How the neuron allow impulse transmission?

The process of information transmission in neurons, often referred to as impulse transmission, involves several key steps and mechanisms within the neuron. Here is an overview of how neurons transmit impulses:

Resting Membrane Potential:

- Neurons maintain a resting membrane potential, which is a difference in electrical charge across their cell membrane. This potential is established and maintained by ion concentration gradients and specific ion channels in the membrane.

Action Potential Generation:

1. Depolarization: When a stimulus is strong enough to overcome the neuron's threshold potential, the neuron undergoes depolarization. During this phase, the membrane potential rapidly becomes less negative (i.e., more positive) due to the opening of voltage-gated sodium (Na+) channels. Sodium ions rush into the neuron, further depolarizing the membrane.

2. Action Potential: The depolarization reaches a peak, triggering an action potential. During this phase, the membrane potential rapidly reverses, becoming more positive than the resting potential. The influx of sodium ions causes the membrane to become highly permeable to sodium.

3. Repolarization: After the peak of the action potential, the membrane potential begins to repolarize, returning towards its resting potential. Voltage-gated potassium (K+) channels open, allowing potassium ions to flow out of the neuron, repolarizing the membrane.

Refractory Periods:

- Absolute Refractory Period: During the absolute refractory period, a neuron is completely unresponsive to further stimuli. The sodium channels are inactivated, and the membrane cannot generate another action potential.

- Relative Refractory Period: In this phase, the neuron is less responsive to stimuli compared to its resting state. Some sodium channels are still inactivated, but the membrane is more likely to generate an action potential if a strong enough stimulus is received.

Propagation of the Action Potential:

- The action potential propagates along the axon, away from the neuron's cell body. The depolarization wave causes voltage-gated sodium channels in adjacent sections of the membrane to open, leading to the sequential generation of action potentials.

Saltatory Conduction:

- In myelinated neurons, where the axon is covered with myelin sheaths, the action potentials appear to "jump" from one node of Ranvier to another. This saltatory conduction speeds up the transmission of action potentials over long distances.

At the synapse (junction between two neurons), the action potential triggers the release of neurotransmitters into the synaptic cleft, allowing the transmission of signals to neighboring neurons or target cells, thus propagating the information throughout the nervous system.

The orchestrated interplay of ion channels, membrane potential changes, and neurotransmitter release enables neurons to transmit electrical impulses quickly, efficiently, and in a highly organized manner, supporting communication within the complex neural networks of the brain and body.