Deck 3: Neurophysiology: The Structure and Functions of the Cells of the Nervous System

Question 1

 An important function of the astrocytes is to regulate the chemical environment of the synaptic gap. The ability of astrocytes to remove which of the following chemicals from the synaptic gap is especially important?

A) magnesium
B) potassium
C) sodium
D) tetrodotoxin

Answer 1

potassium

Question 2

 There are many more neurons than glia in the nervous system.

Answer 2

False

Question 3

 Oligodendrocytes form the myelin sheaths in the central nervous system (CNS).

Answer 3

True

Question 4

 Presynaptic facilitation occurs at a synapse between a presynaptic axon and a postsynaptic dendrite and leads to more frequent signaling by the postsynaptic cell.

Question 5

 The most common type of glia in the brain is the

A) astrocyte.
B) oligodendrocyte.
C) Schwann cell.
D) microglia.

Question 6

 Which type of glia may actually participate in neural communication?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 7

 Excitatory postsynaptic potentials (EPSPs) can last 5 to 10 times as long as an action potential.

Question 8

 Which type of glia is responsible for forming myelin in the peripheral nervous system (PNS)?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 9

 A single oligodendrocyte may myelinate axons from an average of _____ different neurons.

A) 2
B) 5
C) 10
D) 15

Question 10

 Many common brain disorders, including stroke, may result in damage due to the release of the amino acid glutamate by

A) astrocytes.
B) oligodendrocytes.
C) Schwann cells.
D) microglia.

Question 11

 A structural matrix for neurons is provided by

A) astrocytes.
B) oligodendrocytes.
C) Schwann cells.
D) microglia.

Question 12

 The glia that participate in the formation of the blood-brain barrier are the

A) astrocytes.
B) oligodendrocytes.
C) Schwann cells.
D) microglia.

Question 13

 Following injury, which type of glia may actually inhibit neural regrowth by forming scar tissue?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 14

 Bipolar neurons have two branches leaving the cell body and are frequently found in the sensory systems of mammals.

Question 15

 A single Schwann cell may myelinate axons from an average of _____ different neurons.

A) only 1
B) 2 to 5 axons
C) 6 to 10
D) 15 or more

Question 16

 Which type of glia is responsible for forming myelin in the CNS?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 17

 Additional action potentials can occur in response to stronger-than-normal stimulation during a neuron's absolute refractory period.

Question 18

 Mitochondria produce proteins in the neural cell body.

Question 19

 The amount of neurotransmitter released during exocytosis is largely determined by the amount of calcium entering the presynaptic axon terminal.

Question 20

 Microtubules are the largest type of fibers found in the neural cytoskeleton.

Question 21

 In a healthy brain, adjacent microtubules are connected by

A) microfilaments.
B) neurofilaments.
C) tau proteins.
D) phospholipids.

Question 22

 In Alzheimer's disease, neurofibrillary tangles result when ________ proteins levels disconnect from microtubules.

A) tetrodotoxin
B) tau
C) amyloid
D) tetanospasmin

Question 23

 Ion channels are made up of

A) proteins and require energy in order to operate.
B) lipids and require energy in order to operate.
C) proteins and do not expend energy in order to operate.
D) lipids and do not require energy in order to operate.

Question 24

 Which of the types of cytoskeleton fiber may be involved with structural changes in response to learning?

A) microfilaments
B) neurofilaments
C) tau proteins
D) microtubules

Question 25

 Which of the following disorders is characterized by a progressive demyelination of the nervous system?

A) Huntington's disease
B) Alzheimer's disease
C) Multiple sclerosis (MS)
D) Parkinson's disease

Question 26

 The largest of the three types of cytoskeleton fibers are the

A) microfilaments.
B) neurofilaments.
C) tau proteins.
D) microtubules.

Question 27

 Sodium-potassium pumps move

A) potassium out of the cell and sodium into the cell.
B) sodium out of the cell and potassium into the cell.
C) both sodium and potassium into the cell.
D) both sodium and potassium out of the cell.

Question 28

 Abnormalities involving which type of cytoskeleton fibers have been implicated in Alzheimer's disease?

A) microfilaments
B) neurofilaments
C) microtubules
D) sodium-potassium pumps

Question 29

 Anterograde and retrograde transport within neurons occurs along

A) microtubules.
B) neurofilaments.
C) microfilaments.
D) transport sites.

Question 30

 As much as 20 to 40 percent of the energy required by the brain is used by

A) sodium-potassium pumps.
B) calcium pumps.
C) anterograde transport within neurons.
D) retrograde transport within neurons.

Question 31

 Dr. Janelle notices that in some (although not all) cases of multiple sclerosis (MS) one of the first symptoms is tingling or pain. Which of the following statements best explains why this might happen?

A) The fibers of the axons are reduced in diameter, so the information can't travel fast enough.
B) Neural signaling may not work properly as a result of nervous system demyelination.
C) The fibers of the axons are enlarged, slowing neural transmission.
D) Potassium is not cleared from the synapse efficiently, leading to fewer action potentials.

Question 32

 Calcium pumps differ from sodium-potassium pumps in that they

A) do not require energy in order to operate.
B) are rarely found in the CNS.
C) do not collect another type of ion in exchange for the calcium they pump out of the cell.
D) are not essential for the healthy operation of the nervous system.

Question 33

 "Permeability" refers to the ability of the cell's

A) axons to form connections with other neurons.
B) microtubules to transport substances within the cell.
C) dendrites to receive information from other neurons.
D) membrane to control the movement of substances into or out of the cell.

Question 34

 Which type of glia actually helps guide the regrowth of axons following injury?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 35

 A primary function of microglia is to

A) digest debris.
B) provide a structural matrix for neurons.
C) participate in forming the blood-brain barrier.
D) form myelin in the CNS.

Question 36

 Ion selectivity is a feature of

A) both ion channels and ion pumps.
B) neither ion channels nor ion pumps.
C) ion channels but not ion pumps.
D) ion pumps but not ion channels.

Question 37

 The neural cell membrane consists of a(n)

A) outer layer of proteins and an inner layer of phospholipids.
B) single layer of phospholipids.
C) double layer of phospholipids.
D) double layer of proteins.

Question 38

 Channels that open when they come in contact with specific chemicals are known as

A) sodium-potassium pumps.
B) ligand-gated channels.
C) voltage-dependent channels.
D) phospholipid pumps.

Question 39

 Ion pumps differ from ion channels in that

A) they allow different types of ions to cross the neural membrane.
B) pumps respond to ligands and drugs, whereas channels respond to the electrical environment in their immediate vicinity.
C) channels require energy to operate, whereas pumps do not.
D) pumps require energy to function, whereas channels do not.

Question 40

 Inflammation caused by which of the following types of glia is believed to contribute to neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease?

A) astrocytes
B) oligodendrocytes
C) Schwann cells
D) microglia

Question 41

 Proteins produced in the cell body are packaged by the

A) endoplasmic reticulum.
B) nucleolus.
C) mitochondria.
D) Golgi apparatus.

Question 42

 The uncovered section of axon membrane between two segments of myelin is known as a(n)

A) axon terminal.
B) axon hillock.
C) collateral.
D) node of Ranvier.

Question 43

 Ribosomes are built by the

A) endoplasmic reticulum.
B) nucleolus
C) mitochondria.
D) Golgi apparatus.

Question 44

 The diameter of an axon is correlated with

A) the age of the organism.
B) the speed of signaling in the axon.
C) the number of synapses formed by the axon.
D) whether or not learning has occurred.

Question 45

 Which of the types of cytoskeleton fiber run parallel to the length of axons, providing structural support for the cell?

A) microfilaments
B) neurofilaments
C) tau proteins
D) microtubules

Question 46

 The swelling at the end of an axon is known as an axon

A) spine.
B) hillock.
C) collateral.
D) terminal.

Question 47

 Which of the following structures are typically found within the axon terminal?

A) mitochondria and synaptic vesicles
B) the nucleolus and synaptic vesicles
C) myelin and mitochondria
D) the nucleolus and endoplasmic reticulum

Question 48

 The substructure within a neuron's cell body that contains the cell's DNA is called the ________.

A) axon
B) dendrite
C) nucleus
D) nucleolus

Question 49

 Knobs located on the dendrites that provide additional locations for synapses are known as dendritic

A) spikes.
B) spines.
C) filopodia.
D) lamellipodia.

Question 50

 Larger diameter axons usually transmit information _________ smaller diameter axons.

A) faster than
B) more slowly than
C) at the same rate as
D) using less energy than

Question 51

 The branches formed at the end of an axon that is closest to its target are known as

A) spines.
B) hillocks.
C) collaterals.
D) spikes.

Question 52

 Neurons with short axons that communicate primarily with adjacent cells are known as _________ neurons.

A) sensory
B) motor
C) projection
D) local circuit

Question 53

 The most numerous of the cytoskeleton fibers are the

A) microtubules.
B) microfilaments.
C) dendritic spines.
D) neurofilaments.

Question 54

 A neural structure that typically carries messages to other neurons is known as a(n)

A) axon.
B) dendrite.
C) spine.
D) filopodium.

Question 55

 The organelles responsible for providing energy for the cell are the

A) endoplasmic reticulum.
B) nucleolus.
C) mitochondria.
D) Golgi apparatus.

Question 56

 Similar to a neuron's cell membrane, synaptic vesicles are made of a(n)

A) outer layer of proteins and an inner layer of phospholipids.
B) single layer of phospholipids.
C) double-lipid molecule structure.
D) double layer of proteins.

Question 57

 Branches that serve as locations at which information is received from other neurons are known as

A) dendrites.
B) ribosomes.
C) mitochondria.
D) cell bodies.

Question 58

 Neurochemicals in the axon terminal are often contained within

A) mitochondria.
B) synaptic vesicles.
C) ribosomes.
D) nodes of Ranvier.

Question 59

 The initial cone-shaped segment of an axon at the junction with the cell body is known as the axon

A) spine.
B) spike.
C) hillock.
D) terminal.

Question 60

 The primary function of the neurofilaments is

A) providing structural support for the neuron.
B) the transport of organelles to the end of the axon.
C) the transport of organelles back to the cell body.
D) increasing the permeability of the neuron's cellular membrane.

Question 61

 Myelinated axons have large numbers of ion channels

A) along the entire length.
B) at the axon hillock and nodes of Ranvier.
C) only at the axon terminals.
D) only at the axon hillock.

Question 62

 Extracellular fluid is most similar in chemical composition to

A) fresh water.
B) seawater.
C) alcoholic beverages.
D) caffeinated energy drinks.

Question 63

 Bipolar neurons have _________ leaving the cell body.

A) one branch
B) one axon and many dendrites
C) two branches
D) one dendrite and many axons

Question 64

 Von Economo neurons are found in

A) both invertebrates and vertebrates.
B) all vertebrates but not in any invertebrates.
C) all mammals but not in other types of animals.
D) humans, elephants, great apes, and members of the whale family.

Question 65

 Intracellular fluid is rich in

A) K+, with small amounts of Na+ and Cl?.
B) K+ and Cl?, with very small amounts of Na+.
C) Cl?, with very small amounts of K+ and Na+.
D) Na+ and Cl?, with small amounts of K+.

Question 66

 Compared with the myelin found on small diameter axons, the myelin coating axons of large diameter axons

A) is of equal thickness and spacing.
B) has less thickness but equal spacing.
C) has equal thickness, but the nodes of Ranvier are closer together.
D) is thicker, and the nodes of Ranvier are farther apart.

Question 67

 Professor Winston is observing the effects of a new drug on neurons in the spinal cord that participate in reflexes by forming a bridge between incoming sensory information and outgoing motor commands. The neurons that Professor Winston is studying are most likely

A) sensory neurons.
B) motor neurons.
C) interneurons.
D) von Economo neurons.

Question 68

 Compared with unmyelinated axons, myelinated axons

A) use more energy to transmit a neural message.
B) have wider nodes of Ranvier.
C) have narrower nodes of Ranvier.
D) use less energy to transmit a neural message.

Question 69

 Extracellular fluid is rich in

A) K+, with small amounts of Na+ and Cl?.
B) K+ and Cl?, with very small amounts of Na+.
C) Cl?, with very small amounts of K+ and Na+.
D) Na+ and Cl?, with small amounts of K+.

Question 70

 Neurons that are specialized to transmit commands from the CNS to glands and muscles are known as

A) sensory neurons.
B) motor neurons.
C) unipolar neurons.
D) interneurons.

Question 71

 In vertebrates, unipolar cells are common in the

A) cerebral cortex.
B) cerebellum.
C) sensory systems.
D) motor systems.

Question 72

 Unipolar neurons have _________ leaving the cell body.

A) one branch
B) one axon and many dendrites
C) two branches
D) one dendrite and many axons

Question 73

 The most common structural type of neuron in the vertebrate nervous system is the

A) unipolar neuron.
B) bipolar neuron.
C) multipolar neuron.
D) interneuron.

Question 74

 Neurons that are specialized to receive information from the outside world are known as

A) sensory neurons.
B) motor neurons.
C) multipolar neurons.
D) interneurons.

Question 75

 Neurons that are not specialized for either sensory or motor functions are known as

A) sensory neurons.
B) motor neurons.
C) unipolar neurons.
D) interneurons.

Question 76

 Pyramidal cells in the cerebral cortex are examples of

A) unipolar neurons.
B) bipolar neurons.
C) multipolar neurons.
D) Purkinje cells.

Question 77

 Von Economo neurons probably participate in which of the following functions?

A) assessing and performing complex social behaviors
B) regulation of important body functions, including temperature, hunger, and thirst
C) processing of complex visual stimuli
D) reflexive motor behaviors

Question 78

 A von Economo neuron is a special type of _________ neuron

A) unipolar
B) bipolar
C) multipolar
D) sensory

Question 79

 The vast majority of neurons are classified as

A) sensory neurons.
B) motor neurons.
C) spinal neurons.
D) interneurons.

Question 80

 Multipolar neurons have _______________leaving the cell body.

A) one branch
B) one axon and many dendrites
C) two processes
D) one dendrite and many axons