IV. The Structure and Function of the Digestive System.
I. The Skeleton.
1. Which part of the skeleton is the most important?
2. What classes do the naturalists divide all the animals into?
3. What do the bones of the body include?
4. Where is the skull? What do the bones of the head include?
5. What do the bones of the trunk include?
6. Which organs do the ribs protect?
7. How does the wrist work?
8. How many bones are there in the framework of the wrist and hand?
The bones form the skeleton of the body. The most important part of the skeleton is the backbone. It is so important that naturalists divided animals into two classes - those which have a backbone and those which have none. All the higher animals have a backbone, or vertebral column and they are called vertebrate animals. The others are called invertebrate animals.
The bones which form the body include the bones of the head, the bones of the trunk, the bones of the lower and upper limbs.
At the upper end of the backbone there is the skull. Inside the skull there is the brain. The bones of the head include the bones which make up the box-like structure, the skull, and freely movable bone which forms our lower jaw.
The bones of the trunk include the spinal column, the ribs and the breastbone. The ribs form a strong cage - the chest, inside of which there is the heart and the lungs.
The arms join the body at the shoulder, and the shoulder consists of two bones – the collar-bone and the shoulder-blade. In the wrist there are eight small bones. They are bound together, but their large number allows the wrist to bend freely. Next come the bones of the hand itself. There are five long bones in the palm. Each of the fingers has three bones, and the thumb has two. Thus we have twenty-seven bones in the framework of the hand and wrist alone.
II. The Cardiovascular System. Blood.
1. What is the cardiovascular system? What does it include?
2. What is the center of the circulatory system?
3. How many chambers does the heart have?
4. What do the left and the right heart do?
5. Name two valves in the heart.
6. Which types of vessels do you know?
7. What is the blood?
8. Which types of blood cells do you know?
The cardiovascular system is the system of blood circulation. The cardiovascular system includes the heart, the arteries, the veins and the capillaries of the human body.
The center of the circulatory system is the heart, which lies behind the breastbone and between the lungs. The heart is a hollow muscle which has four chambers: two ventricles and two auricles, or atrium. The heart is a pump, but we may think of it as of two pumps - the «right heart» and the «left heart». The right heart receives blood from the veins and pumps it into the lungs. It has a one-way valve, the tricuspid valve, which separates its chambers. From the left heart the well-oxygenated blood moves into the aorta. The left heart has the mitral valve.
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Arteries are blood vessels that receive blood from the ventricle and lead it towards other organs. The aorta is the largest artery in the body. The arteries divide and form smaller vessels with thinner walls. The smallest arteries are the arterioles, which divide into capillaries. The capillaries begin to join into larger vessels. Such larger blood vessels that carry blood to the heart from the organs are the veins.
The blood is a red fluid, which clots when escapes from a blood vessel. It mainly consists of plasma, leucocytes, lymphocytes and erythrocytes. Erythrocytes (or red blood cells) provide oxygen to tissues, lymphocytes form our immune system, and leucocytes (or white blood cells) defend the organism from infection.
III. The Respiratory System. Respiration.
1. Why is respiration so important?
2. What gases are involved in breathing?
3. What parts of the respiratory system does the air pass on its way to the alveoli?
4. Describe the mechanism of breathing.
5. What is inhalation/exhalation?
6. How many respiratory movements do the people do?
7. When does increased respiration occur?
Respiration is the process of breathing, which occurs in all living things, both plants and animals. It is important, because it sustains life, and interruption of breathing causes death. Breathing includes two main gases: oxygen which is delivered to body cells and carbon dioxide which is removed from the organism. Nitrogen, which makes up about 79 per cent of the atmosphere, is not involved in the breathing process.
Air is breathed through the mouth or nose into the oral cavity, or pharynx. It then passes through the voice box, or larynx, into the windpipe, or trachea. The trachea divides into two smaller tubes, bronchi, one is going to each lung. The bronchi divide into bronchioles, which lead directly to alveoli. The exchange of life-giving gases is effected through the walls of the alveoli.
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Respiration consists of rhythmically repeated inhalations and exhalations. An inhalation involves a contraction of muscles, an expansion of the lungs, and entrance of atmospheric air into the lungs through the air passages. Inhalation is followed by exhalation. The muscles relax, the lungs become compressed, the pressure in them rises and the air rushes out through the air passages.
An adult makes 16-20 respiratory movements per minute, children make more movements. Physical exercise is usually accompanied by faster respiration. Increases respiration is also observed in many diseases.
IV. The Structure and Function of the Digestive System.
1. Where is the largest cavity of the body situated?
2. What organs does the abdominal cavity contain?
3. Why is the liver so important?
4. What does the gall-bladder serve for?
5. What are the characteristics of the stomach?
6. How do we distinguish «small» and «large» intestines?
7. What is digestion?
8. What types of digestion do you know?
The abdomen is the largest cavity of the body. It is surrounded by the thorax, two pelvic bones, lower ribs and the abdominal muscles, and it is also supported by the spinal column. The organs of the abdominal cavity are the liver, the gall-bladder, the stomach, the intestines, the pancreas, the spleen, the kidneys and the bladder.
The liver is a large organ that weighs about 1.5 kg and lies under the right ribs. The liver is important, because it secretes bile which participates in the digestive process and has a defensive function, i.e. some toxic substances are detoxified in the liver.
The gall-bladder lies beneath the right lobe of the liver and serves as a bile reservoir.
The stomach lies under the left ribs. It serves as a container of food, which is partly digested in it. The size and shape of the stomach vary with amount of consumed food, and its capacity is some 1-2 litres.
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The intestines, in which food undergoes chemical and mechanical changes, occupy the central portions of the abdominal cavity. The small intestine is about 4 cm to 5cm, the large intestine is up to about 6 cm wide.
Digestion is the breakdown of food into smaller components that can be absorbed into the bloodstream. The process of digestion is due to the activity of many enzymes, chemicals, and physical processes within the digestive tract. Digestive processes may be classified as salivary digestion, when occurring in the mouth; gastric digestion in the stomach; and intestinal digestion in the small intestine. With normal digestion, between 95 and 100 per cent of all carbohydrates, fats, and animal proteins are absorbed.
V. The Urinary System.
1. What is the urinary system?
2. What are the parts of the urinary system?
3. Where are the kidneys placed?
4. What are the functions of the parenchyma of the kidney?
5. What does the bladder serve for?
6. Where is urine formed?
7. What does urine consist of?
Various harmful and unnecessary substances are continually being formed in the human body. The urinary system is the system which excretes the largest part of the waste products of the body. The urinary system consists of the kidneys, ureters, urinary bladder and urethra.
The kidneys are placed one on each side in the lumbar region of the spine, on the posterior abdominal wall. A kidney is a bean-shaped organ, which weighs about 150 grams and is covered by membranes. The kidneys contain one million small tubes, which have to excrete products of metabolism and control the concentrations of most body fluids. These small and various tubules make up the parenchyma of the kidney.
The bladder is a reservoir for urine, which is situated in the cavity of the pelvis. The capacity of the bladder of an adult is about 350-500 ml.
The urine is formed in the kidneys from many waste and harmful substances contained in the blood. Then it passes through the ureters into the urinary bladder. The bladder is emptied through the urethra, which leads to the exterior of the body. The wastes are excreted as urine, which is normally composed of approximately 96 per cent water, plus urea and various salts. The healthy adult seems to excrete an average of about 1.5 litres of urine from the body daily. Through this system blood is being continuously depleted of water and the loss must be made up by the ingestion of new water.
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VI. Our University
1. When was the BSMU founded?
2. How many faculties are there in your university?
3. What does the curriculum include in the first year?
4. What is the practical course at the end of first and second years?
5. What facilities do students have for study?
6. How many terms is the academic year is divided into?
7. Where can graduates continue their education?
8. What faculty do you study at?
Our University
Bashkir State Medical University was founded in 1932. It trains doctors of different specialties.
There are 5 faculties in our university – the faculty of general medicine, the faculty of dentistry, the faculty of pharmacy, the faculty of pediatrics, the faculty of preventive medicine.
The first-year curriculum includes such pre-clinical subjects as Anatomy, Biology, Chemistry, Physics, Histology, Latin, English and others. Anatomy is the most important subject of the first year.
During the first two years the students get acquainted with the structure of the human body, the functions of different organs and all the processes which take place in the body.
From the third year medical students begin to study clinical subjects such as general surgery, pharmacology, internal diseases, eye diseases, traumatology, orthopedics and psychiatry.
The students have all facilities for their life and study. There are four hostels, a lot of laboratories, a library, reading-rooms, canteen in our university.
Every day students attend practical classes and lectures. They perform different laboratory works. There are two terms in the first year. Each term lasts for about 16-19 weeks.
The academic year is divided into two terms.
After each term the students take examinations and have several credit tests.
At the end of the first and second years, students have a practical course, where they perform the duties of nurses. After their fourth and fifth years they work as doctor’s assistant at the department of internal diseases, obstetrics, surgical department.
At the end of the sixth year, students take a final state examination and get their diploma, which certifies them as doctors.
After receiving a diploma, students can take three-five year residency course.
VII. Coronary heart diseases
1. What coronary heart diseases do you know?
2. What does the sudden blockage of the coronary artery result in?
3. What are the conditions caused by coronary occlusion?
4. What is angina pectoris?
5. What do people experience in this condition and how is it treated?
6. What does Hypertension mean?
7. What are the causes of hypertension?
Coronary heart diseases are the number one health problem in the world. The coronary blood vessels transport almost half pint of blood every minute over the surface of the heart. Any sudden blockage of one of the coronary arteries deprives that section of the heart of its blood supply. An occlusion in main coronary arteries is very serious and may cause sudden death.
Pain in the heart may be due to a blood-flow deficiency in the coronary vessels. It is referred to the left arm and shoulder. Such pain from the heart is called angina pectoris. Cardiovascular diseases may be caused with high blood pressure. Most physiologists consider the blood pressure reading 150/190 as excessive and it is called hypertension. Hypertension is very common. There are some causes of hypertension: kidney disease; excessive narrowing of arteries, diet, obesity and others.
Fortunately, the great majority of coronary diseases patients recover if they receive proper treatment.
VIII. Respiratory infections
1. Why are respiratory infections so dangerous?
2. What parts of the respiratory tract are infected more often?
3. What does chronic bronchitis mean?
4. What is the most important symptom of the chronic bronchitis?
5. What is the main treatment of the chronic bronchitis?
6. What does the term “catarrh” indicate?
Infections of the respiratory tract
The respiratory tract is a subject to infection more frequently than any other part of the body. Respiratory infections stand third as a cause of deaths. The deeper the inflammation, the more serious are its consequences: pneumonia is frequently fatal. Inflammation of the deeper respiratory structures results from a downward extension of a relatively harmless inflammation in the upper structures: nose, throat and trachea. Inflammation of the mucous membrane is of the so-called catarrhal type: the term “catarrh” indicates a chronic state of inflammation. Excessive production of mucus by ciliated mucous membrane causes the condition known as chronic bronchitis. Frequent coughing is the most important symptom of chronic bronchitis. The main treatment of chronic bronchitis consists of eliminating the irritation that causes it.
IX. Diseases of the abdomen
1. What does jaundice mean?
2. How many types of jaundice are there?
3. What procedure has to be performed to diagnose a liver diseases?
4. Why is ulcer a common condition?
5. What causes ulcers?
6. What does the patient usually complain in the case of ulcers?
7. What is the treatment of ulcers?
Diseases of the abdomen
There are a lot of types of disorders and ailments of the digestive tract. I name several of them. Jaundice is the most obvious symptom of liver disease. Jaundice is divided into three main types: obstructive jaundice, hepatocellular jaundice, hemolytic jaundice. The fact that sera from different cases of jaundice can give different types of reaction is used for differentiating between different types of jaundice.
Ulcer is a common condition. A peptic ulcer is an erosion in the lining of the digestive tract as a result of the action of the enzyme pepsin. Most of the symptoms are ascribed to the high degree of acidity of the juice. The second factor is emotional stress. Peptic ulcer disease can be called a psychosomatic disease. There are two types of ulcers: gastric and duodenal.
They are very similar effects. The patient usually complains of a pain after meals (within the first hour in case of gastric ulcer, from three to four hours after meal in duodenal ulcer). The patient should have a proper diet and a prompt treatment.
X. Kidney diseases
1. Which parts of the kidney are susceptible to disease?
2. What is glomerulonephritis?
3. Why is a clearance test used?
4. How do we call diseases involving the tubules?
5. What causes Bright’s disease?
6.What is athero-sclerosis of the kidney?
7. Why are stones in the kidneys so dangerous?
There are three parts of the kidney which are susceptible to disease: the glomeruli, the tubules and the blood vessels.
The disease in which the glomeruli are particularly involved is called glomerulonephritis. In glomerulo-nephritis, the glomeruli become clogged so that the blood no longer flows through them. Here a clearance test is useful; it will show that smaller quantities of filtrate are formed than normally.
Diseases involving the tubules are called nephroses. They are usually caused by poisons of various kinds, such as mercury, bismuth, uranium, or carbolic acid. Some degree of tubular degeneration occurs, in such diseases as diabetes, malaria, pernicious anaemia, and traumatic shock. Finally, athero-sclerosis of the kidney may occur, reducing the total blood flow through the kidney's blood vessels.
A common disease of the kidney, known as Bright's disease, includes a number of different conditions. The discovery of albumin in the urine usually indicates a faulty working of the kidneys. It means that albumin from the blood plasma pass through the renal tubules, and excrete in the urine. At the same time the damaged tubules fail to eliminate fluid, which causes swelling in legs and face.
Stones in kidneys can be carried for years producing no symptoms. If the stone is large, or several are present, the infection may progress to a pyelonephrosis, resulting in the destruction and loss of the kidney. Most stones in the ureter will pass into the bladder by the prescription of conservative treatment such as forcing fluid, sedation, etc.
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