THE NERVOUS SYSTEMHow do neurons communicate?

THE ROAD TO CEPHALIZATION…

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1. Which letter represents the dendrite of the sensory neuron?

2. What type of cell is found only in the central nervous system?

3. What structure conducts nerve impulses from the spinal cord to the gall bladder?

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1. Which letter represents the dendrite of the sensory neuron?W

2. What type of cell is found only in the central nervous system? Interneuron

3. What structure conducts nerve impulses from the spinal cord to the gall bladder? Motor Neuron

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What event occurs during repolarization? A. the sodium gates openB. the potassium gates openC. the net movement of sodium ions into the

axonD. the net movement of potassium ions into

the axon

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What event occurs during repolarization? A. the sodium gates openB. the potassium gates openC. the net movement of sodium ions into the

axonD. the net movement of potassium ions into

the axon

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Which of the following occurs between time X and time Y?

A. repolarizationB. depolarizationC. resting potentialD. refractory period

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Which of the following occurs between time X and time Y?

A. repolarizationB. depolarizationC. resting potentialD. refractory period

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What event occurs during depolarization?

A. the sodium gates closeB. the potassium gates openC. the net movement of sodium ions into the axonD. the net movement of potassium ions into the axon

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What event occurs during depolarization?

A. the sodium gates closeB. the potassium gates openC. the net movement of sodium ions into the

axonD. the net movement of potassium ions into the axon

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Tell the story of how information travels from your spinal cord to the muscles of your arm to make them move. Include the following terms: Resting potential Action potential

Depolarization Repolarization

Refractory Period Propagation

TRY THIS! Compare resting potential and action

potential

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potential

PROPAGATION OF THE NERVE IMPULSE

Where in the myelinated axon would an action potential actually occur?

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Where in the myelinated axon would an action potential actually occur?

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How does a neuron respond to a strong stimulus?A. It produces a larger action potentialB. It causes more ions to move across the

neuron membraneC. It causes more action potentials in a

given period of timeD. It causes action potentials to be

conducted at a faster speed

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How does a neuron respond to a strong stimulus?A. It produces a larger action potentialB. It causes more ions to move across the

neuron membraneC. It causes more action potentials in a

given period of timeD. It causes action potentials to be

conducted at a faster speed

TRANSMISSION ACROSS THE SYNAPSE

Animation

TRANSMISSION ACROSS THE SYNAPSE

Nerve impulse reaches the axon bulb

Ca2+ ions move into the axon bulb.

Ca2+ ions interact with contractile proteins and pull the vesicles containing neurotransmitters to the surface of the presynaptic membrane.

The vesicles merge with the presynaptic membrane and release neurotransmitters into the synaptic cleft by exocytosis.

TRANSMISSION ACROSS THE SYNAPSE

The neurotransmitters diffuse across the cleft.

The neurotransmitters bind with specific receptors on the postsynaptic membrane.

Depolarization occurs on the postsynaptic membrane if threshold is reached.

The neurotransmitter is destroyed by an enzyme (ex. acetylcholinesterase) or reabsorbed back into the presynaptic membrane.

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Which of the following describes the role of calcium ions during synaptic transmission?

A. They cause Y to become inactivated.B. They act as carriers to move Y toward Z.C. They cause Y to undergo endocytosis at W.D. They initiate the process that results in X moving toward W.

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Which of the following describes the role of calcium ions during synaptic transmission?

A. They cause Y to become inactivated.B. They act as carriers to move Y toward Z.C. They cause Y to undergo endocytosis at W.D. They initiate the process that results in X moving toward W.

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Tell the story of how information travels from your spinal cord to the muscles of your arm to make them move. Include the following processes: Resting potential Action potential

Depolarization Repolarization

Refractory Period Propagation Transmission

across the Synapse