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
