Answer Happy

4. Which of the following is the correct temporal sequence for events at the neuromuscular junction? Release of Ach; action potential in the muscle end plate; action potential in the muscle O Release of Ach action potential in the motor nerve; action potential in the muscle Uptake of Ca2+ into the presynaptic terminal release of acetylcholine (ACh): depolarization of the muscle end plate Action potential in the motor nerve; depolarization of the muscle end plate; uptake of Ca2+ into the presynaptic nerve terminal O Uptake of Ca2+ into the motor end plate action potential in the motor end plate; action potential in the muscle
12. A 56-year-old woman with severe muscle weakness is hospitalized. The only abnormality in her laboratory values is an elevated serum K+ concentration. The elevated serum K+ causes muscle weakness because? ONa+ channels are opened by depolarization Na+ channels are unresponsive due to depolarization K+ channels are opened by Depolarization the resting membrane potential is hyperpolarized the K+ equilibrium potential is hyperpolarized
16. A newly developed local anesthetic blocks Na+ channels in nerves. Which of the following effects on the action potential would it be expected to produce? Shorten the absolute refractory period Abolish the hyperpolarizing afterpotential O Increase the K+ equilibrium potential O Decrease the Na+ equilibrium potential Abolish the upstroke of the action potential