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The Nervous System

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The Neuron

Why does it look this?

Retrieval Practice:�Describe the function of each part of a neuron. Explain how its structure relates to its function

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Glial Cells and Synapses

Retrieval Practice:�Explain why neurons need glial cells.

What are synapses and why are they important?

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Pre and Post Synaptic Neurons

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Retrieval Practice:��What is the role of ions and ion channels in the transmission of information in the nervous system?

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Synapse and Neurotransmitters

Retrieval Practice:

Explain the concept of the “all-or-none” response of neurons

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Synapse and Neurotransmitters

Retrieval Practice:Explain excitatory vs inhibitory neurotransmitters.

How are synapses reset?

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Neurotransmitters

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The Nerves

Retrieval Practice:�How are nerves and neurons similar and different?

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Anatomy of a Nerve

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Signal Pathways

sensory neuron

(afferent)

interneuron(s)

Motor neuron

(efferent)

Peripheral Nervous System�(PNS)

Central Nervous System

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Reflex Arc

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Reflex Arc

Retrieval Practice:��How is a reflex arc similar and different from cognitive thinking?

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How do neurons send electrical signals

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Action Potential:�an “all or none” signal

The slides that follow will explain this process in detail.

Learn WHY each step occurs��Learn what happens to ions and ion channels at each step

Learn the voltage of resting potential, threshold potential and action potential (in mV)

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Resting Potential

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Resting Potential

- 70 mV

Inside the axon

Outside the axon

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Resting Potential

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

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Resting Potential

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

- 70 mV

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Action Potential

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

+ 40 mV

Stimulus

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Repolarization

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

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Repolarized / Overshoot

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

How can we return to resting potential?

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Repolarized / Overshoot

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Resting Potential

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

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Sodium Potassium Pump

K+

K+

K+

P

P

P

K+

K+

K+

Na+

Na+

Na+

Na+

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Na+

Na+

Na+

P

P

P

K+

K+

K+

K+

K+

K+

Na+

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P

K+

K+

K+

K+

K+

K+

Na+

Na+

Na+

Na+

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P

K+

K+

K+

K+

Na+

Na+

Na+

Na+

K+

K+

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Sodium Potassium Pump

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Repolarized / Overshoot

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Resting Potential

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

K+

Na+

Na+

K+

Na+

Na+

Na+

ATP

K+

K+

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Retrieval Practice:Describe what is happening at each numbered step.��Be clear about the state of ion channels, the movement of ions, and the potential difference.��WHY is each step occurring?

Why is resting potential always -70mV?

Why is action potential always +40mV?

How is threshold potential related to the �“all-or-none” response?

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Retrieval Practice:

Why is signaling in the nervous system an energy intensive process?

(i.e. at what stage(s) of this process is ATP being used?)

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Wave of Depolarization

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Myelination

Retrieval Practice:How does myelination increase the speed of signal transduction?

Which neurons are myelinated and which are not? Why?

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Retrieval Practice:How do synapses affect the speed of signal transduction in the nervous system?

How do synapses affect the complexity of information processing in the nervous system?

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Retrieval Practice:

When and why are these autonomic pathways stimulated?

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Complex Neural Networks

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The Human Connectome Project

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Neuron Networks in Fruit Fly Brain

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The Brain

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The Brain: The Cerebrum

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The Brain

Sensory Homunculus

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The Brain

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The Brain

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The Brain: Internal Anatomy

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Brain Evolution

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Brain Evolution

you are here

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Cerebral Surface Area

Size

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+ Anthropology

+ Sociology

+ Psychology

Biology

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