Chapter 12 6

--------------- aging of arteries --------------- Factors such as high blood pressure, high blood sugar, and smoking may cause ruptures in the smooth inner walls of arteries.To repair this breach, the body uses cholesterol as a filler.However, if the cholesterol-carrying protein is a "bad" protein (low-density lipoprotein, LDL), it causes inflammation, which signals white blood cells to protect the site quickly, and the resulting platelets that form promote clot formation.This clot can suddenly block an entire artery, leading to heart attack, stroke, sexual dysfunction and memory loss. 1.Something causes the "inner layer" to rupture The inner layer spasms the outer layer Blocks the middle layer Inflammation and spasms make the artery narrower Inflamed plaque ruptures the inner layer 2.Cholesterol filled the holes, but in a messy way. 3.Platelet clots form on cholesterol 4.Blood clot blocked the artery

--------------- Cholesterol Stucco (1) --------------- The former is due to the invasion of toxic substances such as nicotine and homocysteine.When cells are damaged, they pull away from each other, creating ruptures.At this time, the formed rupture must be closed as soon as possible to protect the inner wall of the blood vessel.There are many factors that can trigger a rupture, most of which are within our control, such as high blood pressure, high levels of compounds such as homocysteine ​​in the human blood, smoking, chronic inflammation such as periodontitis of the gums or sexually transmitted diseases, stress , anger, and high blood sugar levels.Most of these factors are within our control.Even if the mother and all the uncles have these unfavorable health conditions, it does not matter that the blood pressure can be brought down to the standard value through physical exercise or dietary modification (we will discuss this further below), and if necessary, medication .Homocysteine ​​can be genetically influenced, or it can be caused by a diet that is too high in protein or too little in folic acid, a vitamin.Using condoms, we can avoid STDs.By flossing and brushing regularly, we can prevent gum problems.Likewise, by controlling each of the factors that trigger the opening of blood vessels (see "Healthy Youth Action Plan" below), we can prevent openings in blood vessels.Cholesterol fills the openings in blood vessels that appear in the body, which in turn causes inflammation and can lead to more serious blockages.Vascular blockage

When there is a problem (rupture or nick) in the inner wall of an artery, the body feels uncomfortable because the middle layer of the blood vessel is in contact with the blood.Thus, our bodies fill the inner wall wounds with "mortar" like a bricklayer repairing a wall. (The "mortar" itself only makes matters worse, as we'll get to in a moment.) Although there is a kind of stucco— Cholesterol is terrible here, but it wouldn't be fair to dismiss its role across the board.Cholesterol is actually very important to the fulfillment of bodily functions. "Bad" cholesterol (LDL) is the one to get slammed, but good or healthy cholesterol is transported through the body by high-density lipoprotein (HDL), which acts like a spatula to patch walls in the arterial system, So this cholesterol is to be commended.It has a simple and compact structure, but it is not small, searching around in the arteries to scrape off the excess "plaster".Bad or nasty cholesterol is transported by low-density lipoproteins (LDL), which are like bad balloons, bulky, fluffy, unstable, and easily rupture when they collide with the walls of arteries, forming cholesterol fragments.If you have high levels of LDL in your body (maybe it's from your diet, maybe it's genetics), as soon as the lining of your arteries is damaged, the body sends LDL "filler mortar" to the scene.The human body, eager to heal the wound, fills the affected area with "bad" cholesterol, and the "mortar" will be used too much, rising above the rupture in the blood vessel wall.And that's just the beginning, this will also stimulate the immune system, attracting white blood cells to try to protect, remove "bad" cholesterol, and calm the body from damage.White blood cells secrete toxic substances that normally fight infection, but now cause generalized inflammation.Inflammation and cholesterol form blister-like areas on the blood vessel wall, called foam cells, which will increase the injured area, increase the content of cholesterol filling, and even make the surface of the arterial wall rougher, causing further inflammation. leaving holes and depressions.It's like high school kids throwing a party at their house over the weekend while their parents aren't there, the kids make a mess of the place, new guests keep coming, and no neighbors call the police.These giant foam cells are so greedy that the human body's blood supply is gradually unable to keep up with their growth rate.At this time, some foam cells will starve to death due to ischemia, and the dying cells become "irritable", just like we sometimes get hit by static electricity when we comb our hair, electric charges are also generated on these cells.This charge attracts more "rogue boys" or sticky platelets.They like to travel in groups and form blood clots in the arteries.So, first the problem is a ruptured blood vessel, then too much "filler" (bad cholesterol) or too little removal of "scraper" (healthy cholesterol), then inflammation, and finally cholesterol-induced blood clotting.Clotting platelets are blood cells that look like crumpled sheets and do a lot for the body.For example, if you accidentally cut yourself with a razor, having platelets can stop the bleeding and keep you from bleeding to death.Usually, the platelets have a good demeanor, calm and steady, but once they encounter an emergency, such as the inner wall of the artery is filled with cholesterol, they will act immediately.When the platelets hit an uneven patch in the blood vessel wall, they break up into granules and cling to the wall like a lifesaver. (If the blood vessel is uneven because of a skin cut, you should be glad that the platelets arrived in time, because they can clot in the broken vessel and eventually become a scab, which helps restore hemostasis.) If the blood vessel is uneven because the platelets are firmly attached In potholes in the arterial wall, especially charged with dead cells, platelets form a blood clot on top of the stimulated, inflamed area, bringing more protein to the spot, causing the blood to coagulate further.This inflammation and potholes will drive the platelets to accumulate until one day - wow!The walls of the inflamed blood vessels grow thicker, attracting too many platelets, which form too many blood clots that completely block the artery.As a result, the heart tissue nourished by the vascular blood transfusion lost the source of nourishment for survival, hovering on the verge of starvation and death.Now, let's set aside the cholesterol "party" in the arteries for a moment and wonder if there is any other reason why blood clotting is the unwanted guest that the arteries don't want.Sometimes, blood clots that "get together" in the arteries will want to keep going down the road.The result of this situation is not just annoying, but potentially fatal.Once the blood clot travels down the artery, it may "group" in smaller places, completely blocking the passage and preventing blood flow.If such a "party" takes place in a vital part of the body, all "celebration" ends forever, and very quickly.The arterial problem mentioned above also shows one of the most peculiar phenomena of heart disease: because blood clotting has a bad habit of shifting the "party" place, sometimes patients with severe arterial blockage, for example, 90% of the arterial wall is blocked, On the contrary, his physical condition is better than that of patients with 50% blockage rate.The specific mechanism is discussed below.If for twenty years a "party" has been held all over one's arteries—

--------------- Cholesterol Stucco (2) --------------- That is, the platelets aggregate, and the blood channel continues to narrow—— Then there are at least a few years in between when the body is learning how to use other means to do the work of the arteries.This is called blood supply backup.It's like the bridge you have to go to work every day. It can only allow one-way traffic at a time, thus causing traffic jams.After you've cursed furiously for a while— Weeks or months - find a new way to the office.In order to solve the "traffic" problem of aortic blockage, the human body will produce new blood vessels——

This is an adaptation that humans have in order to resist injury --------------- hint --------------- A blockage of a leg artery is the same as a blockage of a heart artery.What about the result?Pain in the legs when walking (in the past this condition was almost always linked to smoking, but now we are discovering that there are other causes of leg pain - the same as heart disease, stroke or sexual dysfunction).Treat leg pain with the methods described in this chapter's "Action Plan for Healthy Youth," along with regular walking, because this type of exercise stimulates blood flow in the body to find new ways to nourish otherwise ischemic tissues.This "backup of blood supply" means that the body can rescue itself if we give it the chance.

If you fly a lot, you should get up and walk around every two hours, or sit in your seat to stretch your legs.This can prevent deep vein thrombosis (or blocked veins in the legs).Sitting in a fixed position for a long time can cause this health problem: without moving the legs, blood clots can form.The clot can also travel to the lungs, blocking blood flow to the lungs (which is bad).Moving around or moving your legs allows the veins in your legs to carry blood throughout your body, preventing clotting.Before a long-distance flight, you should also take 162 mg of aspirin (that is, two aspirin for children or half a regular aspirin, drink a glass of water) to dilute the platelet concentration and reduce the risk of deep vein thrombosis.

hint All arteries in the body dilate when exposed to a gas called nitric oxide, which stays in the body for a short time.Once the nitric oxide is broken down, the body rapidly makes new nitric oxide.But arteriosclerosis (see Figure 2.1 "Damage to the inner wall of the artery") slows down this process.Without enough nitric oxide in the body, the arteries cannot open and provide enough energy to the heart or legs when walking or exercising.Therefore, once the inner wall of the artery is damaged, even if there is no artery blockage, the human heart or legs will still have insufficient blood supply.sexual response.Once the blood vessel is completely blocked, the surrounding ischemic tissue will send a signal by releasing proteins, requesting the body to develop new blood supply pathways.The ischemic tissues of people who exercise regularly will also require more blood supply, so the requirements for blood supply backup methods will also increase accordingly.But if you rely too much on the bridge that keeps you late every day, there will be a day when you walk to the toll booth and the whole bridge is completely closed, blocking you there.At this point, there is no "miracle" to help you - it is impossible for you to go to work.In the same way, let's look at the situation where blood clots "settle down" in already narrowed arteries.If the vascular blockage is only 50%, the blood may flow freely, and the body will think that there is no need to build additional highways and alternative bridges; but once the clotted volume expands and fills the pathways, the main bridge of blood flow is closed, and the heart suffers. Less than enough oxygenated blood, and the party is over.The result is the same process described above for the expansion of inflammation: the heart tissue that the associated blood vessels are responsible for nourishing is deprived of vital nutrients.Without backup access, the blood clot completely shuts off the artery, and the heart muscle that is "irrigated" by the arterial blood begins to die.

--------------- the electrical system in your body --------------- Please think about it, what keeps our hearts beating?Yes, the heart needs a constant supply of blood (which is why smooth arterial walls are so important), but it also needs the all-important pulse that keeps it beating steadily an average of 3.3 billion times in a lifetime."Party" in the arteries -- Blockage of blood vessels can also affect the normal rhythm of the heartbeat.In fact, about half of all patients with coronary heart disease also end up with a problem with the body's electrical circuitry that affects the heart rhythm (U.S. Vice President Dick Cheney, for example).The problem with the human body's electrical system is a lack of stability, which can also be called confusion.After part of the heart muscle dies due to arterial blockage and ischemia, the muscle cells near the dead cells lose their stability, become disorganized, and no longer perform their functions normally.They start fighting each other instead of supporting each other.The muscle cells are too busy fighting to deliver the electrical impulses that make the heart beat (see Figure 2.2).The clash between cells can turn into a frantic heart "flurry" known as atrial fibrillation.A strong heart muscle is no longer graceful and rhythmic like a ballet

The sinoatrial and atrioventricular nodes in the heart conduct electricity when they make rapid contact, controlling the rhythm of the heart's beating.This electrical system can be "shorted" by abnormalities in the cells of the rest of the atria and the cardiovascular system, with the result being abnormal heart rhythms, such as fibrillation.Superior vena cava, sinus node, left atrium, right atrium, atrioventricular node, pulmonary vein, tricuspid valve, inferior vena cava, more like a dance floor at four in the morning— Everyone just squirms for themselves.This situation is fatal, because the force of the chaotic twisting of muscles is not enough to send blood to all parts of the body.To get the heart beating back to its original normal rhythm requires a powerful electrical shock (the shock pads you see on TV provide that shock).One of the miracles of modern medicine is that people prone to heart rhythm problems can have an "implantable automatic cardioverter defibrillator" (AICD) implanted directly in the chest.The device detects an arrhythmia and automatically defibrillates the heart, restoring the heartbeat to normal.The heart, like your home, also has a "foyer" - the atrium, which stores the blood flowing into the heart.When fibrillation occurs in this relatively unimportant room, people experience heart palpitations.Unlike heart patients who need AICD implants, such patients sometimes need other treatments, such as pacemaker implants, radiofrequency ablation surgery, or medication, which involves taking drugs that lower blood levels and prevent the constantly moving atria. A stroke is caused by a buildup of blood clots in the wall.