Firing the Neuron

What is action potential?

a rapid electrical impulse that travels along the axon of a neuron, triggered by a change in membrane potential. It is essential for transmitting signals in the nervous system.

What is resting potential?

The electrical potential of a neuron when it is not actively sending a signal, typically around -70 mV. This state is maintained by ion channels and pumps that regulate the concentration of ions inside and outside the cell.

What causes the opportunity for a change in the neuron’s state?

Gradients (chemical or electrical) between the inside and outside of a neuron.

How does a neuron reach the threshold for excitement?

when sufficient depolarization occurs, typically due to the influx of sodium ions, making the inside of the neuron more positive and allowing action potentials to be generated.

What is depolarization?

A massive, explosive swing in chemical and electrical gradient changing the relative charge of the cell from negative to positive

What is saltatory conduction?

The process by which action potentials jump between nodes of Ranvier along myelinated axons, increasing the speed of neural transmission.

How is the strength of neural connections determined?

The intensity of the action potential, how rapidly the neuron fires in succession.

What is repolarization?

The process by which a neuron returns to its resting membrane potential after depolarization, restoring the negative charge inside the cell.

What is the overshoot?

The result of hyper-polariztion where the neuron goes past the baseline potential of -70 mili volts

What ions play a key role in the production of action potential?

Sodium (Na+) and potassium (K+) ions., as well as chloride (Cl^-) ions Besides ions negatively charged proteins reside inside the neuron as well.

What is intraneural communication?

The process by which a neuron sends signals through itself

How can a gated channel open?

From structure, voltage or chemical changes

What are ligand gated channels?

Channels that open in response to the binding of a chemical messenger, such as a neurotransmitter, allowing ions to flow across the membrane.

What is the sodium potassium pump and why is it important to the neuron?

The sodium-potassium pump is a membrane protein that actively transports sodium ions out of the neuron and potassium ions into the neuron. It is essential for maintaining the resting membrane potential and facilitating action potentials.

What is the purpose of the excitattory gated channel and how does it work?

Excitatory gated channels allow the influx of positively charged ions, such as sodium, leading to depolarization of the neuron and increasing the likelihood of an action potential.

What is gated potential?

Gated potential refers to changes in the membrane potential of a neuron that occur in response to the opening of gated ion channels, which can lead to either depolarization or hyperpolarization depending on the type of ions that flow through.

What is the threshold for entering action potential of a neuron?

The threshold for entering action potential is the critical level of depolarization that must be reached for an action potential to occur, typically around -55 mV. Once this threshold is reached, voltage-gated sodium channels open, leading to a rapid influx of sodium ions and the generation of an action potential.

What is an inhibitory ligand channel in a neuron do?

Inhibitory ligand channels allow the influx of negatively charged ions, such as chloride, or the efflux of positively charged ions, leading to hyperpolarization of the neuron. This decreases the likelihood of an action potential occurring.

What happens during depolarization?

During depolarization, the membrane potential of a neuron becomes less negative, usually due to the influx of sodium ions through voltage-gated sodium channels, moving the membrane potential closer to zero and potentially triggering an action potential.

To fire in rapid sucession, how does a ne3uron return to resting potential quickly?

A neuron quickly returns to resting potential through the process of repolarization, where potassium channels open to allow potassium ions to exit the cell, restoring the negative membrane potential. An shuffles sodium into the cell using the sodium potassium pump.

Once we create action potential, what must happen?

The action potenttial must move along the axon.

how does the action potential move down the axon?

The more negative outside form the action potential causes a chain reaction to move the signal down the axon , this is called propagation. Without mylineated sheafs this process is much slower.