Chapter 2-a Flashcards by Candice Hopkins

Depolarization is to ______ as hyperpolarization is to _____

Excitation inhibition

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Increased permeability to which type of ion would most likely result in an IPSP

Potassium

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A certain week stimulus produces no reflexive response but a rapid repetition of that stimulus may produce such a response what is this phenomenon called

Temporal summation

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What is the primary difference between temporal summation and spatial summation

Spatial summation depends on contributions from more than one sensory neuron

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The spontaneous firing rate of a neuron refers to

It’s rate of producing action potential’s even when it is not stimulated

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Specialized junctions between neurons are called

Synapses

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The decision for a neuron to fire is determined by the

Ratio of EPSP two IPSP

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What determines whether a neuron has an action potential

The combined effects of EPSP and IPSP

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The circuit from sensory neuron to muscle response is called

The reflex arc

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Temporal summation most likely occurs with

Rapid succession of sub threshold excitation

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Spatial summation refers to

Multiple week stimulation is that occur at the same time

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To measure temporal summation in single cells researchers

Record depolarizations of the postsynaptic neuron

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A normal healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time why not

When the interneuron sends excitatory messages to one inhibitory messages go to the other

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A graded depolarization is known as an

EPSP

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Even at rest most neurons have periodic production of action potential’s known as the

Spontaneous firing rate

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What do temporal and spatial summation have in common

Both in able a reflex to occur in response to week stimuli

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What is the proper ordering of a reflex arc

Sensory neuron interneuron motor neuron

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Which process will most likely result in an IPSP

Chloride ions entering the cell

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Which statement is true about the spontaneous firing rates of neurons

EPSPs increase the frequency

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Inhibitory synapses of a neuron

Hyperpolarize the postsynaptic cell

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An EPSP is to _____ as an IPSP is to ______

Depolarization hyperpolarization

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Which statement is true of EPSP

They decay over time and space

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What causes and EPSP

The opening of sodium channels

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In a reflex arc the coordination between contraction of certain muscles and relaxation of others is mediated by

Interneurons

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When a vertebrate animal contract the flexor muscles of a leg it relaxes the extensor muscles of the same leg Sherrington consider this evidence for the existence of

Inhibitory messages

Why is the speed of conduction through a reflex arc slower than the speed of conduction of an action potential along an axon

Transmission between neurons at synapses is lower than a long axons

On the basis of what evidence were the properties of synapses first inferred

Behavioral observations

Sherrington deduced that transmission at a synapse must be slower than conduction along an axon. This was based on what kind of evidence

The speed of reflexive responses

Temporal summation is to ______ as spatial summation is to ______

Time location

The primary difference between an EPSP and an action potential is that

EPSP are sub threshold events that decay over time and space

A temporary hyperpolarization is known as an

IPSP

When an action potential reaches the end of an axon it evokes the release of neurotransmitters by opening what kind of channels in the axon terminal

Calcium

Many neurons release neuropeptides mostly from the

Dendrites

Which event is most likely to be dependent on inotropic effects

Rapid muscle contraction

Inotropic events

May Depol arise or hyperpolarized the postsynaptic membrane

The anterior pituitary is composed of and the posterior pituitary is composed of

Glandular tissue neural tissue

Hormones exert their effects

Similarly to metabotropic neurotransmitters

When an action potential reaches the end of an axon the depolarization causes what ionic movement in the presynaptic cell

Calcium into the cell

The presynaptic terminal stores high concentrations of neurotransmitter molecules in

Vesicles

Releasing hormones are synthesized in the ______ and released in the ______

Hypothalamus anterior pituitary

Which term to refer to a chemical that binds to another chemical

Ligand

The basic building blocks for the majority of neurotransmitters are

Amino acids

The amino acid tryptophan is the precursor to which neurotransmitter

Serotonin

A metabotropic synapse by way of that second messenger

Can influence activity in March or all of the postsynaptic cells

A neuron excretes neurotransmitters through its membrane by a process called

Exocytosis

Which neurotransmitter is released by stimulated neurons to dilate the blood vessels

Nitric oxide

Compared to inotropic effects Metabotrophic effects are

Slower and longer lasting

The primary method for disposal of peptide neurotransmitters is

Diffusion

A hormone is a chemical that is

Conveyed by the blood to other organs his activity it influences

What happens when I neurotransmitter is released by a presynaptic cell

The neurotransmitter passably spreads across the synaptic cleft

ACTH control secretions of the

Adrenal cortex

What do dopamine norepinephrine and epinephrine share in common

They are all synthesized from the same amino acids

Loewi demonstrated that synapses operate by the release of chemicals by

Collecting fluid for my stimulated frogs heart transferring it to another frogs heart and measuring that heart rate

What makes nitric oxide unique among neurotransmitters

It is a gas

The main advantage of a neuron releasing more than one neurotransmitter is that

It can send more complex messages

What happens to acetylcholine after it attaches to a receptor on the postsynaptic cell

It is broken down into two components

You were eating a food containing tryptophan what can you consume with it to increase its entry to the brain

Carbohydrates

Transporter proteins transport neurotransmitters to

Back into the presynaptic neuron

Autoreceptors monitor the

Amount of neurotransmitter released

A drug that inhibits the action of the enzyme acetylcholinesterase will have the effect of

prolonging the action of acetylcholine at its synapses

IN addition to influencing other neurons, ____ increases blood flow to a specific area of the brain

Nitric Oxide

Although slower than an action potential, synaptic transmission is still relatively fast because

the synaptic cleft is very narrow

Avoiding foods with lecithin, such as eggs and peanuts, would affect the levels of which neurotransmitter the most

actylecholine

Vesicles are located in the

presynaptic terminals

The catecholamines include

epinephrine, norepinephrine and dopamine

Neuropeptides are synthesized in the

cell body.

which category of chemicals includes adenosine and several of its derivatives

purines

COMT and MAO are

enzymes that convert catecholamines into inactive chemicals

Receptor molecules for neurotransmitters that exert metabotropic effects are proteins that bind to ____ outside the membrane, and attach to _____ inside the membrane

Neurotransmitters, g-proteins

"second messengers" carry their messages to

areas within the postsynaptic cell

Activation of autoreceptors tends to

decrease further neurotransmitter release

Ionotropic effects are characterized by

rapid and short lived effects

the effect of a neurotransmitter on a postsynaptic neuron is determined by the

receptors on the postsynaptic membrane

In general, a single neuron releases ____ neurotransmitters and can respond to ____ neurotransmitters

several, many

What is the synaptic cleft

the gap between the presynaptic neuron and the post synaptic neuron

Glutamate opens sodium gates, enabling sodium ions to enter the postsynaptic cell. What type of effect is this?

inotropic

A receptor can directly open a channel and thereby exert an ____ effect, or it can produce slower but longer ____

ionotropic. metabotropic

Which one of Sherrington's inferences about the synapse was WRONG?

Transmission at the synapse is primarily an electrical process

Which process is more typical of a metabotropic effect than an ionotropic effect?

producing long-lasting effects on the post-synaptic cell

the neuron that receives the message is called the

postsynaptic

Professor Deshon is lecturing about EPSPs and IPSPs. He tells the class that in order to produce an IPSP, there needs to be an increase in permeability for

chloride

Nitric Oxide can function as a hormone? True or False

false

An EPSP is to ____ as an IPSP is to _____

Depolarization, hyperpolarization