2.Resting Potential of Neurons Flashcards
What is the resting potential of a neuron?
The electrical charge difference across the neuronal membrane, typically ranging from –50 to –80 mV.
What is neuronal polarity?
A state where the inside of the neuron is more negative than the outside.
What ions are primarily concentrated inside the neuron?
Anions (negatively charged, such as protein anions) and K+ ions (potassium).
What ions are primarily concentrated outside the neuron?
Cations, particularly Na+ ions (sodium).
What role do ion channels play in maintaining the resting potential?
They selectively allow K+ ions to move across the membrane while blocking Na+ ions.
How does diffusion affect potassium ions (K+)?
K+ ions move down their concentration gradient, from higher concentration inside the neuron to lower concentration outside.
What is electrostatic pressure in the context of neurons?
A force that attracts positively charged K+ ions back into the negatively charged neuron interior.
What is the sodium-potassium pump, and how does it function?
A pump that actively moves 3 Na+ ions out and 2 K+ ions in, using energy to maintain ion gradients.
Why is the sodium-potassium pump essential?
It helps maintain the ion concentration necessary for the resting potential and neuronal activity.
What is equilibrium potential?
The balance point where K+ diffusion out of the cell is countered by electrostatic pressure pulling K+ back in.
What is the typical value of the resting potential, and what causes it?
Around –65 mV, caused by the balance of forces acting on ions like K+.
Why is the resting potential critical for neurons?
It prepares neurons to respond to stimuli by generating electrical signals.
