34 Questions
What is the primary function of the sodium-potassium pump in a neuron?
To maintain the resting membrane potential
What is the main problem that neurons solve using electrical signals?
Conducting information over a long distance
What determines the distribution of ions inside and outside of a neuron at rest?
Electrostatic pressure and diffusion
What is the role of potassium channels in the resting membrane potential?
To allow the efflux of potassium ions
What is the resulting effect of electrochemical forces on the neural membrane?
An electrochemical gradient
What is the primary carrier of electrical charge in the cytosol of the axon?
Electrically charged atoms → ions
What is the main component of the fluid inside cytosol and extracellular fluid?
Water (H₂O)
What type of bond is formed between hydrogen and oxygen atoms in a water molecule?
Covalent bond
What is the term for ions with a positive charge?
Cations
What is the function of membrane proteins in the phospholipid bilayer?
To assemble into pores and ion channels
What is the term for molecules that are attracted to water?
Hydrophilic
What is the energy source utilized by ion pumps to transport ions across the bilayer?
ATP breakdown
What is the ratio of K⁺ to A⁻ when the microelectrode records no potential difference (Vm=0)?
1:1
What happens to the inside of the membrane when potassium ions (K⁺) move out of the cell?
It becomes more negatively charged
What is the equilibrium potential of potassium ions (K⁺) approximately equal to?
-80mV
What is the primary reason for the net movement of ions across the membrane?
The difference between the membrane potential and the equilibrium potential
What is the result of a small change in ionic concentrations on the membrane potential?
A large change in membrane potential
What is the term for the ability of the membrane to store electrical charge?
Capacitance
What is a characteristic of K⁺ channels?
They are selectively permeable to K⁺
What is required for a net movement of ions across the membrane through open channels?
Both open channels and a concentration gradient
What is the result of diffusion in a solution?
Particles are distributed evenly throughout the solution
What is the driving force behind the movement of ions from regions of high concentration to low concentration?
Diffusion
What is the term for the difference in concentration of ions between two regions?
Concentration gradient
What can induce a net flow of ions in a solution?
Electric fields
What is the ionic driving force for a particular ion?
Vm - Eion
What is the purpose of the ion pumps in the neuronal membrane?
To transport ions across the membrane against their concentration gradient
What would happen to the membrane potential if the extracellular K+ concentration increases?
The membrane potential would become less negative
What is the Goldman equation used for?
To calculate the resting membrane potential
What is the role of the sodium-potassium pump in neuronal signaling?
To transport Na+ and Ca2+ ions out of the neuron
What is the effect of a mutation in a specific K+ channel on the neuronal function?
It can lead to inherited neurological disorders
What is the role of the blood-brain barrier in regulating the concentration of K+ ions?
It helps to regulate the concentration of K+ ions in the extracellular space
What is the function of the pore-loop in potassium channels?
It contributes to the selective filter that makes the channel permeable mostly to K+
What is the resting membrane potential close to?
The equilibrium potential for K+
What is the consequence of the differential concentrations of ions inside and outside the neuron and the semipermeable nature of the membrane?
The resting membrane potential
Test your knowledge of the neural membrane, ion channels, and the action potential from Lecture 4 of PSY1BNA at La Trobe University. Covers the role of ion channels in generating the action potential, action potential conduction, and neural integration. Also, explores neurotransmitter synthesis and synaptic transmission.
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