Module 2.1

Glucose enters the brain via:

active transport

Which type of glia remove waste material in the nervous system?

astrocytes

Glial cells:

do not transmit information over long distances

The cell membrane is comprised of two layers of:

fat.

What is the main source of nutrition for vertebrate neurons?

glucose

The endoplasmic reticulum is a:

network of thin tubes that transport newly synthesized proteins.

Which chemicals flow most freely across a cell membrane?

water, oxygen, and carbon dioxide

The risk of having part of the brain unprotected by the blood-brain barrier is:

Both chemical interference with neurotransmitters and increased risk from viruses and toxic chemicals are correct

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

Some dendrites contain additional short outgrowths. What are these outgrowths called?

Dendritic spines

Which of the following is NOT a characteristic of an axon?

It carries information toward the cell body

What happens to a virus that manages to cross the blood-brain barrier and enter the brain?

It stays in the nervous system throughout the person's life.

Why do neurons rely so heavily on glucose as their source of nutrition?

Other fuels do not readily cross the blood-brain barrier.

Which type of glia builds myelin sheaths around axons in the periphery of the body?

Schwann cells.

Prior to the work of Santiago Ramon y Cajal, what did many investigators believe?

The tip of an axon physically merged with the next neuron.

Which of the following is a characteristic of glial cells in the human brain?

They are more numerous than neurons.

Which of the following is NOT true of axons?

They carry information toward the soma

Which of the following is NOT true of astrocytes?

They make up the myelin sheaths in the periphery of the body

What is the mechanism that prevents or slows some chemicals from entering the brain, while allowing others to enter?

a blood-brain barrier

Who is most likely to suffer from a thiamine deficiency?

alcoholics

A presynaptic terminal is also known as:

an end bulb

Dendrites ____.

are branching fibers that get narrower near their ends

One type of glia helps synchronize the activity of axons. They are called:

astrocytes.

Which type of glia release chemicals that modify the activity of neighboring neurons?

astrocytes.

As a general rule, where do axons convey information?

away from their own cell body

The information sender of the neuron, conveying an impulse toward either other neurons or a gland or muscle is called the:

axon

Neurons typically have one ____, but many ____.

axon; dendrites

Water, oxygen and ____ most freely flow across a cell membrane.

carbon dioxide

The major disadvantage of a blood-brain barrier is that:

certain required chemicals must be actively transported.

Which of the following is the correct order of transmission of information within a neuron?

dendrite, cell body, axon

Incoming synapses are primarily found on:

dendrites and cell bodies.

The branching fibers that form the information-receiving pole of the nerve cells are called:

dendrites.

The tree-like branches of a neuron that receive information from other neurons are called:

dendrites.

In the brain, an arrangement of endothelial cells:

does not allow most molecules to pass because the cells are so tightly packed.

If you were to accidentally touch a hot stove with your hand, you would quickly pull your hand away. The information carried to the muscles in your arm to make them contract was carried by:

efferent neurons

Nodes of Ranvier are:

gaps in the myelin of axons.

Radial glia:

guide the migration of neurons during embryonic development.

A greater amount of branching on dendrites allows them to:

have a larger surface area available for receiving information from other neurons.

Of the following, the most important consideration in developing a drug that will act in the brain is:

if the drug will cross the blood-brain barrier.

Many dendrites contain short outgrowths called spines which:

increase the surface area available for synapses

Chemicals are released by axons:

into the junction between neurons.

If all of a neuron's dendrites or axons were contained within the spinal cord, it would be considered a(n) ____ neuron.

intrinsic

What would a neuron in the pons be called that receives information only from other cells in the pons and sends information only to other cells in the pons?

intrinsic

Korsakoff's syndrome:

is marked by severe memory impairments.

Which of the following is NOT a characteristic of a dendrite?

it is in contact with the dendrites of other neurons.

In contrast to dendrites, axons:

may be covered with myelin.

Glial cells whose function most closely resembles that of the immune system are called:

microglia.

Where do the metabolic activities occur that provide energy for all of the other activities of the cell?

mitochondria

Molecules that can cross the blood-brain barrier are usually:

molecules which can dissolve in the fats of the capillary walls.

What receives excitation from other neurons and conducts impulses to muscle or gland cells?

motor neurons

The insulating material which covers many vertebrate axons is called the:

myelin sheath.

What are the two kinds of cells in the nervous system?

neurons and glia

Santiago Ramon y Cajal demonstrated that:

neurons are separate from one another.

Gaps in the insulating material that surrounds axons are known as:

nodes of Ranvier.

The structure that contains the chromosomes is called the:

nucleus.

Glial cells:

occupy about the same total space as do neurons.

What type of glial cells myelinate axons in the brain and spinal cord?

oligodendrocytes

____ in the brain and spinal cord and ____ in the periphery are specialized types of glia that build the myelin sheaths that surround neurons.

oligodendrocytes; schwann cells

An axon has many branches, each of which swells at its tip. These are known as:

presynaptic terminals

Compared to passive transport, the major disadvantage of active transport is that it:

requires expenditure of energy.

The sites at which the cell synthesizes new protein molecules are called:

ribosomes.

Neurons differ most strongly from other body cells in their:

shape.

The ____ of neurons most strongly differentiate them from other cells in the body.

shape.

Protein channels, allow ____ to cross the cell membrane.

small charged molecules

Which of the following is most likely to cross the cell membrane by simple diffusion?

small, uncharged molecules

Which would be MOST likely to cross the blood-brain barrier?

small, uncharged molecules

Myelin covers:

some axons in vertebrates and none in invertebrates

Chemicals than cannot flow freely across a cell membrane enter a neuron through:

specialized protein channels

Ribosomes are the part of a cell that:

synthesizes new proteins.

What structure is composed of two layers of fat molecules that are free to flow around one another?

the membrane

What is the point from which an axon releases chemicals into the synapse?

the presynaptic terminal

What are two requirements for the brain to metabolize glucose?

thiamine and oxygen

What leads to Korsakoff's syndrome?

thiamine deficiency resulting from alcoholism

Why does the brain need thiamine?

to enable it to metabolize glucose

Which function is NOT performed by glia?

transmitting information