24/7 writing help on your phone
Save to my list
Remove from my list
The process of neurons communicating is complex and is composed of a few steps. Simply the process is the generation of an electrical signal (action potential), the conversion of that electrical signal to a chemical one, and the transmission of that signal between two neurons. This process then repeats itself, over and over, to allow signals to travel all over the body and facilitate movement. I’ll use this assignment to explain this process in greater detail. The generation of action potential is something that seems simple but is actually a pretty complex process.
It all deals with the depolarization and hyper-polarization of the membrane.
In order for the generation of action potential to begin the membrane must depolarize to allow the action potential to begin to generate, starting at the threshold of excitation, where the action potential begins to generate. A complex process then begins; first, sodium channels open allowing more sodium to enter the cell.
This is followed by potassium channels opening and potassium ions leaving the cell.
Then, in whats described as the peak of action potential generation, the sodium channels become refractory (close) and no more sodium enters the cell. The generation then enters the falling phase; potassium ions continue to leave the cell, the membrane potential begins to return to resting levels. Potassium channels then close and the sodium channels reset. Finally, in the last step of action potential generation, extra potassium ions outside the cell diffuse away. So, now that the action potential was generated, it needs to find a way to send its signal to the other neuron.
It does this through the process of conduction. The process involves sodium ions leaving the membrane as potassium ions enter. The process, repeated many times, creates action potential following action potential and so on. This process is adequate in transmitting the AP, but with longer axons or more important signals such as reacting to pain or extreme heat we don’t want to have to wait the couple of extra milliseconds for our body to react in this way.
This is where myelin and nodes of Ronvie enters the picture. Myelin, essentially fatty deposits, speeds up the process of conducting action potential by requiring far less repetition of the process. Action potential just zips through myelinated sections, only requiring regeneration in between the deposits, known as the nodes of Ronvie. The entire process s of conduction sends the action potential towards its ultimate goal of reaching the other neuron. The conduction of action potential is important, but it still needs to be converted to a chemical signal and reach the other neuron to perform its function. Chemical conversion begins in the originating neuron. In the neuron are precursors, which, under the influence of enzymes, are synthesized into neurotransmitter molecules. These molecules are stored in the vesicles of the cell to await transmission to the adjacent neuron.
The electrical signal (action potential) reaches the membrane and causes the vesicles to fuse with the presynaptic membrane and release their neurotransmitters into the synapse. This is the chemical signal that the adjacent neuron needs. Some released neurotransmitters float in the synapse and bind with auto receptors, preventing any further neurotransmitter release. Others float across the synapse and bind with the postsynaptic receptors, thereby completing the action potentials task of transmitting a signal from one neuron to another. Cell “C” on the handout is an Astrocyte, a macrogila. Its function is to provide nutrients to the neurons. It does this by wrapping one end around a blood vessel and extracts the nutrients from the blood inside. Its other end is wrapped around the synapse, almost connecting the two neurons, and it delivers these nutrients to the neurons.
👋 Hi! I’m your smart assistant Amy!
Don’t know where to start? Type your requirements and I’ll connect you to an academic expert within 3 minutes.get help with your assignment