Chapter 2 Quiz

Which of the following is NOT true for sodium ions when the cell is at resting potential?

Sodium tends to be driven out of the neuron by the electrical gradient.

Glucose enters the brain via which type of transport?

active transport

Multiple sclerosis is one of several:

demyelinating diseases

Allowing only certain people to cross the street, and only at certain times, is comparable to a neuron's ____ with respect to ions.

selective permeability

Which of the following molecules would be able to passively cross the blood-brain barrier?

small, uncharged molecules

The surface of a dendrite is lined with specialized junctions through which the dendrite receives information from other neurons. What are these junctions called?

synaptic receptors

Ribosomes are the part of a cell that:

synthesizes new proteins.

Which of the following contributed most to Cajal's ability to find that neurons are separate from one another?

Camillo Golgi's cell staining method

What is the result if a stimulus shifts the potential inside a neuron from the resting potential to a potential slightly closer to zero?

Depolarization

Additional stimulation beyond the threshold of excitation will result in a greater depolarization of the membrane during an action potential.

FALSE

The sodium-potassium pump is what normally brings the membrane back to its original state of polarization after the peak of the action potential.

FALSE

What is the main source of nutrition for vertebrate neurons?

Glucose

A prolonged increase in the permeability of the membrane to sodium ions would interfere with a neuron's ability to have an action potential.

TRUE

Which of these is true of glial cells?

They do not transmit information over long distances.

At what point do the sodium gates begin to close, shutting out further entry of sodium into the cell?

at the peak of the action potential

When a neuron's membrane is at rest, the concentration gradient tends to move sodium ____ the cell and the electrical gradient tends to move it ____ the cell.

into, into

The resting potential is mainly the result of:

negatively charged proteins inside the cell.

The presence of an all-or-none law suggests that neurons can only convey different messages by changing their:

rate or pattern of action potentials.

The concentration gradient refers to:

the difference in distribution for various ions between the inside and outside of the membrane.

What will NOT affect the speed of an action potential?

the length of the axon