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Приготовление дезинфицирующих растворов различной концентрации
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DISORDERS OF THE HEART AND BLOOD VESSELS
Because of the constant activity of the heart and blood vessels, there is a wide range of potential problems and disorders. The two most common disorders are coronary artery disease, the principal cause of heart attack, and hypertension. Yet there are other kinds of problems that can affect the health of the valves, the heart muscle, the rhythm of the heart, or the ability of your blood vessels to circulate the blood to your tissues. Some problems, called congenital, are present at birth; others occur as the result of infection, hereditary factors, problems with the action of thyroid hormone on your heart, lung diseases that affect your heart, or trauma.
In the following pages, we will consider individually several dozen heart and blood vessel disorders, as well as some of the remarkable advances made in recent years in diagnosis and treatment for heart and circulatory problems. But before considering the problems, it is important to understand something about the basic interaction between the lives we lead and our health.
What we eat, our exercise patterns, whether we smoke, and a number of other lifestyle considerations have an impact on the health of our hearts as well as on other organ systems. So we will begin with the risk factors for coronary artery disease and what we can do to use that knowledge for longer, healthier lives.
Your primary care physician may treat some heart and circulatory disorders. However, your physician may refer you to a cardiologist, a specialist who has had additional training in the diagnosis and management of heart and blood vessel disorders.
Healthy arteries are like healthy muscles. They are strong, flexible, and elastic. Atherosclerosis is the condition in which fatty deposits accumulate in and under the lining of the artery walls. The name comes from the Greek word ather, meaning "porridge", because the fatty deposits are soft and resemble porridge. Blood cells (platelets) often clump at microscopic sites of injury to the inner wall of the artery. At these sites, fat deposits also collect. Initially, the deposits are only streaks of fat-containing cells but, as they enlarge, they invade some of the deeper layers of the arterial walls, causing scarring and calcium deposits. Large accumulations called atheromas or plaques are the principal characteristic of atherosclerosis. The greatest danger from these deposits is the narrowing of the channel through which the blood flows. When this occurs, the tissues that the artery supplies will not receive their full quota of blood. Pieces of the fatty deposits may be dislodged, travel with the blood flow, and finally obstruct an artery at some distant point.
Atherosclerosis may be discovered in the course of a routine physical examination. During examination of patient's neck, abdomen, or other parts of the body, the physician may hear a blowing sound if a narrowing of the lining of the arteries at one or more these points causes turbulence of the blood flow. The physician also will estimate the amount of blood flow by feeling for pulsations in the arteries at the wrists, legs, and feet. A decrease in pulsations is a reason to suspect partially obstructed blood flow.
More elaborate tests of circulation using sound waves often help in establishing the presence and degree of decreased blood flow. Ultrasound scan of the abdomen often is used to identify a suspected aneurysm of the aorta in the abdomen. Another test for locating the sites of plaques that narrow blood vessels is arteriography. In many cases, the diagnosis is not suspected until the artery is completely obstructed and the person has experienced a stroke, heart attack, or arterial thrombosis.
To some extent, the body can protect itself from narrowing of a particular artery by developing, with time, additional arterial connections that detour blood around the narrowed point. This is called collateral circulation.
Although atherosclerosis occurs to some extent in all middle-aged and elderly people and even may occur in certain young people, some people appear more at risk because of high blood cholesterol levels.
The best prevention and treatment of atherosclerosis is certain regimen, sound sleep, rest, and proper diet. Vitamins are widely used in the treatment of this disease. Other drugs administered in treating atherosclerosis are so-called lipotropic substances, which prevent fat from accumulating in the organism.
Leukemia is cancer of the body’s blood-forming tissues, including the bone marrow and lymph system. This cancer causes the formation of large amount of abnormal white blood cells. These abnormal white blood cells reach high concentrations in the bone marrow, lymph system, and bloodstream, and their accumulation can interfere with functions of the vital organs. Eventually, they overwhelm the production of healthy blood cells, including white and red blood cells and platelets. In addition to the overabundance of abnormal white blood cells, there is an insufficient number of healthy ones. Therefore, the body’s ability to fight infections is decreased. The deficiency in red blood cells means that the body’s organs do not receive enough oxygen, the shortage of platelets makes the blood clotting process less effective, leaving the body more vulnerable to bleeding and bruising. Because of all these effects, leukemia is fatal without successful treatment.
The causes of leukemia are not known. Researchers have proposed that certain chemicals and viruses might play a role. Susceptibility to leukemia may be inherited. The ailment runs in some families, and people with certain congenital disorders, including Down syndrome, are at higher risk of developing it.
The most common signs and symptoms of leukemia are fatigue, bone pain, fever, weight loss, swollen lymph nodes, bleeding, bruising, paleness, and headaches. In many cases they are absent. These cases are detected when routine blood tests give abnormal results.
Treatment of leukemia generally is simple chemotherapy. High-dose chemotherapy, along with bone marrow transplantation, sometimes is used. Therapy with antibiotics can help to prevent or can treat the bacterial infections that are frequent complications. Corticosteroid drugs also may be used with chemotherapy. The radiation therapy to the central nervous system also may be recommended. It has been designed to kill the cancer cells that may linger in the patient’s central nervous system beyond the reach of medications given orally or intravenously.
The digestive system is a group of organs that work like wrecking equipment to break down the chemical components of food, through the use of digestive juices, into tiny nutrients, which can be absorbed to generate energy for the body. This system also builds and replaces cells and tissues, which are constantly dying. Digestion begins in the mouth with the teeth, which grind the food into small particles; the tongue, a powerful muscle which detects "good" and "bad" flavors in food and manipulates the food between the teeth for chewing, and saliva, a watery fluid which lubricates chewing and swallowing and begins the process of digestion. The digestive system begins in the mouth, continues in the pharynx (throat) and esophagus and into the "gut" region: the stomach, small and large intestines, the rectum and the anus. Food is chewed, pulped and mixed with saliva to become a soft mass, which will easily travel down the esophagus. The tongue traps the food and forces it into the throat, which is a mass of muscles and tissues, which transports food into the gut system for final processing and distribution. The throat closes the top of the breathing pipes, but if the food accidentally enters these pipes, it goes down the "wrong way" and must be coughed up before the body chokes or asphyxiates. As food passes through the body, it is mixed with an unbelievable amount of chemicals, which break it down into small units that can be absorbed into the blood and lymph systems. Some is used for energy, some as building blocks for tissues and cells, and some is stored for future or emergency use. The liver and the pancreas also secrete digestive juices that break down food as it passes through the digestive ducts. Not all that we eat can be digested, so the waste must be disposed of in an efficient way. It may not be a savory ending for the food or drink we thought was so delicious in the mouth, but it is just as important for our health.
Peptic ulcers are holes or breaks in the inner lining of the esophagus, stomach, or duodenum. It has been determined that peptic ulcer generally occurs in the lower part of the stomach (gastric ulcer), in the initial portion of the duodenum (duodenal ulcer), and occasionally in the lower esophagus (esophageal).
The signs and symptoms of the peptic ulcer are the following: burning, aching, or hunger discomfort in the upper abdomen or lower chest (that is relieved by milk or food); black stools; bloated feeling after meals; and nausea or vomiting. In emergency cases the person has clammy skin and fainting.
The cause of ulcers is not fully known. Normally, the linings of the esophagus, stomach, and duodenum are kept intact by a balance between the acid and stomach juices and the resistance of these linings to injury. When the balance breaks down, the result may be a peptic ulcer. Recent research has shown that many ulcers may be secondary to bacteria called Helicobacter pylori (H pylori).
Peptic ulcers are not uncommon in our society. It has been estimated that the age at diagnosis peaks between 30 and 50 for duodenal ulcers and between 60 and 70 for gastric ulcers. Frequently, ulcers recur within 1 year after healing, sometimes without symptoms.
Some people may have an inherited disposition to ulcers. Peptic ulcers are 3 times more likely to occur in families of patients with duodenal ulcer than in the general population. And relatives of people with gastric ulcers have the very same kind of ulcer.
The goals of treatment are to relieve symptoms, heal the ulcer, prevent relapse, and avoid complications.
The vast majority of persons with peptic ulcer disease responds well to medication. The key to treatment is either decreasing the amount of acid present or strengthening the protective lining of the stomach or duodenum. The mainstay of treatment is a class of drugs that decrease the amount of acid produced in the stomach. These drugs are called H12 blockers. The usual course of therapy lasts approximately 6 weeks. Many people with ulcers harbor H pylori bacteria, which can be effectively treated with antibiotics. Twelve months after treatment, most people show no ulcer recurrence, while recurrence is more common after using standard ulcer medications.
However, if the person has an ulcer that does not respond to medical treatment or the person has serious complications such as hemorrhage, obstruction, or perforation, he/she may be a candidate for surgery.
“Gastritis” is a general term that means inflammation of the lining of the stomach. It can result from a number of causes, each of which may produce somewhat different symptoms, such as: upper abdominal discomfort, nausea and vomiting, and diarrhea.
Gastritis can occur as a result of acid-induced damage to the lining of the stomach when no ulcer is present. Excessive smoking or alcohol consumption are known to produce mild gastritis or to aggravate existing gastritis symptoms. Gastritis also can be a side effect of a number of prescription drugs. Severe stress due to burns, trauma, surgery, or shock may produce gastritis. Gastritis is also seen in some persons whose stomachs do not produce acid. In these cases, the lining of the stomach is atrophied. This condition may be associated with vitamin B12 deficiency and occurs in many older people. Even very healthy people may experience gastritis with some regularity.
In most cases, the symptoms of gastritis are relatively mild and short-lived, pose no real danger, and have no lasting effect. Occasionally, gastritis may cause bleeding, but it is rarely severe.
Antacids in liquid or tablet form are a suitable and common treatment of mild gastritis. If a person is troubled by excessive acid and antacids fail to provide relief, the physician may prescribe drugs such as cimetidine, ranitidine, or nizatidine, which decrease the amount of acid produced by the stomach. Medication to protect the lining of the stomach may be used.
V. Speak on the following topics:
2. Skeletal System.
3. Muscular System.
4. Digestive System.
8. Cardiovascular system.
SUFFIXES AND TERM-ELEMENTS
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