Biological Psychology Chapter 2 Kalat

The circuit from sensory neuron to muscle response is called ____.

A reflex arc

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

Acetylcholine

Adrenocorticotropic hormone (ACTH) controls secretions of the ____.

Adrenal cortex

The basic building blocks for the majority of neurotransmitters are ____.

Amino acids

Autoreceptors monitor the ____.

Amount of neurotransmitter released

"Second messengers" carry their messages to ____.

Areas within the postsynaptic cell

"Transporter" proteins transport neurotransmitters ____.

Back into the presynaptic neuron

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

Behavioral observations

What do temporal summation and spatial summation have in common?

Both enable a reflex to occur in response to weak stimuli.

When an action potential reaches the end of an axon, it evokes the release of neurotransmitters by opening ____ channels in the axon terminal.

Calcium

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

Calcium into the cell

A metabotropic synapse, by way of its second messenger, ____.

Can influence activity in much or all of the postsynaptic cell

You are eating a food containing tryptophan. What can you consume with it to increase its entry to the brain?

Carbohydrates

Neuropeptides are synthesized in the ____.

Cell body

Which process will most likely result in an IPSP?

Chloride ions entering the cell

Loewi demonstrated that synapses operate by the release of chemicals by ____.

Collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate

A hormone is a chemical that is ____.

Conveyed by the blood to other organs, whose activity it influences

Activation of autoreceptors tends to ____.

Decrease further neurotransmitter release

Many neurons release neuropeptides mostly from the ____.

Dendrites

An EPSP is to ____ as an IPSP is to ____.

Depolarization; hyperpolarization

The primary method for disposal of peptide neurotransmitters is ____.

Diffusion

A graded depolarization is known as an ____.

EPSP

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

EPSPs are sub-threshold events that decay over time and space

Which statement is TRUE about the spontaneous firing rates of neurons?

EPSPs increase the frequency

COMT and MAO are ____.

Enzymes that convert catecholamines into inactive chemicals

The catecholamines include ____.

Epinephrine, norepinephrine, and dopamine

Depolarization is to ____ as hyperpolarization is to ____.

Excitation; inhibition

A neuron excretes neurotransmitters through its membrane by a process called ____.

Exocytosis

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

Glandular tissue; neural tissue

Inhibitory synapses on a neuron ____.

Hyperpolarize the postsynaptic cell

Releasing hormones are synthesized in the ____ and released in the ____.

Hypothalamus; anterior pituitary

A temporary hyperpolarization is known as an ____.

IPSP

Vesicles are located ____.

In presynaptic terminals

When a vertebrate animal contracts the flexor muscles of a leg, it relaxes the extensor muscles of the same leg. Sherrington considered this evidence for the existence of ____.

Inhibitory Messages

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

Interneurons

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

Ionotropic

A receptor can directly open a channel and thereby exert a(n) ____ effect, or it can produce slower but longer ____ effects.

Ionotropic; metabotropic

What is the function of the enzyme acetylcholinesterase?

It breaks acetylcholine down into components for recycling.

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

It can send more complex messages

What makes nitric oxide unique among neurotransmitters?

It is a gas

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

It is broken down into two components

The "spontaneous firing rate" of a neuron refers to ____.

Its rate of producing action potentials even when it is not stimulated

Which terms refers to a chemical that binds to another chemical?

Ligand

Ionotropic effects ____.

May depolarize or hyperpolarize the postsynaptic membrane

Spatial summation refers to ____.

Multiple weak stimulations that occur at the same time

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

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

Nitric Oxide

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

Nitric Oxide

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

Potassium

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

Prolonging the action of acetylcholine at its synapses

Which category of chemicals includes adenosine and several of its derivatives?

Purines

Ionotropic effects are characterized by ____.

Rapid and short-lived effects

Which event is most likely to be dependent on ionotropic effects?

Rapid muscle contraction

Which pattern of post-synaptic excitation will most likely result in an action potential?

Rapid sequence of EPSPs

Temporal summation most likely occurs with ____.

Rapid succession of sub-threshold excitation

The "decision" for a neuron to fire is determined by the ____.

Ratio of EPSPs to IPSPs

The effect of a neurotransmitter on a postsynaptic neuron is determined by the ____.

Receptors on the postsynaptic membrane

To measure temporal summation in single cells, researchers ____.

Record depolarizations of the postsynaptic neuron

What is the proper ordering of a reflex arc?

Sensory neuron, interneuron, motor neuron.

The amino acid tryptophan is the precursor to which neurotransmitter?

Serotonin

In general, a single neuron releases ____ neurotransmitter(s) and can respond to ____ neurotransmitter(s).

Several; many

Hormones exert their effects ____.

Similarly to metabotropic neurotransmitters

Compared to ionotropic effects, metabotropic effects are ____.

Slower and longer lasting

What is the primary difference between temporal summation and spatial summation?

Spatial summation depends on contributions from more than one sensory neuron

Even at rest, most neurons have periodic production of action potentials, known as the ____.

Spontaneous firing rate

Specialized junctions between neurons are called ____.

Synapses

A certain weak stimulus produces no reflexive response, but a rapid repetition of that stimulus may produce such a response. What is this phenomenon called?

Temporal summation

What determines whether a neuron has an action potential?

The combined effects of EPSPs and IPSPs

What is the synaptic cleft?

The gap between the presynaptic neuron and the postsynaptic neuron

What happens when a neurotransmitter is released by a presynaptic cell?

The neurotransmitter passively spreads across the synaptic cleft

What causes an EPSP?

The opening of sodium channels

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

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

The synaptic cleft is very narrow

What do dopamine, norepinephrine, and epinephrine share in common?

They are all synthesized from the same amino acids

Which statement is TRUE of EPSPs?

They decay over time and space

Temporal summation is to ____ as spatial summation is to ____.

Time; location

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 slower than along axons

The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____.

Vesicles

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.