How neurons transmit electro chemical impluses to the brain?
Neurons transmit electrochemical impulses, also known as action potentials, to the brain through a process called neural communication. This process involves the coordinated activity of various cellular components and neurotransmitters. Here's a simplified explanation of how neurons transmit electrochemical impulses:
1. Resting Potential:
Each neuron maintains a resting potential, which is a stable electrical charge difference across its cell membrane. This potential difference is due to the unequal distribution of ions (such as sodium, potassium, and chloride) inside and outside the neuron.
2. Depolarization:
When a neuron receives a stimulus (such as a neurotransmitter released from another neuron), it causes the cell membrane to become more permeable to sodium ions. This influx of sodium ions leads to a change in the electrical charge across the membrane, resulting in depolarization.
3. Action Potential Generation:
If the depolarization reaches a certain threshold, it triggers an action potential. This is a self-propagating electrical signal that travels along the neuron's axon, the long, slender projection of the neuron. During an action potential, the sodium channels in the membrane open fully, causing an even greater influx of sodium ions and reversing the electrical charge.
4. Repolarization:
Following depolarization, the neuron's membrane becomes less permeable to sodium ions and more permeable to potassium ions. Potassium ions then flow out of the neuron, causing the membrane potential to return to its resting state. This process is called repolarization.
5. Hyperpolarization:
Immediately after repolarization, the membrane potential briefly becomes more negative than the resting potential. This is known as hyperpolarization. During this phase, the neuron is less excitable and less likely to generate another action potential.
6. Refractory Periods:
After an action potential, the neuron enters a refractory period. The absolute refractory period is a brief period during which the neuron cannot generate another action potential, regardless of the strength of the stimulus. This is followed by a relative refractory period, during which a stronger-than-normal stimulus is required to generate an action potential.
7. Neurotransmitter Release:
When an action potential reaches the end of the axon (axon terminal), it triggers the release of neurotransmitters. These chemical messengers cross the synaptic gap (the space between neurons) and bind to receptors on the dendrites (receptive structures) of adjacent neurons.
8. Postsynaptic Potential:
The binding of neurotransmitters to receptors on the postsynaptic neuron can cause either depolarization (excitatory postsynaptic potential, or EPSP) or hyperpolarization (inhibitory postsynaptic potential, or IPSP) of the membrane potential. If the depolarization reaches the threshold, it triggers an action potential in the postsynaptic neuron, continuing the transmission of the electrochemical impulse.
This process of electrochemical impulse transmission allows neurons to communicate with each other, process information, and control various bodily functions. The brain integrates these impulses from numerous neurons to generate thoughts, emotions, behaviors, and perceptions.