Operation, Köttbullar och Ritning
Kategori: -Allmänt, Gästbloggare, Hjälp, Q & A
1. When a stimuli reaches a neuron cell it stimulates the Na+ gates to open so Na+ can enter. More and more Na+ is flooding in, making the outside less positive and the inside more positive.
2. When the cell are filled up with too much positive Na the Na+ gate closes and instead the K+ gate open to release K out of the cell to stabilize the two poles as the inside of the cell now is getting less negative.
3. The Na/K-pumps are restoring the amount of placement of the K and Na ions. This turns the body to its resting membrane potential. It is releasing 3 sodium ions and in exchange let in 2 potassium ions.
4. This movement of ions is a signal of the nervous system; once it has been done in one area of the membrane it is doing the same in the next area of the membrane- like a wave in the ocean. It is the strength of the “wave” that is carrying the information-code. The sodium channels in the next area are opening to let sodium in to stimulate a new “round”/”turn” of transmission.
5. The signal will eventually reach a synapses at the end of the neuron, and this is where the signal in is transferred to the next neurons.
6. When the impulse reaches the synapse it is, to begin with, triggering Ca channels to open to let in Ca+(`2) into the neuron from the cleft. This in turn triggers the release of neurotransmitter from vehicles. It is the frequency of impulse to the synapse which determines the message in the neurotransmitter.
7. The neurotransmitter binds to the receptors which are connected to sodium channels. The sodium channels open after the receptor has been stimulated by the neurotransmitter.
8. Sodium ions can now flow into the next neuron through the sodium channels and an impulse is created in the next neuron.
9. When the positive sodium enters the postsynaptic cell and the charge change, it makes the K+ channels to open so that K+ can exit the postsynaptic cell. (Or/and Cl- can enter it, depending on if the Cl channel open).
10. Enzymes are used at the receiving end of the new neuron to destroy the neurotransmitter which leads to closure of sodium pumps. Or the neurotransmitter can be sent back to the presynaptic cell or used for other important task in the nearby area.