Question 1

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 
D)Parkinson's disease

Accepted Answer

Multiple sclerosis is characterized by the progressive loss of myelin, the fatty substance that surrounds and insulates nerve fibers, in the nervous system. This results in disruptions in nerve impulses and can lead to a wide range of symptoms, including muscle weakness, tremors, and problems with coordination and balance. Huntington's disease, Alzheimer's disease, and Parkinson's disease all involve neurological degeneration, but they do not specifically involve loss of myelin as seen in multiple sclerosis.

Question 2

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.​

Accepted Answer

Ion channels are primarily composed of proteins and operate passively, meaning they do not directly use energy to transport ions across cell membranes.

Question 3

"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.

Accepted Answer

Permeability refers to the ability of substances to pass through a membrane. In the context of a cell, permeability refers to the membrane's ability to control which substances can enter or exit the cell.

Question 4

In Alzheimer's disease,neurofibrillary tangles result when ________ protein levels become elevated and disconnect from microtubules.
A)tetrodotoxin 
B)tau 
C)amyloid 
D)tetanospasmin

Accepted Answer

Neurofibrillary tangles in Alzheimer's disease result from the accumulation of the tau protein, which becomes hyperphosphorylated and separates from microtubules, leading to structural changes in neurons and ultimately cell death.

Question 5

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.

Accepted Answer

Ion selectivity is a characteristic of both ion channels and ion pumps, allowing them to distinguish between different ions based on factors such as size and charge, thus facilitating specific ion transport across cell membranes.

Question 6

Anterograde and retrograde transport within neurons occurs along 
A)microtubules. 
B) neurofilaments.​ 
C)microfilaments. 
D)transport sites.

Accepted Answer

Anterograde and retrograde transport within neurons occurs along microtubules. These microtubules act as railway tracks to transport various cellular components, such as proteins, neurotransmitters, and organelles, to and from different parts of the neuron.

Question 7

A single oligodendrocyte may myelinate axons from an average of _____ different neurons.
A)2 
B)5 
C)10 
D)15

Accepted Answer

A single oligodendrocyte can myelinate axons from approximately 15 different neurons, showcasing its efficiency in the central nervous system by providing myelin sheaths to multiple neurons simultaneously.

Question 8

Which type of glia actually helps guide the regrowth of axons following injury? 
A)astrocytes 
B) oligodendrocytes​ 
C)Schwann cells 
D)microglia

Accepted Answer

Schwann cells are specifically responsible for guiding the regrowth of axons following injury in the peripheral nervous system. Astrocytes play a role in repair and regeneration in the central nervous system, while oligodendrocytes are responsible for producing myelin in the central nervous system. Microglia play a role in immune defense and clearing cellular debris, but not in guiding axon regrowth.

Question 9

The 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 central nervous system.

Accepted Answer

Microglia act as the main phagocytic cells in the central nervous system, engulfing and digesting cellular debris, dead cells, and pathogens.

Question 10

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

Accepted Answer

Microglia have been shown to play a significant role in neuroinflammation in the brain, which can contribute to the development and progression of neurodegenerative diseases such as Alzheimer's and Parkinson's. Astrocytes, oligodendrocytes, and Schwann cells also play important roles in the nervous system, but current research indicates that microglia are the primary type of glia involved in neuroinflammation and neurodegeneration.

Question 11

In a healthy brain,adjacent microtubules are connected by 
A)microfilaments. 
B)neurofilaments. 
C)tau proteins. 
D)phospholipids.

Accepted Answer

Adjacent microtubules in a healthy brain are connected by tau proteins, which help stabilize the microtubules and maintain the structural integrity of neurons. Microfilaments and neurofilaments are also important structural components of neurons, but they do not connect adjacent microtubules. Phospholipids are important components of cell membranes but do not play a direct role in connecting microtubules.

Question 12

In some (although not all)cases of multiple sclerosis,one of the first symptoms noticed is a reduction in sensation from distal parts of the body,such as feet and hands.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 the neural transmission.​ 
D) The neurons have degenerated and are no longer producing neural transmission.​

Accepted Answer

Multiple sclerosis is a disease that attacks the myelin sheaths that surround axons in the nervous system. Demyelination can cause disruptions in neural signaling and can lead to a reduction in sensation in distal parts of the body.

Question 13

The largest of the three types of cytoskeleton fibers are the 
A)microfilaments. 
B) neurofilaments.​ 
C)tau proteins. 
D)microtubules.

Accepted Answer

Microtubules are the largest of the three types of cytoskeleton fibers, with an average diameter of 25 nm. Microfilaments have a diameter of about 7 nm and neurofilaments have a diameter of about 10 nm. Tau proteins are not considered cytoskeleton fibers.

Question 14

The neural cell membrane consists of a(n) 
A)outer layer of protein and an inner layer of phospholipid. 
B) single layer of phospholipids.​ 
C) double layer of phospholipids.​ 
D) double layer of protein.​

Accepted Answer

The neural cell membrane consists of a double layer of phospholipids, also known as a lipid bilayer. The hydrophobic tails of the phospholipids face each other in the middle, while the hydrophilic heads face outward, interacting with the aqueous environment both inside and outside the cell. The membrane also contains various proteins, such as ion channels and receptors, embedded within the phospholipid bilayer.

Question 15

Calcium pumps differ from sodium-potassium pumps in that 
A)they do not require energy in order to operate. 
B) they are rarely found in the central nervous system.​ 
C) they do not collect another type of ion in exchange for the calcium they pump out of the cell.​ 
D) they are not essential for the healthy operation of the nervous system.​

Accepted Answer

Sodium-potassium pumps exchange sodium and potassium ions in and out of the cell, while calcium pumps only pump out calcium ions. Calcium pumps do require energy to operate and are essential for the healthy function of the nervous system.

Question 16

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)phospholipids pumps.

Accepted Answer

Ligand-gated channels are channels that open when they come in contact with specific chemicals or molecules. These channels are found in the nervous system, where they play a critical role in transmitting signals between neurons. When a ligand, such as a neurotransmitter, binds to the channel, it causes the channel to open, allowing ions to pass through and generate an electrical signal.

Option A is incorrect as sodium-potassium pumps are proteins that actively transport Na+ and K+ ions across the cell membrane, maintaining the resting potential of cells.

Option C is also incorrect as voltage-dependent channels open and close in response to changes in the membrane potential, not in response to specific chemicals.

Option D is incorrect as phospholipid pumps do not exist, and pumps in general do not typically refer to ion channels.

Question 17

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.​

Accepted Answer

Sodium-potassium pumps move sodium out of the cell and potassium into the cell, using ATP to power the pumps. This helps to maintain the electrochemical gradient across the cell membrane and is important for many cellular processes.

Question 18

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.​

Accepted Answer

Ion pumps require energy in the form of ATP to actively transport ions across the neural membrane, while ion channels allow ions to passively diffuse across the membrane without requiring energy.

Question 19

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.

Accepted Answer

Sodium-potassium pumps are responsible for maintaining the concentration gradients of sodium and potassium ions across the cell membrane, which is necessary for proper neuronal function. This process consumes a significant amount of energy, accounting for 20 to 40 percent of the energy used by the brain. Calcium pumps, anterograde and retrograde transport within neurons, do not consume as much energy as sodium-potassium pumps.

Question 20

Abnormalities involving which type of cytoskeleton fibers have been implicated in Alzheimer's disease? 
A)microfilaments 
B)neurofilaments 
C)microtubules 
D)sodium-potassium pumps

Accepted Answer

Microtubules have been implicated in Alzheimer's disease as the abnormal accumulation of tau protein leads to destabilization and disintegration of microtubules, ultimately leading to neuronal dysfunction and death.

Quiz 3: Neurophysiology: the Structure and Functions of the Cells of the Nervous System

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

Ion channels are made up of

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

In Alzheimer's disease,neurofibrillary tangles result when ________ protein levels become elevated and disconnect from microtubules.

Ion selectivity is a feature of

Anterograde and retrograde transport within neurons occurs along

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

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

The primary function of microglia is to

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?

In a healthy brain,adjacent microtubules are connected by

In some (although not all) cases of multiple sclerosis,one of the first symptoms noticed is a reduction in sensation from distal parts of the body,such as feet and hands.Which of the following statements best explains why this might happen?

The largest of the three types of cytoskeleton fibers are the

The neural cell membrane consists of a(n)

Calcium pumps differ from sodium-potassium pumps in that

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

Sodium-potassium pumps move

Ion pumps differ from ion channels in that

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

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