Catalyst You are at a Wild game and Nordy launches a t- shirt at your head. You blink just as the shirt/projectile gets close but catch it anyways! Explain what happened on a neurological level. 1

Today! Neurons & Action Potential Complete Lab 2

Fig Generating words Max Speaking words Hearing words Seeing words Min

Fig Presynaptic cell

Fig Stimulus Presynaptic cell

Fig Dendrites Stimulus Presynaptic cell

Fig Dendrites Stimulus Nucleus Presynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Presynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell Axon

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell Axon Postsynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell Axon Synaptic terminals Postsynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell Axon Synaptic terminals Synapse Postsynaptic cell

Fig Dendrites Stimulus Nucleus Cell body Axon hillock Presynaptic cell Axon Synaptic terminals Synapse Postsynaptic cell Neurotransmitter

Fig. 48-5a Dendrites Axon Cell body Sensory neuron

Fig. 48-5b Interneurons Portion of axon Cell bodies of overlapping neurons 80 µm

Fig. 48-5d Motor neuron

Sensory Neuron Investigation… Progress so far? Complete it! Lab due Thursday Friday

Fig. 48-6b (b) OUTSIDE CELL Na + Key K+K+ Sodium- potassium pump Potassium channel Sodium channel INSIDE CELL

Fig. 48-9c Strong depolarizing stimulus +50 Membrane potential (mV) –50Threshold Resting potential – Time (msec) (c) Action potential Action potential 6

Fig Key Na + K+K+ +50 Action potential Threshold –50 Resting potential Membrane potential (mV) –100 Time Extracellular fluid Plasma membrane Cytosol Inactivation loop Resting state Sodium channel Potassium channel Depolarization 2 3 1

Fig Key Na + K+K+ +50 Action potential Threshold –50 Resting potential Membrane potential (mV) –100 Time Extracellular fluid Plasma membrane Cytosol Inactivation loop Resting state Sodium channel Potassium channel Depolarization

Fig Key Na + K+K+ +50 Action potential Threshold –50 Resting potential Membrane potential (mV) –100 Time Extracellular fluid Plasma membrane Cytosol Inactivation loop Resting state Sodium channel Potassium channel Depolarization Rising phase of the action potential

Fig Key Na + K+K+ +50 Action potential Threshold –50 Resting potential Membrane potential (mV) –100 Time Extracellular fluid Plasma membrane Cytosol Inactivation loop Resting state Sodium channel Potassium channel Depolarization Rising phase of the action potential Falling phase of the action potential

Fig Key Na + K+K+ +50 Action potential Threshold –50 Resting potential Membrane potential (mV) –100 Time Extracellular fluid Plasma membrane Cytosol Inactivation loop Resting state Sodium channel Potassium channel Depolarization Rising phase of the action potential Falling phase of the action potential 5 Undershoot

Fig Axon Plasma membrane Cytosol Action potential Na +

Fig Axon Plasma membrane Cytosol Action potential Na + Action potential Na + K+K+ K+K+

Fig Axon Plasma membrane Cytosol Action potential Na + Action potential Na + K+K+ K+K+ Action potential K+K+ K+K+ Na +

Fig Axon Schwann cell Myelin sheath Nodes of Ranvier Node of Ranvier Schwann cell Nucleus of Schwann cell Layers of myelin Axon 0.1 µm

Fig Cell body Schwann cell Depolarized region (node of Ranvier) Myelin sheath Axon Saltatory conduction

Fig Voltage-gated Ca 2+ channel Ca Synaptic cleft Ligand-gated ion channels Postsynaptic membrane Presynaptic membrane Synaptic vesicles containing neurotransmitter 5 6 K+K+ Na +

Table 48-1