04:15Refractory Period and Nerve Transmission: Anatomy and PhysiologyDr. Frank O'Neill GrowGrayMatter447views2rank
Multiple ChoiceCasey is taking a new medication that blocks potassium channels. What stage of an action potential would be MOST affected by this drug? 590views15rank
Multiple ChoiceWhen an action potential is at its peak, the electrical gradient forces potassium ____________.553views8rank
Multiple ChoiceWhich of the following electrical events occurs when a certain threshold is reached?905views1rank
Multiple ChoiceAn action potential is a phenomenon that either happens completely or doesn't happen at all.1274views1rank
Multiple ChoiceWhich part of the action potential occurs when the voltage-gated Na+ channels are inactivating and voltage-gated K+ channels open?909views1rank
Multiple ChoiceThe CNS can discriminate between strong and weak stimuli as strong stimuli __________.932views1rank
Multiple ChoiceDuring which phase of an action potential are voltage-gated K+ channels open, while voltage-gated Na+ channels are closed?1285views
Textbook QuestionThe anatomical region of a multipolar neuron where the AP is initiated is the a. soma, b. dendrites, c. axon's initial segment, d. axon terminals.401views1rank
Textbook QuestionWhat is the polarized membrane state? How is it maintained? (Note the relative roles of both passive and active mechanisms.)329views1rank
Textbook QuestionDescribe the events that must occur to generate an AP. Relate the sequence of changes in permeability to changes in the ion channels, and explain why the AP is an all-or-none phenomenon.349views1rank
Textbook QuestionWhen admitted to the emergency room, Sean was holding his right hand, which had a deep puncture hole in its palm. He explained that he had fallen on a nail while exploring a barn. Sean was given an antitetanus shot to prevent neural complications. Tetanus bacteria fester in deep, dark wounds, but how do their toxins travel in neural tissue?366views1rank
Textbook QuestionRochelle developed multiple sclerosis when she was 27. After eight years she had lost a good portion of her ability to control her skeletal muscles. How did this happen?318views1rank
Textbook QuestionMark the following statements as true or false. If a statement is false, correct it to make a true statement.c. The Na+/K+ pumps and gated channels maintain the Na+ and K+ gradients necessary for action potentials to occur.154views
Textbook QuestionThe drug neostigmine blocks the actions of acetylcholinesterase in the synaptic cleft. What effect would this have on synaptic transmission? What effects might you expect to see as a result of this drug?172views
Textbook QuestionDuring a surgical procedure, an anesthesiologist administers to the patient an inhaled anesthetic agent that opens Cl− channels in the postsynaptic membranes of neurons in the brain. Explain why this would put the patient 'to sleep' for the duration of the surgical procedure.182views
Textbook QuestionAlbert accidentally ingests the poison tetrodotoxin from the pufferfish, which you know blocks voltage-gated Na+ channels. Predict the symptoms Albert will experience from this poisoning.157views
Textbook QuestionAlbert, the patient in question 3, takes the drug lithium, which reduces the permeability of the neuronal axolemma to Na+ (that is, it allows fewer Na+ to enter the axon). Predict the effect this would normally have on his neuronal action potentials. Do you think this drug would be beneficial or harmful, considering his condition?158views
Textbook QuestionPredict the effect that tetrodotoxin would have on Albert's muscle fiber action potentials (see question 3). Would it affect end-plate potentials at the motor end plate? Why or why not? (Connects to Chapter 10)162views
Textbook QuestionExplain what would happen if depolarization of the trigger zone led to a negative feedback loop instead of a positive one. (Connects to Chapter 1)145views
Textbook QuestionHarry has a kidney condition that causes changes in his body's electrolyte levels (concentration of ions in the extracellular fluid). As a result, he is exhibiting tachycardia, an abnormally fast heart rate. Which ion is involved, and how does a change in its concentration cause Harry's symptoms?89views
Textbook QuestionIn the CNS, a neuron typically receives information from other neurons at its (a) axon, (b) Nissl bodies, (c) dendrites, (d) nucleus.87views