Event "D" in the diagram above is referred to as... O a Polarization O b. Depolarization Oc. Refractory period d. Repolarization Use the following information to answer the next question Membrane potential (mv) -55 Action potential of a neuron in response to a stimulus of -55 mV D A B Time

A A Aa v Ao O... 11 AaBbCcDdEe AaBbCcDc AaBbCcDdE AaBb( AaBbCcDdEE AaBbCcDdEe U v ab A ev A v X, Normal No Spacing Heading 1 Heading 2 Title Subtitle temporal summation spatial summation Unidirectional and non-degrading Action potential o Depolarization; Na gates opening o Repolarization: K gates opening o Hyperpolarization: K gates closing Movement down an axon Refractory periods Myelin and Axon size effect Action potential stimulated release Neurotransmitter (NT) recycling Neurotransmitters o Acetylcholine Biological amines (Serotonin, norepinephrine and epinephrine) Single amino acids (Glutamate and GABA) Fast and Slow effects and Receptor effects The Autonomic System Division definition

What effect would a WEAKER stimulus have on C?  a. Greater amplitude (height) b. Lower amplitude c. Narrower curve d. No change e. Wider curve

1. The graph above represent time in milliseconds.  At what time (in milliseconds) is the inside of the neuron the most positive and why? 2. Explain why the membrane potential changes at X 3. Explain what is happening at point C to the sodium and potassium ions and how this is affecting the membrane potential 4. Describe two things that contribute to the resting membrane potential

Under what conditions could the opening of a chloride channel actually depolarize a neuron rather than hyperpolarize it? i. The neuron is resting at -75 mVii. The extracellular chloride concentration is lower than the intracellular chloride concentrationiii. The neuron is close to its threshold of -55 mVa. i onlyb. iii onlyc. i and ii onlyd. ii and iii onlye. i, ii, and iiif. None of these

Which statement is true regarding chemical neurotransmission? O An IPSP closer to the soma will diminish the effects of an EPSP on a dendrite Chemical neurotransmission is mediated by gap junctions All neurotransmitter receptors are located on the postsynaptic cell membrane Neurotransmitters remain in the synaptic cleft indefinitely

7. Anodal Break excitation. Starting with the default parameter values, set "Sweep Duration" to 10 msec. Now decrease the "Stimulus 1 Amplitude” until it reaches-225 μA. An action potential is evoked by the hyperpolarizing stimulus! This phenomenon is called anode break excitation. Can you explain why a hyperpolarizing stimulus evokes an action potential? 8. Spreading Depression. Starting with the default parameter values, set "Stimulus 1 Amplitude" to 0 and "Sweep Duration" to 20 ms. Now slowly raise the "K+ equilibrium potential" to more and more positive values. As the K+ equilibrium potential is raised, you will observe the following sequence of events. The membrane potential depolarizes. Spontaneous action potentials are generated. The frequency of the action potentials increases. The amplitude of the action potentials diminishes. The action potentials die out as the membrane potential continues to depolarize. The same sequence of events occurs during spreading depression episodes…

Expression of which of the following lowers the threshold for firing action potentials? O A. Voltage-dependent K* channels OB. Na+, K+-ATPase OC. GABAA receptors OD. CI channels O E. Voltage-dependent Na* channels

This a anatomy question

- The velocity of action potential is high in: a- Myelinated-small diameter neuron b- Unmyelinated-small diameter neuron diameter neuron c- Unmyelinated-wide d- None of the above