Midterm #2

The concentration of sodium ions is greater in the extracellular space than in the intracellular space

True

The resting potential is about -70mV and cannot vary

False

Which of the following ions are not involved in the maintenance of the resting potential?

Calcium ions

Conduction velocity along axons is faster in small, unmyelinated axons than in thick myelinated ones

False

Hyperpolarization

Depolarization

Depolarization

is due to an influx of sodium ions through sodium channels

Hyperpolarization

is due to an efflux of potassium ions, making the extracellular side of the membrane more positive.

Hyperpolarization can also be produced ny an influx of

Cl-

Action potentials generally are not propagated along dendrites because they have

few voltage-gated ion channels

For an EPSP to cause another action potential, the stimulation must reach the _____, which is (are) rich in voltage-sensitive ion channels.

initial segment (axon hillock)

Otto Loewi

discovered that chemicals carry the information from one cell to another across the synapse

Where on the neuron do EPSP and IPSP happen

Dendrite

Inhibitory postsynaptic potentials (IPSPs)

Hyperpolarization, decrease probability of action potentials, opening of chloride channels

Excitatory postsynaptic potentials (EPSPs)

Depolarization, increase probability of action potentials, opening of sodium channels,

Reuptake of a neurotransmitter is accomplished by _____

The presynaptic movement

The study of the effects of drugs on the function of the nervous system is

psychopharmacology

The NMDA receptor is a type of receptor for the neurotransmitter

glutamate

Endocannabinoids

Lipid neurotransmitters that inhibit the release of glutamate and GABA amino acids so they decrease neuronal inhibition in the case of GABA receptors and excitation in the case of glutamate receptors

Glutamate

excitatory small molecule transmitter

Norephinephirine, Serotonine and Glutamate are all examples of:

Small-molecule neurotransmitters

GABA is considered to be part of the Small-Molecule Transmitters

True

Which activating system is most often affected by addictive drugs

Dopaminergic System

The excitatory effect of a neurotransmitter is caused by

The nature of the receptor with which it interacts

Neurotransmitter release depends on an influx of _____ ions into the presynaptic terminal

Ca²⁺

In the mammalian brain, the major inhibitory neurotransmitter is

GABA

Type of receptors that may have amplifying and/or second messenger effects

Metabotrobic receptors

Ketamine acts by blocking ___

NMDA receptors

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

GABA

LSD appears to exert its effects through its interactions with receptors for the neurotransmitter

serotonin

The main active ingredient in marijuana is

THC

One perspective on drug addiction proposes that a feature shared by all habit-forming drugs is that they

have strong rewarding properties

Drugs of abuse usually increase levels of _____ neurotransmitter in the central nervous system.

dopamine

People who take a drug for a period of time may come to experience an decreased effect of the drug even with no change in the dosage. This is an example of

tolerance

Under resting conditions, NMDA receptors are unable to respond due to the presence of _______ in their central channels.

Mg²⁺ ions

Agonist is to antagonist as

accelerate is to brake