Neuroscience Exam 2 Questions (need to do miniquizzes)

What is the resting membrane potential of a neuron?

-65 mV

In the figure of the action potential below, which number corresponds to the rapid release of K+ ions out of the cell?

4

IPSPs are inhibitory because they result from Cl- ions flowing into the postsynaptic cell.

True

What is the main excitatory neurotransmitter in our nervous system?

Glutamate

Which dose-repose curve below has the lowest potency?

C

A cell that releases a hormone into the bloodstream to act on target tissues is called _______ communication. 

Endocrine

Releasing hormones are produced in the pituitary gland.

False

Which element is an anion in the extracellular or intracellular fluid?

Chloride

The resting membrane potential is

a product of the distribution of ions across the membrane

At the peak of the action potential, the axonal membrane approaches the equilibrium potential for______

Na⁺.

The absolute refractory period refers to the brief period of time

after a neuron has fired an action potential, during which the same neuron cannot fire another action potential.

Postsynaptic potentials are a type of

graded potential.

Neurons process information by integrating (summing algebraically) the postsynaptic potentials through both _______ summation (summing potentials from different locations) and _______ summation (summing potentials across time).

spatial; temporal

The greater the influx of calcium into the presynaptic axon terminal, the greater the

release of neurotransmitter.

Which sequence presents presynaptic events in the correct chronological order?

Action potential reaches axon terminal → calcium ion channels open → exocytosis → diffusion of neurotransmitter

The substance tetrodotoxin (TTX), found in the ovaries of pufferfish, is useful for studying the ionic mechanisms of the action potential because it

selectively blocks sodium channels.

G proteins are able to amplify the message from a single receptor because they

activate second messenger proteins inside the cell.

During the action potential, the neuron cannot be excited by a second stimulus; it is _______. For a few milliseconds afterward, the hyperpolarized neuron is _______, requiring a stronger stimulation than usual in order to fire.

absolutely refractory; relatively refractory

_______ synapses work with practically no time delay, whereas _______ synapses have a delay on the order of about a millisecond.

Electrical; chemical

Inside the nerve cell there is a high concentration of _______ ions, while outside the cell there is a high concentration of _______ ions.

potassium; sodium

_______ are specialized presynaptic membrane receptors that remove molecules of transmitter from a synapse.

Transporters

_______ conduction of the action potential along the nodes of _______ between myelin sheaths speeds propagation down the axon.

Saltatory; Ranvier

A _______ receptor changes its shape to open an ion channel, and a _______ receptor alters chemical reactions within the target cell.

ionotropic; metabotropic

Which statement best illustrates the versatility of neurotransmitters?

All of the above

Which compound is not part of the amine subtype of neurotransmitters?

Glycine

If a newly developed drug is found to bind to serotonin receptors and activate them, the drug is classified as a(n)

agonist.

Drugs that block GABA receptors might lead to (chose the best response given what you know about the general function of GABA)

seizures

A wider therapeutic window for a drug usually is associated with the drug

having a wider margin of safety

Which of the following events would cause a down-regulation of receptor sites?

A large number of agonist molecules are available to the receptors over a period of time.

An exogenous agonist

has the same effect on a channel as the native neurotransmitter.

The dose at which a drug has a half-maximal response is termed the

ED50

Neurotransmitters that are co-localized means that they

are released by the same neuron.

The terms "nicotinic" and "muscarinic" refer to families of _______ receptors.

acetylcholine

Refer to the graph.

What does the vertical dashed line on the graph represent?

ED₅₀

A cell that releases a hormone that affects the cell next to it is engaged in _______ communication.

paracrine

Neurosecretory cells of the hypothalamus release _______ into the bloodstream.

hormones

Peptide hormone effects are often mediated by the second messenger ________

cyclic AMP.

In general, steroid hormones from peripheral endocrine organs _______ the release of hormones from the pituitary through the process of _______ feedback.

inhibit; negative

_______ hormones affect the secretion of other endocrine glands.

Tropic

The technique used for identifying the location of a hormone receptor using antibodies to that receptor is

immunocytochemistry.

Which hormone is responsible for the contractions of the uterus during childbirth?

Oxytocin

Which substance acts by passing through plasma membranes to enter cells to couple with receptors inside the cell then interact with DNA, thereby altering gene expression?

Steroid hormones

The adrenal medulla releases its hormones in response to

sympathetic nervous activity.

Referring to the figure, if TSH is high and thyroid hormones are high, where is the dysfunction in the feedback loop?

feedback to the anterior pituitary or the hypothalamus is not functioning

Ions are atoms or molecules that carry an electric charge due to the gain or loss of

electrons.

Action potentials generally are not transmitted along dendrites because they have

few voltage-gated Na⁺ channels.

In people with _______, conduction of action potentials is disrupted because the immune system produces antibodies that attack myelin.

multiple sclerosis

The _________ is the site at which the action potential is initiated.

axon hillock

The overall amplitude of the action potential is about

100 mV.

Most IPSPs are attributable to the

opening of chloride channels.

Whether a synapse is excitatory or inhibitory is determined by the

type of transmitter released by the presynaptic neuron and the receptor to which that transmitter binds on the postsynaptic neuron.

A ligand is a

molecule that binds to receptor proteins.

Curare and bungarotoxin are similar in that they both

act as acetylcholine receptor antagonists.

In the knee-jerk reflex, the total time between the stimulus and the initiation of the response is about _______ ms.

40

1/1

The amount of transmitter released at an axon terminal is proportional to the amount of _________ that enters the axon terminal.

calcium

The term "kindling" refers to

the experimental induction of seizures using subthreshold stimuli

In optogenetics, researchers use _______ light to stimulate _______.

blue; channelrhodopsin

Event-related potentials are particularly useful for diagnosing problems with ______

hearing

A fast _______ receptor changes its shape to open an ion channel, and a slow _______ receptor alters chemical reactions within the target cell.

ionotropic; metabotropic

At present, at least ________ different types of receptors for dopamine have been identified (with two additional possibilities).

 

five

Damage to the locus coeruleus would result in decreased production of

norepinephrine.

Drugs that block GABA receptors tend to cause

seizures.

The endogenous opiates belong to the _____

family of neurotransmitters.

peptide

A drug that affects the function of a receptor without impeding the access of neurotransmitter molecules to their binding sites on the receptor is a

noncompetitive ligand.

The affinities of drugs are expressed in units of concentration: the higher the affinity, the __________ the concentration.

lower

What is the process that is being depicted?

Down regulation

Historically, some native hunters have been known to immobilize prey using chemicals isolated from plants. Which substance would work best for this purpose?

Curare

The mood-stabilizing drug lithium acts by

altering second-messenger systems.

Which substance competes with the neuromodulator adenosine? And where on this figure would it act?

Caffeine; B

The antipsychotic drug haloperidol is particularly selective for dopamine _______ receptors.

D₂

Benzodiazepines, such as diazepam or other anxiolytics, appear to modulate the activity of the neurotransmitter

GABA.

What is the main active compound extracted from poppies?

Morphine

Cocaine was initially used as a(n)

local anesthetic.

Stimulation of serotonergic receptors in the visual cortex by which drug causes hallucinations?

LSD

The active ingredient in marijuana, THC, exerts its effects on the brain through interactions with __________ receptors.

cannabinoid

Which statement about substance abuse treatments is true?

We may be able to disrupt the connection between drug cues and the rewards of a drug.

The ________ model of drug abuse considers abuse to be a consequence of a desire to avoid withdrawal symptoms.

physical dependence

A common feature of addictive drugs appears to be that they cause the release of dopamine in the

nucleus accumbens

If a hormone-secreting cell is affected by the hormone that it synthesizes, the hormone is said to act in a(n) _______ fashion.

autocrine

Compared to neurotransmitters, hormone effects are generally

more widespread in the body.

Which of the following is not a steroid hormone?

Growth hormone

A newly developed drug that blocks cell membrane receptors would likely have the greatest effect on

vasopressin

The more rapid effects of estrogen on neuronal membranes is an example of

nongenomic steroid action.

Hormones that induce cells to release their hormones are collectively known as _________ hormones.

tropic

If a person does not release sufficient amounts of oxytocin and vasopressin, the sources of the problem are likely to be found in the _______ or the _______.

hypothalamus; posterior pituitary

The symptoms of "jet lag" experienced following a few hours of eastward travel is caused by a(n)

exposure to sunlight at the end of one's melatonin secretion phase.

Growth hormone secretion can be prompted by the release of the hormone _______ from the stomach.

ghrelin

The main role of FSH is to

stimulate follicle development in the ovaries.

Men rooting for a sports team will produce more _______ if their team wins.

testosterone

You feel excited by a peer at a party. Primping your hair, walking up to them, smiling, and striking up a conversation are all behaviors that are an example of a(n) _________ link.

endocrine-to-neural