Questão 1
Questão
Which of the following components does NOT dictate the electrical properties of a cell membrane?
Questão 2
Questão
Which of the following ions has a greater concentration inside the cell than outside?
Responda
-
Potassium
-
Sodium
-
Chloride
-
Calcium
Questão 3
Questão
Which of the following ion channels has a single, straightforward function?
Questão 4
Questão
Voltage-gated sodium ion channels are responsible for generating action potentials. They will open when the membrane potential is _________ mV.
Questão 5
Questão
Phenytoin is a common anti-epileptic drug. Which channel does this drug block to prevent seizure activity?
Responda
-
Voltage-gated sodium ion channels
-
Voltage-gated potassium ion channels
-
Voltage-gated calcium ion channels
-
Ligand gated ion channels
Questão 6
Questão
Which of the following are actions of potassium ion channels? (Select all that apply)
Responda
-
Diversifying neuronal electrical properties
-
Diversifying temporal pattern of action potential trains
-
Dictating different responses to synaptic input
-
Intracellular signaling
Questão 7
Questão
What is the primary function of the voltage-gated delayed rectifier potassium ion channel?
Responda
-
Repolarizing the action potential
-
Depolarizing the action potential
-
Setting the resting membrane potential
-
Pace-making
Questão 8
Questão
There are four subtypes of calcium ion channels. Which of the following is NOT a primary function of the T-type channel?
Questão 9
Questão
There are four subtypes of calcium ion channels. Which of the following is a function of the L-type channel?
Questão 10
Questão
The sodium-potassium ATPase pump has three main functions. It exports 3 Na+ for 2 K+ against their concentration gradients. Per action, one net positive charge moves outside of the cell. These maintain the ionic gradients and make the membrane inside the cell ~10-15 mV more negative than the outside. What is the third primary function?
Responda
-
Building the osmotic gradient - inducing osmosis from inside to outside the cell.
-
Building the osmotic gradient - inducing osmosis from outside to inside the cell.
-
Counteracting the osmotic gradient - inhibiting osmosis from inside to outside the cell.
-
Counteracting the osmotic gradient - inhibiting osmosis from outside to inside the cell.
Questão 11
Questão
In some individuals, red blood cells (RBCs) express a high density of Na/K-ATPases to counteract the unusually high permeability of the membrane to Na+. When these RBCs reach and are delayed in the vein of the spleen, what would happen to these RBCs?
Responda
-
They may swell and rupture.
-
They may shrink in volume.
-
They may decrease in membrane potential (membrane inside the cell becomes more negative)
-
They may increase in intracellular potassium.
Questão 12
Questão
If you have a membrane that is impermeable to both sodium and potassium ions, what is the resting membrane potential?
Questão 13
Questão
If you are observing a cell that is only permeable to potassium ions, what would you expect the equilibrium potential to be?
Questão 14
Questão
What would the membrane potential of a cell be if it were only permeable to sodium ions?
Responda
-
60 mV
-
90 mV
-
-90 mV
-
-60 mV
Questão 15
Questão
At resting conditions, we know that the membrane potential of a neuron is about -70 mV. From this value, we can conclude:
Responda
-
PK > PNa at resting conditions
-
PNa > PK at resting conditions
-
PK = PNa at resting conditions
Questão 16
Questão
Which of the following are involved in determining the K+ equilibrium potential of a neuron? (Select all that apply)
Questão 17
Questão
The equilibrium potential will change if...
Responda
-
the ionic gradient changes
-
the resting membrane potential remains constant
-
sodium and potassium are moved in and out of the cell proportionately
Questão 18
Questão
You have a patient in kidney failure. They are not regulating K+ ions in the extracellular fluid. As a result, the extracellular K+ level has increased from 5 mM to 15 mM. How would this affect brain function?
Responda
-
Action potentials will occur more easily
-
Action potentials will not occur as easily
-
There will be no change in action potential generation
Questão 19
Questão
The presence of leak potassium channels, which are always open:
Responda
-
Drives the membrane potential towards the potassium equilibrium potential (-90 mV)
-
Drives the membrane potential towards the potassium equilibrium potential (-70 mV)
-
Drives the membrane potential towards the sodium equilibrium potential (-90 mV)
-
Drives the membrane potential towards the sodium equilibrium potential (60 mV)
Questão 20
Questão
What will happen to the resting membrane potential if we block half of the leak potassium ion channels in the membrane?
Responda
-
It will increase
-
It will decrease
-
It will not change