Nervous System Levels of Organization

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What is the most abundant glial cell in the brain?

Oligodendrocytes

Astrocytes (correct)

Ependymal cells

Radial glia

Which of the following is not a function of a Satellite glial cell?

Conduction of nervous impulses along axons (correct)

Regulate the chemical environment

Supply nutrients to surrounding neurons

Protect/cushion neuron cell bodies

Which of the following is not characteristic of white matter?

Responsible for modulation of the distribution of action potentials

It is the tissue through which messages pass between different areas of gray matter

Made up of neuronal cell bodies (correct)

Composed of bundles of myelinated nerve cell processes

Which of the following ions does not play a role in creating the transmembrane potential?

Oxygen Signup and view all the answers

In the resting state of the cell, which ion is found at a concentration of 145 mM in the extracellular fluid?

Sodium Signup and view all the answers

How is the resting membrane potential of a cell maintained?

The Sodium-Potassium pump actively transports 3 sodium ions out of the cell for every 2 potassium ions brought into the cell Signup and view all the answers

What causes depolarization of a neuron?

Sodium gates open, allowing sodium to flood into the cell and make the membrane potential less negative Signup and view all the answers

What is the definition of an action potential?

The rapid rise and drop in membrane potential that occurs when a neuron fires Signup and view all the answers

What is the definition of a synapse?

Specialized junctions through which neurons can signal to each other and other cells via neurotransmitter molecules. Signup and view all the answers

What is temporal summation of synaptic potentials?

When successive EPSPs at a single synapse occur in rapid succession. The successive potentials occur before the previous ones die out producing an increasing membrane depolarization Signup and view all the answers

Which of the following is not a class of neurotransmitter?

Nucleotides Signup and view all the answers

The ion that enters a presynaptic axon terminal and that directly causes the release of a neurotransmitter substance from the presynaptic terminal is:

Calcium Signup and view all the answers

Any change in a neuron’s membrane potential that moves the membrane potential to a value more negative than the resting potential (e.g. -120mv) is:

Hyperpolarization Signup and view all the answers

Which of the following is not a function of the autonomic nervous system?

Movement Signup and view all the answers

The secretions of the adrenal medulla act to supplement the effects of:

sympathetic stimulation Signup and view all the answers

The dryness of the mouth (cotton mouth) that occurs when some people are called upon to give an extemporaneous speech is the result of a:

sympathetic inhibition of the salivary glands Signup and view all the answers

Regarding the functions of the autonomic nervous system, an individual at rest, digesting a large meal, would be primarily under the influence of the:

parasympathetic system Signup and view all the answers

Postganglionic fibers of the parasympathetic division of the ANS release:

acetylcholine Signup and view all the answers