Which of the following statements does NOT correctly describe the repolarization of a neuron? a. The potassium channels are slower to open, allowing the potassium ions to leave after depolarization. b. The potassium ions leave the cell, thereby returning the neuron to its resting potential. c. The neuron becomes more polarized and more negatively charged than its original resting membrane potential. d. The sodium and potassium channels open, allowing the positive ions to move out of the cell.

When an action potential arrives in an axon terminal, synaptic vesicles containing acetylcholine are released by: a. facilitated diffusion. b. osmosis. c. exocytosis. d. endocytosis.

Which of the following situations correctly illustrates the all-or-none principle? Select one: o a. A smaller voltage change will result in a smaller nerve impulse. o b. A stronger impulse can be generated by increasing the number of open voltage-gated sodium channels during depolarization. O C. A greater voltage change and a smaller voltage change will result in the same action potential as long as the threshold potential has been reached. o d. A faster impulse can be generated with a voltage change that is greater than the threshold potential.

A channel opens on a postsynaptic membrane that causes a negative ion to leave the cell. What type of graded potential is this? a. depolarizing b. repolarizing c. hyperpolarizing d. non-polarizing

Which of the following statements relating to depolarization is incorrect? a. it is a reduction in membrane potential  b. inside the membrane becomes less negative than resting potential c. enhances the probability of producing an action potential d. causes the voltage of internal membrane towards zero e. none of the above

When summation of multiple graded synaptic potentials occurs which of the following would "neutralize/cancel out" an EPSP in dendrites? A. opening a voltage gated sodium channel B. opening a voltage gated calcium channel  C. openning a ligand gated calcium channel D. closing a ligand gated potassium channel E. opening a ligand gated chloride channel

A hyperpolarized cell can be generated when:   Group of answer choices A. ligand-gated ionotropic channels for Cl- open B. voltage-gated Cl- channels in the postsynaptic membrane open C. Na + flows into the cell down its concentration gradient D. an action potential is generated in the postsynaptic membrane.

The morphological difference between bipolar neurons and unipolar neurons is_ and that determines how they are classified. a. the type of neurotransmitter they contain b. one is a Golgi Type I and the other is a Golgi Type II c. the number of axons that they have d. the number of different types of neurotransmitters they contain e. none of the above

Which of the following statements is FALSE? a. graded potentials can sum over time and space, action potential cannot b. action potentials have refractory periods, graded potentials do not c. action potentials are all-or-none, graded potentials are not d. graded potentials and action potentials are caused by ions moving through open channels e. all of the above statements are true (if all of the above are true this is the correct answer) ....

There is a type of toxin found in the liver of the puffer fish that prevents the opening of voltage-gated Na+ channels in neurons. The effect of this toxin is to: Group of answer choices A. prevents the initiation of the action potential B. depolarizes the membrane potential and maintains it depolarized C. prolongs the return of the membrane potential to the resting level D. increases the duration of the action potential