
found between meninges and brain or spinal cord
Provides cushioning
The
spinal nerves project from the cord
between the vertebrae.
Fluid-filled intervertebral disks cushion and
separate the vertebrae.
A cross section of the spinal cord shows a
central canal, gray matter, and white matter.
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spinal cord
spinal nerve
vertebra
intervertebral
disk
a.
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dorsal
white matter
dorsal root
gray matter
dorsal root
ganglion
central canal
ventral root
spinal
nerve
meninges
b.
ventral
Provides
communication between the brain
and the peripheral nerves
Sends sensory information to brain
Realays motor impulses from brain to muscles
Center
for thousands of arc reflexes
Allow nerves and muscles to respond quickly to
dangerous stimuli
https://vimeo.com/93183048
https://www.youtube.com/watch?v=SgzRAAY
0wbA
https://www.youtube.com/watch?v=rJ02HW
_HDaE