Exam 4: Principles of Neural and Hormonal Communication

An action potential on a neuron develops when

Indicate whether an excitatory or inhibitory synapse is being described. a.excitatory synapse b.inhibitory synapse -Small depolarization of the postsynaptic neuron

At an excitatory synapse, an action potential in the presynaptic neuron increases

Use the answer code below to answer this section. a.increased PNa+ and no change in PK+ b.decreased PNa+ and decreased PK+ c.increased PK+ and no change in PNa+ d.increased PK+ and increased PNa+ e.increased PK+ and decreased PNa+ f.Na influx g.Na+ efflux h.K+ influx i.K+ efflux -Ion movement responsible for the falling phase of the action potential

Amplification is a phenomenon associated with hormones derived from cholesterol.

During the resting potential, the membrane is more permeable to potassium ions than to sodium ions.

The time following an action potential during which a membrane cannot respond to another stimulus, regardless of its strength, is called the relative refractory period.

The grand postsynaptic potential depends on the sum of activity of the presynaptic inputs.

The refractory period prevents action potentials from spreading back over the part of the membrane where the impulse has just passed.

During the rising phase of the action potential,

Which statement is incorrect?

Multiple sclerosis develops from a buildup of myelin of a neuron.

Presynaptic facilitation results from

Spatial summation occurs on a postsynaptic neuron would occur when

Opening either a chemically-gated Na⁺ channel or a chemically-gated K⁺ channel during the resting potential would cause

If neurotransmitter from Y causes the membrane potential of the postsynaptic cell to decrease slightly, then

At ____________________ potential, typically around -55 mv, rapid depolarization occurs.

A plasma membrane is polarized if it separates particles with an opposite ____________________.

Opening channels that allow ____________________ ions or ____________________ ions result in depolarization of the plasma membrane.

____________________-soluble hormones must use ____________________ systems to exert their effects on target cells.