34 questions
Stimulation of the sympathetic nervous system most frequently results in which of the following?
Acceleration of heart and breathing rates and dilation of pupils
Stimulation of tearing, salivation, and peristalsis
Calming of the body
Construction of the muscles of the hands and feet
Raising the perceptual threshold of olfactory and gustatory receptors
Acetylcholine, a common neurotransmitter, is synthesized in the pre-synaptic end of a neuron and released into the synaptic cleft as shown in the illustration above. What would be a likely result of an increase in the amount of acetylcholinesterase present in the synaptic cleft?
More sodium would enter the sodium/potassium ion channels of the postsynaptic dendrite
More potassium would enter sodium/potassium ion channels of the postsynaptic dendrite
Fewer sodium/potassium ion channels would be opened in the postsynaptic dendrite
Fewer vesicles in the pre-synaptic axon terminal would contain acetylcholine
Lidocaine is a local anesthetic that works as a temporary pain reliever. Lidocaine works by binding to voltage sensitive Na+ gates on pain receptors and prevents the gates from opening. Which of the following best describes why Lidocaine is an effective anesthetic?
Lidocaine limits sodium influx, which increases the production of presynaptic vesicles.
Lidocaine increases sodium influx, which stimulates the propagation of the action potential.
Lidocaine decreases sodium influx, which decreases the propagation of the action potential.
Lidocaine increases sodium influx, which decreases the release of neurotransmitters.
The diagram below graphs an action potential. Use the Roman Numerals to indicate your answer to the following questions.
A neuron that is not conducting an action potential would have a membrane potential that is most like the value at
I and II
I and III
I and IV
II and III
The diagram below graphs an action potential. Use the Roman Numerals to indicate your answer to the following questions.
Open sodium channels allow positively charged sodium ions to enter the neuron. Which Roman Numeral on the graph indicates the time during which the sodium channels are open?
I
II
III
IV