Chapter 10 A&P I

Migraine results from

release of calcitonin gene-related peptide from the trigeminal nerves at the base of the brain, in response to a spreading wave of excitation followed by lack of response from the cortex.

Every neuron has

a cell body.

Myelin is rich in

lipids

When an action potential passes over the surface of the synaptic knob, the contents of the vesicles are released in response to the presence of

Calcium ions

Saltatory conduction

is faster than conduction on an unmyelinated fiber.

Each neuron in the CNS receives input from

...

The neurotransmitter that controls skeletal muscle contraction is

acetylcholine

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are more likely used to treat

Clinical depression.

Opiate drugs derived from poppies relieve pain in humans because the human nervous system has

receptors for endogenous opiates.

A drug that functions as an agonist

activates a receptor, helping a neurotransmitter bind or triggering an action potential in some way.

When a nerve fiber is polarized, the concentration of

Na+ is higher on the outside of the membrane and K+ is higher on the inside

Which of the following ions cross cell membranes most readily?

Potassium

If a resting potential becomes more negative, the membrane is

hyper polarizing.

The cytoplasmic extensions that, together with the cell body, provide the main receptive surfaces for neurons are

dendrites

The two types of cells of the nervous system are

neurons and neuroglia.

The space between neurons is a

synapse.

Neurons that convey impulses from the CNS to muscles or glands are

effectors.

Sensory receptors

all of the above

Three general functions of the nervous system are

integrative, motor, and sensory.

Masses of myelinated nerve fibers appear

white

A neuron may have

one axon and many dendrites.

______ support the axon from within.

Neurofibrils.

Which of the following is unique to neurons

Chromatophilic substance

Myelin

comprises much of the cell membrane of Schwann cells.

A myelinated nerve fiber is ____, whereas an unmyelinated nerve fiber is ____.

white, and composing the white matter of the brain and spinal cord; gray, and composing the gray matter of the brain and spinal cord

Which of the following are type of neuroglia?

all of the above

Which cells produce myelin in the brain and spinal cord?

...

Most of the neurons in the brain and spinal cord are

multipolar.

Which of the following cells is only found in the PNS?

Schwann cell

Dendrites on unipolar neurons are part of

sensory neurons.

clusters of neuron cell bodies are called ____.

ganglia

Which of the following neuroglia is not part of the CNS?

Satellite cells

synaptic knobs are at the ends of

axons.

Presynaptic neurons release neurotransmitters by ______.

exocytosis.

When an action potential passes over the surface of a synaptic knob, the contents of the vesicles are released in response to the presence of

calcium ions.

if a neuron receives a series of stimuli whose effect is excitatory but sub threshold, the neuron is more excitable to incoming stimulation than before and is said to be

facilitated.

Transmitting a nerve impulse from one neuron to another involves a

nerve impulse stimulating a presynaptic axon to release a neurotransmitter into a synaptic cleft.

Action potentials are related to nerve impulses in that

...

A stimulus great enough to change the membrane potential and propagate an action potential is said to have reached

threshold

What is the correct sequence of events that follows a threshold potential?

2,1,4,3

A nerve cell membrane may become depolarized as a result of

some ion channels being opened while others are closed.

An excitatory postsynaptic potential last for about

15 milliseconds

Viagra is a drug used to treat erectile dysfunction by dilating arteries in the penis. The neuro transmitter that Viagra affects is

nitric oxide.

Neurotransmiters that are modified amino acids are

...

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are most likely used to treat

clinical depression

in reuptake

a neurotransmitter that has already been released into the synaptic cleft is taken back into the synaptic knob of the presynaptic neuron or into nearby neuroglia or neurons.

Drugs that inhibit the enzyme monoamine oxidase

allow increased activity of norepinephrine.

The types of neurons that are organized into neuronal pools are

interneurons

Convergence refers to

axons from neurons in different parts of the nervous system contacting the same neuron.

Diverging axons amplify an impulse by

contacting many neurons

Neural stem cells can be harvested from autopsies and stored, alive, in banks, whereas neurons cannot, because

neural stem cells have lower oxygen and energy requirements than neurons.

Multiple sclerosis is caused by an abnormal response of the

immune system

An immune response that triggers inflammation of the spinal cord and brain, leaving scars is

multiple sclerosis

opiate drugs derived from poppies relieve pain in humans because the human nervous system has

receptors for endogenous opiates.

Marjorie takes an anti-anxiety drug so that she can sleep better and remain calm enough to study effectively. She begins by taking 25milligrams every evening, but within a month, this dose is no longer helping, so she takes two pills. After another month, this dosage is no longer effective. this is happening because

The number of receptors to which the drug binds on neurons has declined.

The neurotransmitter is most likely produced when a person uses a drug that creates a sense of well-being is

dopamine

A drug that functions as an agonist

activates a receptor, helping a neurotransmitter bind or triggering an action potential in some other way.