Our brain loves to eat with you. It weighs only about 2% of body weight, but at the same time requires as much as 20% of cardiac output for itself. All this blood is supposed to bring oxygen and glucose to the brain.
The problem is that our brain does not know how to store nutrients. He hovers somewhere out there in his fantasies and meditations, not caring at all about food. Therefore, the brain is completely dependent on the flow of blood.
Fortunately, the arteries in the brain are designed in such a way that they can reflexively regulate blood flow on autopilot. These vessels literally contain muscles that can make the lumen of an artery narrower or wider. The blood supply to the brain is directly related to the diameter of these arteries.
If high blood pressure presses on the brain, then the arteries inside the head narrow. So less blood flows to the brain and it will not swell. It is bad for him to swell. It is also locked inside the skull. Swelling causes the brain to strangle itself against the skull bone.
If blood pressure drops, then the arteries dilate, and a crowd of sluggish red blood cells unwillingly weaves through them, bogged down in pools of glucose and other nutrients. If the arteries were narrow, then this whole procession would be stuck halfway, and the brain would not receive any glucose or oxygen. Therefore, at low pressure, the arteries expand as much as possible and let everyone in, in the hope that someone will bring a treat to the brain.
Such regulation is effective in the range of mean arterial pressure from 60 to 150 millimeters of mercury. Remember a story about mean arterial pressure? It is necessary to subtract the lower from the upper pressure, divide by three and add the lower.
In this range, the arteries of the brain provide it with oxygen and nutrient requirements. But if you go out of range, then the brain will be damaged.
At low pressure, red blood cells no longer even weave, but barely crawl through the arteries. Part of the brain can starve to death.
If the pressure is too high, then the liquid part of the blood will flow through the wall of the arteries and saturate the brain. It will swell and wedge between the bones of the skull. Also a bad option.
And this, brothers, we have not yet been distracted by all sorts of blood clots flying into the brain from the heart, or atherosclerotic plaques in the wall of the arteries.
Briefly speaking
If your mean arterial pressure is in the range of 60 to 150 millimeters of mercury, then the blood supply to the brain will be maintained by itself. You have nothing to do there. Everything works on autopilot there.
And if the mean arterial pressure is out of this range, then you will already be racing in an ambulance, and nothing will depend on you either. Convenient, right?
Exceptions to the rule
There are, of course, exceptions. Firstly, this coveted range only on average fits into 60-150 millimeters of mercury. All people are different and they may have options.
Secondly, if you stubbornly ignore the increase in blood pressure, then the arteries of the brain will get used to such an outrage and shift the cherished range somewhere higher.
After this, the normal regulation of blood flow will no longer be achieved. It turns out that high blood pressure slowly flattens your brains, and when you try to lower it, you will leave the cherished range, and your brains will suffer from a lack of blood.
From what the conclusion: control the pressure from a young age. If later, in your old age, you want to lower it in order to live longer, then your vessels will not always be ready to meet you. They will simply refuse to regulate the blood supply to the brain and leave you to be devoured by a stroke.
Do you think the pressure of 190/100 will fit into the range where the arteries of the brain can still cope?
