Definition of Gradient: A gradient exists when there is a disparity between two levels or points, which indicates a difference or change in a particular variable.
Degree of Disparity: The greater the difference between the two points, the stronger the gradient. Comparing an incline, such as a hill versus a mountain, illustrates varying gradients.
Also known as electrostatic pressure or electrostatic force.
Charged particles, like ions, experience forces due to their electrical charges: like charges repel each other, while opposite charges attract.
Behavior of Charges: Opposite charges line up along membranes, creating regions of high and low potential, impacting ion movement.
Defined by the movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached.
Example: In a beaker with colored fluids, molecules will naturally move to equalize concentration, yielding a mixed color (e.g., green).
This movement occurs in situ, meaning in the natural, undisturbed condition.
Ion Movement: Understanding gradients is crucial to understanding how ions such as sodium and potassium move during an action potential.
Axon Structure: Key areas include the axon hillock and the initial segment, where action potentials are measured and start.
Charged Particles: Positive charges moving into the axon hillock influence other ions, particularly affecting potassium (K+) and sodium (Na+) ions.
Anions: Large negatively charged molecules trapped in the axon, contributing to the negative internal charge.
Cations: Potassium (K+) and sodium (Na+) are positive ions that respond to the gradients, moving according to the electrical and concentration gradients.
When a wave of positive charges reaches the axon hillock, potassium ions may exit the axon or move along it due to repulsive forces.
This creates a chain reaction, as movements influence neighboring ions, ultimately depolarizing sections of the axon and propagating the action potential along the length of the axon.
Resting Membrane Potential: The potential difference between the extracellular and intracellular environments is observed, typically around -70 mV for neurons.
Events of hyperpolarization (more negative) or depolarization (less negative) occur depending on ion movements.
Inhibitory Postsynaptic Potential: Negative charges entering the axon hillock can hyperpolarize the initial segment, blocking action potential formation.
Excitatory Postsynaptic Potential: Positive influences on the axon hillock can lead to depolarization, increasing the potential for action potentials.
This refers to the phase where changes in membrane potential occur due to the influence of charges in the axon hillock and initial segment.
The magnitude of depolarization varies; however, a certain threshold is required for an action potential to occur, which is probabilistic in nature.
The initial segment is critical since it is where action potentials are generated and will propagate down the axon rapidly, following an all-or-none principle.
axon podcats part 1
Definition of Gradient: A gradient exists when there is a disparity between two levels or points, which indicates a difference or change in a particular variable.
Degree of Disparity: The greater the difference between the two points, the stronger the gradient. Comparing an incline, such as a hill versus a mountain, illustrates varying gradients.
Also known as electrostatic pressure or electrostatic force.
Charged particles, like ions, experience forces due to their electrical charges: like charges repel each other, while opposite charges attract.
Behavior of Charges: Opposite charges line up along membranes, creating regions of high and low potential, impacting ion movement.
Defined by the movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached.
Example: In a beaker with colored fluids, molecules will naturally move to equalize concentration, yielding a mixed color (e.g., green).
This movement occurs in situ, meaning in the natural, undisturbed condition.
Ion Movement: Understanding gradients is crucial to understanding how ions such as sodium and potassium move during an action potential.
Axon Structure: Key areas include the axon hillock and the initial segment, where action potentials are measured and start.
Charged Particles: Positive charges moving into the axon hillock influence other ions, particularly affecting potassium (K+) and sodium (Na+) ions.
Anions: Large negatively charged molecules trapped in the axon, contributing to the negative internal charge.
Cations: Potassium (K+) and sodium (Na+) are positive ions that respond to the gradients, moving according to the electrical and concentration gradients.
When a wave of positive charges reaches the axon hillock, potassium ions may exit the axon or move along it due to repulsive forces.
This creates a chain reaction, as movements influence neighboring ions, ultimately depolarizing sections of the axon and propagating the action potential along the length of the axon.
Resting Membrane Potential: The potential difference between the extracellular and intracellular environments is observed, typically around -70 mV for neurons.
Events of hyperpolarization (more negative) or depolarization (less negative) occur depending on ion movements.
Inhibitory Postsynaptic Potential: Negative charges entering the axon hillock can hyperpolarize the initial segment, blocking action potential formation.
Excitatory Postsynaptic Potential: Positive influences on the axon hillock can lead to depolarization, increasing the potential for action potentials.
This refers to the phase where changes in membrane potential occur due to the influence of charges in the axon hillock and initial segment.
The magnitude of depolarization varies; however, a certain threshold is required for an action potential to occur, which is probabilistic in nature.
The initial segment is critical since it is where action potentials are generated and will propagate down the axon rapidly, following an all-or-none principle.