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. What is inhalation/exhalation?

5. How many respiratory movements do the people do?

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.

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.

The intestines, in which food undergoes chemical and mechanical changes, occupy the central portions of the abdominal cavity. The small intestine is only 1.5 to 2 inches, the large intestine is up to 2.5 inches 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 being 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.

 

VI. Coronary Heart Diseases

1. Why are the coronary arteries called so?

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? What do people experience in this condition?

5. Why heart and artery diseases have been recently the number one health problem in the world?

The coronary blood vessels got their name, because they encircle the heart like a crown, or corona. These vessels transport almost 230 ml of blood every minute over the surface of the heart.

Any sudden blockage of the coronary artery deprives the heart of its blood supply. Cardiac cells die, heart contractions may cease, and circulation may come to a standstill. If a coronary artery is completely plugged, the condition is called a coronary occlusion or heart attack. An occlusion in main coronary arteries is very serious and may cause sudden death. Other causes of the coronary disease include heavy physical exercise, aging, dietary habits, obesity, smoking, or hypertension.

Pain which had been developed in the heart may be due to a bloodflow deficiency in the coronary vessels. It is felt in the left arm and shoulder. Such pain from the heart has been called angina pectoris. Angina pectoris may not actually be noticed, or it may be experienced only from time to time.

Fortunately, the great majority of coronary disease patients will recover and will be able to lead active lives, when they receive proper treatment and medical supervision. There are many preparations which have been effective and are under clinical investigation at the present time.

Heart and artery diseases are the number one health problem in the world. Coronary heart disease, illness of the blood vessels supplying the heart, is responsible for the greatest number of deaths (over 50 per cent of all cardiovascular diseases). Causes of other cardiovascular disease deaths, in order of decreasing importance, are stroke and hypertension.

 

 

VII. Respiratory Diseases

1. Why are respiratory diseases so dangerous?

2. Which respiratory diseases do you know?

3. What can cause asthma?

4. Why does bronchitis occur?

5. Which symptoms of pneumonia can you name?

The respiratory tract is subject to infection more frequently than any other part of the body. The upper respiratory tract, the nose, throat and trachea, are affected more often than the lower, the bronchi and lungs. The deeper the inflammation, the more serious are its consequences, some diseases may be even fatal.

Asthma is a common long term inflammatory disease of the airways of the lungs. Asthma can be caused by allergies, infections, or pollution. Asthma symptoms include coughing, wheezing, and chest tightness, which can be controlled with proper treatment.

Bronchitis is a respiratory disease in which the mucus membrane in the lungs' bronchial passages becomes inflamed.As the irritated membrane swells and grows thicker, it narrows the tiny airways in the lungs, resulting in coughing.Other symptoms may include shortness of breath and wheezing.The cause of bronchitis is often smoking tobacco. If the source of irritation is an infection the disease will be receiving the treatment of a physician.

Pneumonia is an inflammation of the lungs, which affects primarily the air sacs - alveoli. Its symptoms are coughing, fever, chest pain, shaking and hard breathing. It may occur after a cold or the flu, because these illnesses make it hard to fight infection. Risk factors include other diseases such as diabetes, heart failure, a history of smoking, a stroke, or a weak immune system.

 

VIII. Digestive Diseases

1. Which digestive disorder is the most common?

2. What is heartburn?

3. What is appendicitis?

4. Name the standard treatment for appendicitis.

5. What symptmoms of digestive diseases do you know?

There are many types of digestive disorders, and their symptoms vary depending on the problem.

Ulcer is the most common condition. It is an erosion in the lining of the digestive tract as a result of the action of the enzyme pepsin.  Ulcers damage the lining of the stomach because of bacterial infections or medications. Spicy foods and stress may aggravate ulcers, but do not cause them. Antibiotics or antacids usually alleviate problems long enough for minor ulcers to heal. Since the secretion of gastric juice is increased, proper diet should be neccessary for the suppression of secretion.

Heartburn or acid indigestion results in stomach acid backing up into the esophagus to create a burning sensation or sour taste in the mouth. Acid reflux occurs because the lower esophageal sphincter does not close properly. Some people may get heartburn from certain foods or smoking.

Appendicitis is an inflammation of the appendix, a pouch that projects from your colon on the right side of your abdomen. The appendix doesn't seem to have a specific purpose. Appendicitis causes pain in the lower right abdomen or around the navel. As inflammation worsens, appendicitis pain typically increases and eventually becomes severe. Standard treatment is surgical removal of the appendix.

In general, a patient should see a doctor if he or she has severe abdominal pain, weight loss, heartburn, nausea and vomiting.

 

IX. Kidney Diseases

1. Which parts of the kidney are susceptible to disease?

2. What is glomerulonephritis?

3. How do we call diseases involving the tubules?

4. What causes Bright’s disease?

5. 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 prescuption of conservative treatment such as forcing fluid, sedation, etc.

                                    

                                          X. Congenital Heart Defects

1. What are congenital heart defects?

2. How many newborns have congenital heart defects?

3. Why do congenital heart defects happen?

4.  Are there many treatments for the congenital heart defects?

5.  When does the human heart begin to form?

6.  What can increase the risk of congenital heart malformations during

  pregnancy?

7. An extra chromosome is associated with congenital heart disease, isn’t it?

Congenital Heart Defects

 

Congenital heart defects are abnormalities in the heart's structure that are present at birth. Approximately 8 out of every 1,000 newborns have congenital heart defects, which can range from mild to severe.

Congenital heart defects happen because of incomplete or abnormal development of the fetus' heart during the very early weeks of pregnancy. Some are known to be associated with genetic disorders, such as Down syndrome, but the cause of most congenital heart defects is unknown. While they can't be prevented, there are many treatments for the defects and any related health problems.

Congenital defects usually are treated with surgery, catheter procedures, and sometimes medication.

Cardiac surgery and cardiac catheterizations are now performed on younger children — in fact, it's common for them to be done during infancy or even the newborn period, which has many long-term advantages.

Although nothing can be guaranteed with 100% certainty, most kids with heart problems can enjoy happy and healthy futures.

The human heart begins to form as a single tubular structure at about the fourth week of pregnancy. By the eighth week, this tube will gradually increase in length, eventually twisting upon itself. A wall, or septum, grows to divide the upper (atrial) and lower (ventricular) chambers into left and right sides. Four valves made of tissue develop, which keep blood moving forward through the cardiac chambers, lungs, and body as the heart pumps.

Multiple genetic and environmental factors interact to alter the development of the heart during the early stages of a fetus' development (the first 8 to 9 weeks during pregnancy).

Uncontrolled diabetes, alcohol or drug abuse, or exposure to industrial chemicals during pregnancy also can increase the risk of congenital heart malformations. Some chromosome abnormalities, in which there is an extra or missing chromosome (or part of a chromosome) are associated with congenital heart disease.

                           

 

                                   XI. Infectious diseases

1. What are the symptoms of chickenpox?

2. What are the symptoms of measles?

3. What are the symptoms of rotavirus?

4. What infection diseases do you know?

5. What infection disease is also called rubeola?

6.  Is rotavirus or measles the leading cause of severe, dehydrating diarrhea      in infants?

7. Can children be protected from chickenpox?