The Circulatory system

The function of the circulatory system is to deliver energy, nutrients, Oxygen to all systems of the human body and to remove Carbon dioxide and waste products of metabolism of the body.

17. The 3 main components of the circulatory system are blood, heart and heart vessels. The blood consists of corpuscles divided into red blood cells (erythrocytes), white blood cells (leucocytes) and platelets and plasma. Red blood cells contain hemoglobin which is an Oxygen carrier. The white corpuscles combat foreign infectious agents. There are 4 types of blood : O, A, B, AB.

18. The heart is the hollow muscular organ divided into 4 chambers (right and left atrium, right and left ventricles). They are divided by the septum which prevents the blood from mixing. The right part contains the deoxygenated blood, the left one contains the oxygen-rich blood.

The heart is enclosed in a fibrous sack which is called pericardium. There are 3 layers of the heart: the muscular layer (the myocardium) which is located between 2 sheets of fibrous and elastic tissues,the epicardium (the outer layer) and the endocardium (the inner layer).

There are 4 valves in the heart. The mitral ((bicuspid) valve separates the left atrium and the left ventricle, the tricuspid valve separates the right atrium and the right ventricle, the pulmonary valve is located between the right ventricle and the pulmonary trunk, and the aortic valve can be found between the left ventricle and the aorta.

19. The blood vessels coming out of the heart are ascending and descending aorta, right and left pulmonary arteries. The blood vessels entering (=draining into) the heart are superior and inferior vena cava and right and left pulmonary veins.

Aorta is divided into arteries, the arteries branch into arterioles which are divided into capillary network. Superior and inferior vena cava branch into veins that are divided into ramifications of venules.

There are 2 types of blood circulation. The greater which is also known as systemic and the lesser (pulmonary).

20. The cardiac cycle consists of the 2 main phases :

• The systole during which the muscular layer of the heart contracts and due to it the ejection of the blood from the chambers of the heart takes place.

The diastole is the relaxation of the myocardium. During this phase atria and ventricles are filling with blood at the same time and all the valves are open.

21. The most common cardiovascular diseases are:

• Hypertension is a chronic medical condition in which the systemic arterial blood pressure is elevated (increased)
• Hypotension is an abnormally low blood pressure
• Ischemia(the death of the tissue) is a restriction of blood supply due to the thrombus, fatty deposits, spasm in the blood vessels resulting in damage of the vessels and dysfunction of the cardiac tissue.
• Angina pectoris (стенокардия) is severe chest pain due to ischemia(a lack of blood and oxygen supply) of the heart muscle due to obstruction (or spasm) of the coronary arteries.
• Thrombosis is the formation of a blood clot (a thrombus) inside a blood vessel obstructing the flow of the blood through the circulatory system.
• Atherosclerosis is a condition in which an artery wall thickens and hardens as the result of built up(=accumulation) of fatty deposits such as cholesterol blocks.
• Stroke or brain attack develops when a blood clot blocks an artery or a blood vessel breaks interrupting (=restricting) the blood flow to subarea of the brain.
• Myocardial infarction is commonly known as a heart attack. It’ s the death of the heart muscle from the sudden blockage of the coronary artery by a blood clot.

22. Myocardial infarction is commonly known as a heart attack. It’ s the death of the heart muscle from the sudden blockage of the coronary artery by a blood clot. The causes of MI include atherosclerosis, thrombosis, and hypertension. The race groups of the population include those who suffering from diabetes, alcoholism smokers the people under constance stress or the ones that are emotionally unset, or physically exhausted. Besides, MI can occur as the side effect of the drugs. The age is the factor that puts people at risk of developing MI. Furthermore, males are at risk more than females.

23. The cardinal sign of the MI is severe chest pain. I radiates to the left shoulder and arm, sometimes to the right arm, neck and the lower jaw, epigastrium and the upper back. The patient describes this pain as a sensation of tightness, pressure and squeezing. The other manifestations include the shortness of breath (dyspnea), headache and toothache, often hiccups, rapid pulse (palpitation), sweating, nausea, vomiting, heartburn and indigestion, general malaise, weakness, loss of consciousness and sudden death can occur in MI.

Though, many heart attacks are silent (symptomless) when the patient doesn’t even realize that.

24-25. There are 2 types of hypertension: the primary (essential) or secondary. The primary H accounts for 90-95 per cents of cases. This term means that the medical cause for high blood pressure isn’t found( remains unexplained). But there are some risk factors including cigarettes smoking, stress, obesity, excessive use of stimulants such as coffee and tea, drug abuse, high Sodium intake(=consumption). The secondary H accounts for 5-10 per cent of cases and is caused by the medical conditions that affect the kidneys, vessels, heart and endocrine system.

High blood pressure usually causes no symptoms, that is why this disease is called a silent killer. But when the complications develop, the warning signs associated with hypertension may appear. They often include headache, sweating, rapid pulse, shortness of breath, dizziness, nausea and vomiting , chest pain and visual disturbances (blurred vission).

26. The differences in clinical picture include the following:

• When angina pectoris attack occurs, it lasts from 3 to 5 minutes.
• In MI it lasts from 30 to60 minutes.
• In MI the pressure suddenly falls at first and then gradually rises.
• In AP the blood pressure increases.
• The AP attack is relived with rest, fresh air, nitroglycerin, which must be put under the tongue and dissolved.
• The MI attack requires the doctor’s immediate attention.

27. The measures ones should take to prevent the development of cardio-vascular diseases are:

1. To keep to a balanced diet( to avoid fast food, salty, fatty, sweet food, to eat more vegetables and fruits)

2. Not to overeat.

3. To avoid alcoholic beverages, cigarettes.

4. To say “NO!” to harmful drugs.

5. To have regular medical checkups, to monitor one’s blood pressure.

6. Not to take prescribed medicines.

7. To get enough sleep, rest and exercises.

8. To avoid extreme emotional reactions, overheating, over exhausting.

28. The AP attack is relived with rest, fresh air, nitroglycerin, which must be put under the tongue and dissolved.

29. The MI is a medical emergency that is why the patient requires the doctor’s immediate attention.

There are the primary measures that must be taken by the doctor to save one’s life:

The patient requires:

· Oxygen

· Beta-blockers (to improve the symptoms of ischemia)

· Antiplatelet drugs(aspirin)

· Morphine as a pain killer(when nitroglycerin isn’t effective)

· ACE inhibitors (they decrease mortality and the development of heart failure )

· Statins (prevent the formation of fatty deposits)

30. Anaemia is a deficiency in the number and quality of red blood cells. There are 2 types:

• Quantitative which means the changes of the number of erythrocytes;
• Qualitative which means changes of crescent shape of red corpuscles.

31. The main symptoms are: pale skin, fatigue, headache, shortness of breath, loss of appetite, loss of consciousness, fainting, irritation, loss of memory, muscular weakness, coldness and numbness of the extremities, intestinal changed stool color, palpitation, chest pain, spleen enlargement, burning sensation in the tongue, brittle hair and nails and strange food cravings.

• The mild cases of anaemia are treated with vitamin C, B12, folic acid, iron supplements, changes in the lifestyle and diet.
• The severe cases of anaemia are treated with oxygen regular blood transfusions, antibiotics, painkillers, steroids, removal of the spleen and chemical therapy.

32. Haemoblastosis is proliferation of the haemopoietic tissue, a disease of the whole blood system. It is characterized by the prevalence of proliferation of certain cells over their differentiation and the loss of their typical morphological and functional properties, substitution of these pathological cells for normal cells of the haemopoietic organs and the development of pathological haemopoiesis in various organs. The factors that can provoke the growth of haemoblastosis are cancerigenic substances and radiation.

33. there are 2 main theories that can explain the aetiology of haemoblastosis and tumors. There are the virus and genetic theory. Due to the genetic theory h. develops because of the congenital or acquired damage to the chromosome structures of low differentiated cells of the haemopoietic organs.

Moreover a clone theory has been launched recently according to which h. appears due to primary chromosome mutation in one of the haemopoietic cells.

34. The alimentary system consists of 2 main components: the gastro-intestinal tract and the accessory organs. The alimentary canal begins with the oral cavity or the mouth which contains 32 teeth, a tongue with taste buds, two gums, soft and hard palate. Then there are a throat or pharynx, esophagus or gullet, a stomach with gastric glands, small intestine that consists of duodenum, jejunum and ileum, large intestine which can be divided into cecum with vermiform appendix(extension), colon (ascending, descending, transverse and sigmoid) and rectum. The terminal part of the gastro-intestinal tract is anus.

The accessory organs of the alimentary system are liver with the gall bladder and the pancreas.

35. The process of digestion starts in the oral cavity, where the food is chewed, masticated and crushed with the help of the teeth, mixed by the tongue and moisture with the saliva produced by the salivary glands. In the mouth the bolus is formed and swallowed with the help of the tongue and throat. Then it passes down through the esophagus to the stomach through the cardiac sphincter. In the stomach the bolus is broken down and disinfected under the influence of the gastric juice(hydrochloric acid) produced by the gastric glands and churned(взбивается) with the help of wavelike movements of the stomach which is called peristalses. The contents of the stomach is propelled into the duodenum through the pyloric sphincter. In the duodenum digestion continues with the pancreatic juice produced by the pancreas and the bile produced by the liver. N the small intestine nutrients and water re absorbed through the intestinal walls. The mass is propelled into the large intestine, where the wastes are formed and stored in the rectum. The end product of the digestion or feces is excreted through the anus. In the large intestine water is absorbed by the body.

36. The principal functions of the alimentary tract are:

• Ingestion (swallowing) of the food;
• Digestion and conversion (transformation ) from complex substances into the simpler ones;
• Their transport to the point of their absorption into the blood stream;
• removal(excretion) of waste products.

37. Gastritis is an inflammation of the gastric mucosa. There are 2 types of gastritis: acute and chronic. Acute gastritis has a sudden onset due to the infectious causes: viruses, bacteria and protozoa or due to the toxicity and irritation(hyper secretion of hydrochloric acid).

The chronic gastritis is accompanied by disturbances in secretory and motor functions of the stomach. It develops when the causes of the acute gastritis are not detected in time.

The main causes of the acute and chronic gastritis are:

• Malnutrition(fried foods, fatty foods, refined foods, poor and combining, spicy, hot food, drinking with meals, constant overeating);
• Tobacco and alcohol;
• Stress;
• Prolonged medication;
• Chronic infections;
• Severe vomiting;
• Endocrine diseases;
• Metabolic disorders;
• Food allergies;
• Mechanical causes(injuries) during surgery, radio- and chemotherapy;
• Swallowing of a foreign object.

The symptoms are:

• Nausea and vomiting;
• Abdominal pain (crumbs)
• Diarrhea;
• Constipation;
• Fever;
• Headache;
• Muscle aches(myalgia);
• Dark blood in stool(malena);
• Blood in vomit (vomiting material looks like coffee grounds- haematemesis);
• Anorexia(loss of appetite, weight).

The treatment of gastritis depends on the underline cause. But the general treatment includes:

· Normalization of nutrition and lifestyle;

· Normalization of the work of central nervous system;

· Repairmen (restoration) of gastric mucosa with the help of diet therapy and antacids which neutralize hydrochloric acid;

· Normalization of gastric juice secretion with the help of proton-pump inhibitors. They decrease the production of hydrochloric acid by gastric glands;

If adequate treatment isn’t provided, gastric ulcer may develop which may transform into cancer.

38. Ulcerative colitis is an inflammation of the colon characterized by the appearance of ulcers of the colon. The causes of it are still unknown, but the scientists consider that genetic and environmental factors, autoimmune diseases, infections contribute to the development of u. c.

The most common symptoms are:

• Abdominal main;
• Depression;
• Rapid weight loss;
• Aches and pains in the joints;
• Fatigue;
• Changes in bowel habits(diarrhea, too frequent stool)
• Swelling of the bowel tissue;
• It’s redness, bleeding ulcers on the colon;
• Fever;
• Bright red streaks of blood in the stool (haematokisia);
• Bloating;
• Indigestion;
• Heartburn;
• A high erythrocyte sedimentation rate (ESR) the typical sign;

The treatment of u.c. depends on the stage of the disease. They are: mild, moderate, severe, fulminant.

In general the treatment of u.c. includes the use of antibiotics, immunosuppressions, steroids, anti-inflammatory drugs, painkillers.

In severe and fulminant cases the surgery is required. The doctor’s objective is remission rather than cure, because u.c. is a chronic condition.

The complications of u.c. include:

- Anaemia due to blood loss;

- Dehydration due to diarrhea;

- Appearance of ulcers on the tongue, lips, palate, pharynx;

- Inflammation of the iris;

- Arthritis;

- Gangrene of the skin;

- Deep venous thrombosis;

- Pulmonary embolism;

- Deformity of the fingers (“finger clubbing”);

- Cholangitis (inflammation of the bile ducts);

- Perforation of the colon, peritonitis;

- Cancer.

39. Appendicitis is an acute inflammation of the vermiform appendix located in the lower right abdominal area of the body. The appendix produces digestive enzymes, and also the mucus that neutralize toxins. This mucus usually travels into the large intestine. When the appendix is obstructed, the amount of mucus can’t decrease causing the bacteria which normally live in the appendix to multiply. The appendix swells and becomes infected.

The causes of the obstruction:

- Feces parasites;

- Enlarged lymph tissue of the appendix due to the infection in the gastro-intestinal tract or elsewhere in the body;

- Ulcerative colitis;

- Trauma of the abdomen and kicking of appendix;

The symptoms and signs include:

- Acute abdominal pain;

- The abdomen is sharply tense(острый живот);

- Nausea and vomiting;

- Loss of appetite;

- Constipation or diarrhea;

- Bloating;

- Leukocytosis;

- High Erythrocyte Sedimentation Rate;

- Low-grade fever.

The treatment may be surgical and non-surgical. Nowadays understanding the significance of the appendix as the organ with immunological functions the surgeons do their best to treat its inflammation with antibiotics, much liquid and soft diet. The surgical treatment is indicated when there is a risk of rupture of the appendix.

40. Peritonitis is an inflammation of the peritoneum. The peritoneum is a thin, transparent and glistening membrane covering the abdominal walls. During peritonitis it becomes infected, dull and opaque. P. can be divided into two types: primary and secondary.

The primary is caused by the infection from lymph nodes (1 % of all cases)

The secondary is caused by the infection from the gastro-intestinal and biliary tract.(95%)

The symptoms and signs are:

- Acute abdominal pain ;

- Swelling of the abdomen;

- Fever and chills;

- Loss of appetite;

- Thirst ;

- Nausea and vomiting;

- Limited urine production;

- Hypocratic face.

The treatment includes surgery which is directed at removing the source of the infection.

Antibiotics are injected into the peritoneal cavity.

The main complication is sepsis, when the infection penetrates into the blood stream and is spread to all organs, causing their dysfunction.

Date: 2015-01-29; view: 945