There is a topic that I particularly liked a lot when I studied it and understood it, because it is something that is very common in all human beings when something is not going well in our body, it is a warning that tells us "be careful, pay attention ", and this is pain..
To understand this topic it is important to keep in mind the functioning of our nervous system (roughly), additionally the structure of the cells, at least of the parts involved in the process of pain generation. But don't worry, below I will share with you some very easy to understand information and I know you will like to stay with the knowledge that you will acquire.
Let's understand the mechanism of pain production and additionally how the most commonly used analgesic drugs work to reduce the sensation of pain.
In the following image you can see in a schematic way- muscle cells (it can be any other type of cell) and near them sensitive nerve fibers, which are in charge of perceiving any type of injury and transmitting the information to the brain so that this central organ processes it and emits a reaction.
It is important to note that in the cells there is an enzyme (macromolecule) called Cyclooxygenase that is in charge of producing a substance called "prostaglandin ", this substance is produced when there is some type of injury and it is the one that activates the sensory fibers of pain so that they communicate to the brain.
Then the process would be the following: when an injury occurs at the level of any part of the body (blow, burn, wound, etc) the cells that are located there will activate the enzyme cyclooxygenase that will produce the prostaglandin inside the cells, later this substance will be released to the extracellular space, which is where the sensory neurons are located, which will be activated and will send the signal to the brain saying that there is a damage in process, so that it sends the signal that will make us withdraw the hand, the foot, or whatever is being damaged from what is producing the damage.
This is a process that takes place in a matter of milliseconds, the speed is very high, that is why at the slightest sensation we tend to react.
I have to say a few things in a general way:
There are different types of sensory nerve fibers for pain, some are fast pathways, that is to say that the transmission of pain is immediate. But there are also slow fibers, that is why sometimes we hit something, and the pain intensifies later, a few seconds later.
There are pain fibers throughout the body, but they are not activated for the same reason. For example: at the level of the intestine, these fibers are activated only when this hollow organ is distended. That is the reason why when we have a lot of gas, that the intestine is distended is that we feel pain, not before.
At the level of the skin, the nerve endings that perceive pain are basically in the middle layer. When a very deep burn occurs, the sensation of pain is usually lost, Why?, what happens is that the nerve endings are burned and there is no one to transmit the information to the brain, that is why people with very extensive and very deep burns lose the ability to feel pain.
An interesting fact, the brain does not hurt, when we feel a headache it generally comes from the muscles located in the head, obviously on the outside, or by distension of the blood vessels, but not from the brain itself, since the brain processes the information, but it does not have the pain receptor cells, did you know that?, you already know.
I hope it is very clear the process and these generalities that I have explained so far. I must also say that at a biochemical level the reality is that it is a very complex process, in which other cellular systems are involved in order to execute the fact of "transmitting pain ", but I have tried to simplify the process to make it much easier to visualize.
The other thing I offered in the introduction to this publication was to explain the process by which drugs help us to relieve pain. I can safely say that among the most commonly used analgesics are ibuprofen, diclofenac and acetaminophen.
With the first ones something happens, a very important adverse effect, and that is that they usually cause gastritis and even ulcers when the consumption is very constant.
I mentioned that the Cyclooxygenase is in charge of producing prostaglandin, the detail is that there is cyclooxygenase-1 and .2, they are similar but have different functions. The one involved in the painful process is the cyclooxygenase-1, but the -2 has an important role in the production of one of the key components in the protection of the gastric mucosa.
When we take a medication such as ibuprofen or diclofenac, what they do is that they BLOCK the cyclooxygenase and prevent it from producing prostaglandin, which prevents the pain from manifesting itself and also, if the pain is already present, it decreases as the production of prostaglandin stops. As simple and complex as that.
And this same medication paralyzes the function of cyclooxygenase-2 (which produces the substance that protects the gastric mucosa), and that is when our stomach is unprotected and exposed to the appearance of gastritis and ulcers. But nowadays we have drugs that can be specific to block the function of cyclooxygenase -1 and not -2, such as Meloxicam, which relieves pain but does not affect the stomach.
I hope you have enjoyed this publication, I have created it looking for simplicity.
With all the intention that it will be of much benefit to those who like to read it. Any comments or suggestions are welcome.