University Of Washington Synapses and Neuronal Signaling Discussion Questions

Please complete the following reading questions over p. 885-887; 895-898 in Chapter 45 of the Freeman text (see attachment)

Question1:

From the following choices (A-D), select which 2 factors best determine the membrane potential of a neuron?

A.) concentration gradient across the membrane

B.) charge gradient across the membrane

C.) the threshold potential of the membrane

D.) the surface area of a neuronal membrane

Question 2:

In a single neuron, what is the typical direction of signals?

A. axon to dendrite to cell body

B. dendrite to cell body to axon

C. axon to cell body to dendrite

Question 3:

For an action potential to occur, the membrane potential of a neuron must become

A. more positive

B. more negative

until it reaches the

A. resting membrane potential

B. threshold potential

C. repolarization phase

D. hyperpolarization phase

Question 4:

For an action potential to fire, the sum total of EPSPs must outnumber the sum total of IPSPs that occur at nearly the same time on a postsynaptic neuron.

True

False

Question 5: (explain)

In the 1920’s, the scientist, Otto Loewi, used heart muscle and a vagus nerve to show that indirect electrical signals are transmitted between cells who’s cytoplasm are not connected. Describe his experiment and explain his results.