Chapter 48 Study Guide

Question 1

What type of neurons is responsible for the interpretation of sensory input?
A) sensory neurons
B) motor neurons
C) interneurons
D) peripheral neurons

Answer 1

interneurons

Question 2

A nerve is a collection of ________.
A) dendrites
B) nerve cell bodies
C) synapses
D) axons

Answer 2

axons

Question 3

Which of these ions is more abundant in the interior of a resting neuron than in the fluid surrounding the neuron?
A) Cl-
B) Ca++
C) Na+
D) K+

Answer 3

K+

Question 4

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?
A) The membrane potential would become more negative.
B) The membrane potential would become less negative.
C) The membrane potential would be unaffected.
D) The membrane potential would become positive.

Answer 4

The membrane potential would become less negative.

Question 5

The concentrations of sodium and potassium ions are very different inside and outside a neuron. What contributes to these differences?
A) osmosis
B) diffusion of chloride ions
C) sodium-potassium pumps
D) exocytosis and endocytosis

Answer 5

sodium-potassium pumps

Question 6

Action potentials move along axons ________.
A) more slowly in axons of large diameter than in axons of small diameter
B) by activating the sodium-potassium “pump” at each point along the axonal membrane
C) more rapidly in myelinated than in unmyelinated axons
D) by reversing the concentration gradients for sodium and potassium ions

Answer 6

more rapidly in myelinated than in unmyelinated axons

Question 7

The following are events in the transmission of a signal at a chemical synapse.
1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.
2. Calcium ions rush into neuron’s cytoplasm.
3. An action potential depolarizes the membrane of the presynaptic axon terminal.
4. The ligand-gated ion channels open.
5. The synaptic vesicles release neurotransmitter into the synaptic cleft.
Which sequence of events is correct?
A) 1 → 2 → 3 → 4 → 5
B) 2 → 3 → 5 → 4 → 1
C) 3 → 2 → 5 → 1 → 4
D) 4 → 3 → 1 → 2 → 5

Answer 7

3 → 2 → 5 → 1 → 4