nerve cells and cell impulses

The major disadvantage of a blood-brain barrier is that ____.

certain required chemicals must be actively transported

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

Action potentials can be produced in the dendrites of some neurons.

false

The speed of an action potential down an unmyelinated axon is best described as ____.

faster in thick axons than in thin ones

What is the main source of nutrition for vertebrate neurons?

glucose

Radial glia ____.

guide the migration of neurons during embryonic development

The resting potential is mainly the result of ____.

negatively charged proteins inside the cell

Santiago Ramon y Cajal demonstrated that ____.

neurons are separate from one another

When a membrane is at rest, what attracts potassium ions to the inside of the cell?

An electrical gradient

What type of glia helps to synchronize the activity of axons?

Astrocytes

Andrew was exposed to the chicken pox virus as a child. What happened to that virus after it crossed the blood-brain barrier and entered Andrew's brain?

Nothing happened at first, but the virus remained there and caused negative effects for Andrew as he got older.

____ 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

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

Schwann cells

Marquitta is studying for a quiz and records in her notes that glucose is the main source of fuel for the nervous system and enters the brain via _____.

active transport

Mae is studying for an exam on the action potential. She writes in her notes that the sodium channel closes ______.

after the neuron reaches threshold

A presynaptic terminal is also known as ____.

an end bulb

Neurons typically have one ____, but many ____.

axon; dendrites

A drug will prevent an action potential if it ____.

blocks the movement of sodium across the membrane

Dendrites ____.

are branching fibers that get narrower near their ends

There are two types of glial cells that produce myelin sheath. In the central nervous system, Schwann cells fulfill this role and, in the periphery, oligodendrocytes produce it.

false

Under which conditions would the sodium-potassium pump likely be far less effective in creating a concentration gradient?

if selective permeability of the membrane did not exist

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

intrinsic

The structure that contains a cell's chromosomes is called the ____.

nucleus

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

oligodendrocytes

The membrane of a neuron is composed of ____ with ____ embedded in them.

phospholipids; proteins

Dr. McLaughlin's lab studies how newly formed proteins are folded inside neurons. They would be most interested in studying the _____.

ribosomes

Jasmine is in her physiology lab practicing labeling a neuron. When she gets to the nodes of Ranvier, she will be labeling ______.

the gaps in the myelin sheath along the axon

After the peak of an action potential, what prevents sodium ions from continuing to enter the cell?

the sodium gates in the membrane close

The difference in voltage in a resting neuron is called the resting potential.

true