Transcript The Nervous System

The Nervous
System
Homeostasis
What is it?
Homeostasis: the process of
keeping internal conditions
relatively constant.
The Nervous System
What does it do?
• Controls functions in the body
• responds to internal and
external stimuli.
The Nervous System
What does it do?
• maintains homeostasis
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The Nervous System
What is it?
Nervous system:
• Complex network
of specialized cells that transmit
messages in the body
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The Nervous System
Two halves
• CNS = Central Nervous System
• PNS = Peripheral Nervous System
The Nervous System
Two halves
• CNS = Central Nervous System
–Brain
–Spinal cord
The Nervous System
Two halves
• CNS = Central Nervous System
• PNS = Peripheral Nervous System
–Cranial nerves (nerves off brain)
–Spinal Nerves (off the spinal cord)
The BRAIN
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Parts of the Brain
• Cerebrum
–responsible for all voluntary activities
Parts of the Brain
• Cerebrum
–Two hemispheres
• Left and Right
hemispheres
• Right hemisphere
controls left side of
body, left controls
the right
Parts of the Brain
Parts of the Brain
• Cerebrum
–Four lobes
Frontal
lobe
Parietal
lobe
Temporal
lobe
Occipital
lobe
Parts of the Brain
• Cerebellum
–means “little
brain”
–controls
coordination
–Let’s see how
well your
cerebellum
works…..
Parts of the Brain
• Brainstem
– connects brain to
spinal cord
– Controls heart rate,
breathing, and
swallowing
– Also vomiting,
hiccupping, coughing
and sneezing
Parts of the Brain
• Parts of the
Brainstem
–Midbrain
–Pons
–Medulla
oblongatta
Parts of the Brain
Parts of the Brain
• Thalamus and Hypothalamus
Parts of the Brain
• Thalamus: receives messages from
the sense organs
• Hypothalamus: control center for
hunger, thirst, fatigue, anger and body
temp.
• So, the hypothalamus maintains what?
Parts of the Brain
The Nervous System
• CNS = Central Nervous System
–Brain
–Spinal cord
• PNS = Peripheral Nervous System
–Cranial nerves (nerves off brain)
–Spinal Nerves (off the spinal cord)
Spinal Cord
• Main communication link
between brain and rest of body
the vertebral column
• Protected by...
• 31 pairs of nerves branch off
• Reflex happens within the
spinal cord
Reflex
• When an impulse skips going to the brain and just
comes right back out the spinal cord
The Neuron
Start by labeling
a neuron
Neurons:
A nerve cell
2
3
4
Axon terminals
8
5
1
Node
6
Schwann’s
cells
7
The Nerve Impulse
Nerve Impulse:
flow of electrical charges along
the neuron
Starts at the dendrite, travels to cell body or soma, down the
axon and then the axon terminal. Then a neurotransmitter
will carry the impulse across the synapse
The Neuron
Electrical flow of the nerve impulse:
Dendrites Soma
Axon
Axon Terminals
The next slide shows
what it will look like
when you put several
neurons in a row (in
other words a nerve)
The Neuron
Three types of neurons…
1. Sensory neuron
– Sends impulse from sense organs toward
brain
2. Motor neuron
– Away from brain/spinal cord to
muscles/organs
3. Interneuron
– Connect sensory to motor neurons
– Found only in the spinal cord
Synapse
• Gap between one
neuron and the
next neuron
• Where the impulse
jumps to the next
neuron
Neurotransmitter:
Chemicals used to pass the impulse
Let’s label the picture:
Axon
terminal
Neurotransmitter
Axon
Synapse
Synapse
Soma
Transport
protein
Neurotransmitter
Neurotransmitters
One common neurotransmitter
is: ACETYLCHOLINE
Cranial nerves
• Cranial nerves: nerves that
branch directly off of the brain
–Most of them are sensory
–Others are motor
1. Olfactory:
2. Optic
3. Oculomotor
4. Troclear
5. Trigeminal
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic
3. Oculomotor
4. Troclear
5. Trigeminal
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor
4. Troclear
5. Trigeminal
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear: eye movement
5. Trigeminal
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear: eye movement
5. Trigeminal: feeling in face (3 branches)
6. Abducens:eye movement
7. Facial
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial: face movements, saliva, tear ducts
8. Auditory (vestibulocochlear)
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial: face movements, saliva, tear ducts
8. Auditory/vestibulocochlear: hearing, balance
9. Glossopharyngeal
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial: face movements, saliva, tear ducts
8. Auditory/vestibulocochlear: hearing, balance
9. Glossopharyngeal: taste back 1/3 of tongue
10.Vagus
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial: face movements, saliva, tear ducts
8. Auditory/vestibulocochlear: hearing, balance
9. Glossopharyngeal: taste back 1/3 of tongue
10.Vagus: control organs
11.Accessory
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear
5. Trigeminal: feeling in face (3 branches)
6. Abducens
7. Facial: face movements, saliva, tear ducts
8. Auditory/vestibulocochlear: hearing, balance
9. Glossopharyngeal: taste back 1/3 of tongue
10.Vagus: control organs
11.Accessory: muscles of neck and shoulders
12.Hypoglossal
1. Olfactory: smell
2. Optic: vision
(forwardNerves
and peripheral)
Cranial
3. Oculomotor: eye movement, constricts pupil
4. Troclear: eye movement
5. Trigeminal: feeling in face (3 branches)
6. Abducens: eye movement
7. Facial: face movements, saliva, tear ducts
8. Auditory/vestibulocochlear: hearing, balance
9. Glossopharyngeal: taste back 1/3 of tongue
10.Vagus: control organs
11.Accessory: muscles of neck and shoulders
12.Hypoglossal: tongue movements
The Nervous System
• Central Nervous System (CNS)
–Brain
–Spinal cord
• Peripheral Nervous System (PNS)
–Cranial nerves (nerves off brain)
–Spinal Nerves (off the spinal cord)
Spinal Nerves
• Nerves that branch off the
spinal cord
• ____ pair
• Travel to …
every part of the body
Cervical
Thoracic
Lumbar
Sacral
The Neuron
The Nervous System
• Central Nervous System (CNS)
–Brain
–Spinal cord
All made
of neurons
• Peripheral Nervous System (PNS)
–Cranial nerves (nerves off brain)
–Spinal Nerves (off the spinal cord)
Neurons:
A nerve cell
2
3
4
Axon terminals
8
5
1
Node
6
Schwann’s
cells
7
The Nerve Impulse
Nerve Impulse:
flow of electrical charges along
the neuron
The Neuron
Electrical flow of the nerve impulse:
Dendrites Soma
Axon
Axon Terminals
The Neuron
Three types of neurons…
1. Sensory neuron
– Sends impulse from sense organs toward
brain
2. Motor neuron
– Away from brain/spinal cord to
muscles/organs
3. Interneuron
– Connect sensory to motor neurons
– Found only in the spinal cord
Synapse
• Gap between one
neuron and the
next neuron
• Where the impulse
jumps to the next
neuron
Neurotransmitter:
Chemicals used to pass the impulse
Let’s label the picture:
Axon
terminal
Neurotransmitter
Axon
Synapse
Synapse
Soma
Transport
protein
Neurotransmitter
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