Xx Flashcards
(20 cards)
What is the resting membrane potential?
The resting membrane potential is the electrical potential difference across the membrane of a cell when it is not actively sending signals.
True or False: The resting membrane potential is typically positive.
False
Fill in the blank: The typical resting membrane potential of a neuron is around ____ mV.
-70 mV
What primarily contributes to the resting membrane potential?
The distribution of ions, especially sodium (Na+), potassium (K+), chloride (Cl-), and negatively charged proteins.
Which ion is most permeable at rest in neurons?
Potassium (K+)
Multiple Choice: What is the role of the sodium-potassium pump in maintaining resting membrane potential? A) It increases Na+ concentration inside the cell B) It decreases K+ concentration outside the cell C) It pumps 3 Na+ out and 2 K+ in D) It has no effect
C) It pumps 3 Na+ out and 2 K+ in
What happens to the resting membrane potential if the permeability to potassium increases?
The resting membrane potential becomes more negative (hyperpolarizes).
True or False: Resting membrane potential can change depending on external conditions.
True
What is the significance of the resting membrane potential in neurons?
It sets the stage for action potentials and the transmission of electrical signals.
Fill in the blank: The resting membrane potential is mainly determined by the ____ gradient of potassium ions.
concentration
Which ion has a higher concentration inside the cell at resting potential?
Potassium (K+)
Multiple Choice: Which of the following factors does NOT affect the resting membrane potential? A) Ion concentrations B) Temperature C) Membrane thickness D) Ion permeability
C) Membrane thickness
What role do negatively charged proteins play in resting membrane potential?
They contribute to the negative charge inside the cell.
True or False: The resting membrane potential is the same in all cell types.
False
What is the Nernst equation used for?
It calculates the equilibrium potential for a specific ion based on its concentration gradient.
Fill in the blank: The resting membrane potential is generally more negative than the equilibrium potential of ____.
sodium (Na+)
What is one effect of depolarization on the resting membrane potential?
It makes the inside of the cell less negative (closer to zero).
Multiple Choice: Which of the following conditions would likely lead to depolarization? A) Increased K+ permeability B) Increased Na+ permeability C) Decreased Na+ permeability D) No change in ion permeability
B) Increased Na+ permeability
How does hyperpolarization affect neuronal excitability?
It decreases neuronal excitability, making it less likely to fire an action potential.
What is the typical range of resting membrane potential for cardiac muscle cells?
-80 to -90 mV
