Exam 48: Neurons, Synapses, and Signaling

Suppose a particular neurotransmitter causes an IPSP in postsynaptic cell X and an EPSP in postsynaptic cell Y. A likely explanation is that

Action potentials move along axons ________.

When two excitatory postsynaptic potentials (EPSPs)occur at a single synapse so rapidly in succession that the postsynaptic neuron's membrane potential has not returned to the resting potential before the second EPSP arrives, the EPSPs add together producing ________.

Which of the following will increase the speed of an action potential moving down an axon? I.Action potentials move faster in wider axons. II.Action potentials move faster in axons lacking potassium ion channels. III.Action potentials move faster in myelinated axons.

The three stages of information processing in animals include ________.

If you experimentally increase the concentration of Na⁺ outside a cell while maintaining other ion concentrations as they were, what would happen to the cell's membrane potential?

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium/potassium channel and opens it. This is an example of ________.

The concentrations of ions are very different inside and outside a nerve cell due to ________.

In a simple synapse, neurotransmitter chemicals are received by ________.

A common feature of action potentials is that they

The motor (somatic nervous)system can alter the activities of its targets, the skeletal muscle fibers, because ________.

What happens when a resting neuron's membrane depolarizes?

One-way synaptic transmission occurs because ________.

Why do Na⁺ ions enter the cell when voltage-gated Na⁺ channels are opened in neurons?

Refer to the following graph of an action potential to answer the question. At label ________, the cell is not hyperpolarized; however, repolarization is in progress, as the sodium channels are inactivated or becoming inactivated, and many potassium channels have opened.

Of those listed, which event occurs first following a depolarizing stimulus applied to the presynaptic membrane of an axon terminal?

The membrane potential in which there is no net movement of the ion across the membrane is called the ________.

A chemical that affects neuronal function but is not stored in presynaptic vesicles is ________.

What happens if twice as many inhibitory postsynaptic potentials (IPSPs)as excitatory postsynaptic potentials (EPSPs)arrive in close proximity at a postsynaptic neuron?

What would probably happen if a long neuron had one continuous myelin sheath down the length of the axon with no nodes of Ranvier?