Chapter 12 Quiz Questions

This figure shows the three main functional classes of neurons. Which option below correctly matches the types of neuron to the numeric labels on the figure?

1-Afferent neuron, 2-Interneuron, 3-Efferent neuron

Which of the following is true regarding axons in the PNS?

A Schwann cell folds its plasma membrane around several axons.

Conduction of a nerve impulse would be the fastest in which of the following?

A large diameter myelinated axon

A neuron receives a stimulus. Which of the following events happens next?

A local potential develops

Which of these is an example of an EPSP in a typical neuron?

A voltage change from -70 mV to -69.5 mV

Which neurotransmitter excites skeletal muscle and inhibits cardiac muscle?

Acetylcholine

How does a neuron transport enzymes produced in the cell body to its axon terminals?

Along microtubules

Which statement about the nervous and endocrine systems is true?

Both systems are dedicated to maintaining stable internal conditions by detecting and responding to stimuli.

Place the following events in synaptic transmission at a cholinergic synapse in order: A - A postsynaptic potential is produced; B - Voltage-gated calcium channels open and calcium enters the cell; C - ACh is released and diffuses across the axon terminal; D - A nerve signal arrives at an axon terminal; E - Ligand-gated sodium channels open and sodium enters the cell.

D, B, C, E, A

In which part of a neuron is the postsynaptic membrane usually found?

Dendrite

Parkinson disease is a progressive loss of motor function due to the degeneration of specific neurons. These neurons secrete an inhibitory neurotransmitter that prevents excessive activity in motor centers of the brain. What neurotransmitter is this?

Dopamine

What would be the best explanation for why myelinated axons conduct signals faster than unmyelinated axons?

Electrical signals spread faster through insulated (myelinated) regions of axon.

Inhibitory postsynaptic potentials (IPSPs) are associated with which of the following?

Hyperpolarization of the cell membrane

In an action potential, which event directly follows repolarization?

Hyperpolarization of the membrane

Some antidepressant drugs act by inhibiting monoamine oxidase (MAO). What is the function of this enzyme?

It breaks down monoamines.

What is the most common type of neuron?

Multipolar

During the absolute refractory period which of the following is true?

No stimulus of any strength will trigger a new action potential.

Which cells form myelin sheaths in the spinal cord?

Oligodendrocytes

Which of the following is most likely to cause a rapid depolarization?

Opening of sodium channels

Which of the following ions has the greatest influence on the resting membrane potential?

Potassium

What causes hyperpolarization of a neuronal membrane?

Potassium ions leave the cell.

Which glial cell is found wrapped around axons in the PNS?

Schwann cells

Most metabolic and regulatory functions in a neuron happen where?

The cell body

What is the primary site on a neuron for receiving signals from other neurons?

The dendrites

While both systems maintain homeostasis, how does the nervous system differ from the endocrine system?

The nervous system releases neurotransmitters between cells, while the endocrine system releases hormones into the blood.

Which of these happens first in a cholinergic synaptic transmission?

The synaptic vesicles release acetylcholine.

What is another name for the autonomic nervous system?

Visceral motor division

A cholinergic synapse uses _________ as its neurotransmitter.

acetylcholine

Some _________ neurons are specialized to detect stimuli, whereas _________ neurons send signals to the effectors of the nervous system.

afferent; efferent

The term "nerve fiber" refers to a(n) _________

axon

The opening of _________ gates produces an _________.

chloride; IPSP

The respiratory center gathers information from a variety of sources in order to set the rate and depth of breathing. This is an example of what type of neural circuit?

convergent

Local potentials are _________, meaning they vary in magnitude according to the strength of the stimulus.

graded

Where are axons surrounded by Schwann cells found?

in the PNS

A myelin sheath is composed primarily of _________

lipids and proteins

When the voltage of a plasma membrane shifts from +35 mV toward 0 mV, the cell is _________

repolarizing

If a neuron is prevented from sending a neurotransmitter across a synapse to another cell, which neuron property is being inhibited?

secretion

The _________ division tends to prepare the body for action

sympathetic

All of the following are typical characteristics of neurotransmitters except _________

they are released into the bloodstream before reaching the postsynaptic cell

The _________ division carries signals to the smooth muscle in the large intestine.

visceral motor

What is the most common inhibitory neurotransmitter in the brain?

γ-Aminobutyric acid (GABA)