Neural Conduction and Synaptic Transmission Flashcards
Action potentials are produced by the
Select one:
a. opening of voltage-activated sodium channels.
b. closing of voltage-activated calcium channels.
c. closing of ligand-activated potassium channels.
d. closing of ligand-activated chloride channels.
e. opening of ligand-activated potassium channels.
a. opening of voltage-activated sodium channels.
Contributing to the unequal distribution of ions on either side of a resting neural membrane
Select one:
a. is random ion movement.
b. are electrostatic gradients.
c. are sodium-potassium pumps.
d. both A and B
e. both B and C
c. are sodium-potassium pumps.
Dopamine is not an effective treatment for Parkinson’s disease because
Select one:
a. Parkinson’s disease is a cholinergic dysfunction.
b. dopamine does not readily penetrate the blood-brain barrier.
c. Parkinson’s disease is a noradrenergic dysfunction.
d. d’Orta is the treatment of choice.
e. dopaminergic neurons are restricted to the PNS.
b. dopamine does not readily penetrate the blood-brain barrier.
Drugs that facilitate the activity of the synapses of a particular neurotransmitter are said to be \_\_\_\_\_\_\_\_\_\_ of that neurotransmitter. Select one: a. endorphins b. antagonists c. autoreceptors d. facilitators e. agonists
e. agonists
IPSP is to EPSP as
Select one:
a. cable properties are to noncable properties.
b. excitatory is to inhibitory.
c. graded is to nongraded.
d. hyperpolarization is to depolarization.
e. presynaptic is to postsynaptic.
d. hyperpolarization is to depolarization.
Na+ ions are encouraged to move into neurons by Select one: a. the sodium-potassium pump. b. nonrandom assignment. c. selective ion channels. d. nonrandom movement. e. electrostatic pressure.
e. electrostatic pressure.
Some of the morphine-like substances that occur naturally in the brain are Select one: a. autoreceptors. b. false transmitters. c. benzodiazepines. d. exogenous. e. endorphins.
e. endorphins.
The wave of absolute refractoriness that follows an action potential
Select one:
a. produces a second, negative action potential.
b. produces saltatory conduction.
c. increases the firing rate.
d. increases the speed of axonal transmission.
e. keeps the action potential from spreading actively back along an axon towards the cell body.
e. keeps the action potential from spreading actively back along an axon towards the cell body.
When a small-molecule neurotransmitter molecule binds to an ionotropic receptor, the
Select one:
a. EPSP gradually increases.
b. cell fires.
c. cell stops firing.
d. associated ion channel opens or closes.
e. ligand is deactivated.
d. associated ion channel opens or closes.
Roberto Garcia d’Orta referred to himself as “a great lizard frozen in a dark, cold, strange world.” He suffered from ________
Parkinson’s disease
Substatia nigra produces a chemical called _______
Dopamine
The difference in electrical charge between the inside and the outside of a cell is called the _______
Membrane potential
The _______ is about -70mV
Resting potential
_______ are the positively and negatively charged particles of salts inside the neuron
Ions
Two factors pressure Na+ ions to enter resting neurons: random _______ and electrostatic pressure
Motion
When a neuron is in a resting state, there is a greater concentration of ______ ions outside the neuron
Sodium
The ______ channels are open in a resting neuron
Potassium
Ions pass through neural membranes via specialised pores called ______
Ion channels
The firing of neurons releases chemicals at their button terminals called _______
Neurotransmitters
Neurotransmitters typically have one of two effects on postsynaptic neurons: they either depolarise them or ______ them
Hyperpolarise
When neurons add or combine a number of individual signals into one overall signal, this is called _______
Integration
_______ is the sum of the postsynaptic potentials produced in rapid succession at the same synapse to form a greater signal
Temporal summation
An action potential is elicited when the depolarisation of the neuron reaches the _______
Threshold of excitation
Unlike the postsynaptic potentials, which are graded, action potentials are _______ responses
All-or-none
Neurons integrate postsynaptic potentials in two ways: through spatial summation and through _______ summation
Temporal
How does axonal conduction differ to the conduction of EPSPs and IPSPs ?
Action potential do not grow weaker as they travel along the axonal membrane
Action potentials are conducted more slowly that postsynaptic potentials
What are the four classes of small-molecule neurotransmitters?
Amino acids
Monoamines
Acetylcholine
Unconventional neurotransmitters
What is the class of large-molecule neurotransmitters called?
Neuropeptides
Which class of neurotransmitter does dopamine belong to?
Monoamine
Which class of neurotransmitter does carbon monoxide belong to?
Unconventional neurotransmitter
Which class of neurotransmitter does glutamate belong to?
Amino acids
Which class of neurotransmitter does GABA belong to?
Amino acids
Which class of neurotransmitter does serotonin belong to?
Monoamines
Which class of neurotransmitter does epinephrine belong to?
Monoamines
What are the five neuropeptides?
Pituitary peptides Hypothalamic peptides Brain-gut peptides Opioid peptides Miscellaneous peptides
What is an absolute refractory period?
a brief period (typically 1 to 2 milliseconds) after the initiation of an action potential during which it is impossible to elicit another action potential in the same neuron
What is acetylcholine?
a neurotransmitter that is created by the addition of an acetyl group to a choline molecule
What is acetylcholinesterase?
the enzyme that breaks down the neurotransmitter acetylcholine
What is an action potential?
a massive momentary reversal of a neuron’s membrane potential from about -70mV to about +50mV
What is an agonist?
drugs that facilitate the effects of a particular neurotransmitter
What are all-or-nothing responses?
responses that are not graded; they either occur to their full extent or no not occur at all
What are amino acid neurotransmitters?
a class of small-molecule neurotransmitters, which includes the amino acids glutamate, aspartate, glycine and GABA
What is anandamide?
the first endogenous endocannabinoid to be discovered and characterised
What are antagonists?
drugs that inhibit the effects of a particular neurotransmitter
What is antidromic conduction?
axonal conduction opposite to the normal direction; conduction from axon terminals back towards the cell body
What is aspartate?
an amino acid neurotransmitter