15 Questions
What is the typical value for resting membrane potential in nerve fibers?
-70 mV
What is the main cause of unequal distribution of ions across the cell membrane during rest?
Selective membrane permeability to K+ ions
What is the role of the Na+/K+-ATPase pump in maintaining resting membrane potential?
It pumps 3 Na+ ions into the cell
What type of ion channels are stimulated by changes in voltage?
Voltage-gated channels
What is the typical value for resting membrane potential in skeletal and cardiac muscle fibers?
-90 mV
Explain the role of the Na+/K+-ATPase pump in maintaining the resting membrane potential.
The Na+/K+-ATPase pump pumps 3 Na+ out of the cell and 2 K+ ions into the cell, contributing to the unequal distribution of ions across the cell membrane and helping to maintain the resting membrane potential.
How does the unequal distribution of ions across the cell membrane contribute to the resting membrane potential?
The unequal distribution of ions, with the membrane being more permeable to potassium ions (K+) than sodium ions (Na+), leads to more positive ions being pumped outside than inside, resulting in negativity inside and positivity outside the cell.
What is the significance of the intracellular non-movable negatively charged proteins in maintaining the resting membrane potential?
The non-movable negatively charged proteins on the inner surface of the cell membrane contribute to the negativity inside the cell, as they cannot move due to their large size.
Describe the role of leak channels in the behavior of nerve cell membranes.
Leak channels play a role in maintaining the resting membrane potential by allowing a slow leakage of ions, helping to stabilize the membrane potential.
How do voltage-gated channels contribute to the electrical events in nerves?
Voltage-gated channels are stimulated by changes in voltage and play a key role in generating and propagating action potentials in nerve cells.
What is the typical value for resting membrane potential in nerve fibers?
-70 mV
What is the typical value for resting membrane potential in skeletal and cardiac muscle fibers?
-90 mV
What is the main cause of the unequal distribution of ions across the cell membrane during rest?
Unequal distribution of ions across cell membrane in extracellular fluid and cytoplasm due to selective membrane permeability, Na+/K+-ATPase pump, and intracellular non-movable negatively charged proteins.
What is the role of the Na+/K+-ATPase pump in maintaining the resting membrane potential?
The Na+/K+-ATPase pump pumps 3 Na+ out of the cell and 2 K+ ions into the cell, contributing to the negativity inside and positivity outside the cell, thus maintaining the resting membrane potential.
How do leak channels and gated channels contribute to the behavior of nerve cell membranes?
Leak channels allow the passive movement of ions, while gated channels, including voltage-gated and ligand-gated channels, are stimulated by changes in voltage or attachment of a substance, respectively, contributing to the electrical events in nerves.
Test your knowledge of the resting membrane potential, which is the potential difference between the inner and outer surfaces of the cell membrane during rest. Explore the values for nerve fibers, skeletal and cardiac muscle fibers, as well as the causes such as unequal distribution of ions and selective membrane permeability.
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