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A cell has a total membrane potential of -70 mV. Cation A is found in both the ECF and ICF and has an equilibrium potential of +45 mV. Cation B is found in both the ECF and ICF and has an equilibrium potential of -85 mV. True or false: Cation A has a higher concentration in the ICF than the ECF. (0.5 pts.)

True or false: The strength of an action potential depends on the number and type of graded potentials. (0.5 pts.)

Sequential EPSPs from a single presynaptic neuron will be most effective at bringing a postsynaptic neuron to threshold when ________.

True or false: An EPSP can be summed and has no refractory period.

Olympic athletes train in Colorado Springs, Colorado, because this location is at a high altitude near the 14,000-foot Pikes Peak. Which statement best describes why this location was chosen?

Which step of synaptic transmission at the neuromuscular junction is disrupted by botulinum toxin, a toxin released from Clostridium botulinum?

The blood-brain barrier is not effective against which of the following?

At which points on the diagram is the activation gate of the voltage-gated sodium channel open?

Take the following hypothetical cell: ICF concentrations are 35 mM KCl and 60 mM NaCl. ECF concentrations are 20 mMKCl and 100 mM NaCl. The membrane is 3.5 times more permeable to K+ than to Na+. What would the equilibrium potential for potassium be?

During which phase of the cardiac cycle are all four heart valves open?