Microorganisms and Diseases: 9th Grade Federal Board PDF

# Microorganisms and Diseases: Unit - 5 ## Objectives After completing this chapter you will be able to: - Know about the diseases and their causes. - Understand the spread of germs. - Explain how to protect against germs. - Know that smoking is injurious to health. - Understand ment...

# Microorganisms and Diseases: Unit - 5 ## Objectives After completing this chapter you will be able to: - Know about the diseases and their causes. - Understand the spread of germs. - Explain how to protect against germs. - Know that smoking is injurious to health. - Understand mental illness. - Understand the difference between drugs, medicines and narcotics. ## Human Diseases Human diseases are caused by different organisms. These are micro-organism, fungi, malarial parasite, ascarises and thread worms. Microorganisms are very minute organisms which can be seen only with the help of a microscope. ## Bacterial Diseases Several harmful human diseases are caused by bacteria. Some of the common bacterial diseases are mentioned below. ### Tuberculosis (T.B.) This disease is caused by bacterium called Mycobacterium. It is a wide spread and long lasting disease. The main symptoms of the disease are: - Chest Pain - Blood in sputum - Prolonged coughing #### Preventing T.B. This disease is common in those people who live under unhygienic conditions, take poor food and breathe polluted air. The disease spreads by coughing, sneezing and spitting of a TB patient. Un-boiled milk also carries T.B bacteria. In this disease, mostly the lungs are affected. In severe cases, the patient may spit blood along with sputum during coughing. The disease can be controlled by improving living conditions of the people, especially the patient, and by adopting and providing these following facilities: - Proper food, fresh air and proper rest can improve the recovery of the patient. - The victims of this disease should be kept in isolation or sanatoria to control further spreading of disease. - The disease is curable but prolonged and persistent treatment is necessary. - Infants must be immunized with BCG against T.B. ### Whooping Cough It is a disease of the infants. The symptoms of the disease are: - The infant coughs actually for a minute after which air rushes into the lungs, producing a whistling sound called "whoop." - Due to acute coughing, delicate linings of the lungs and capillaries are damaged. - The infant gradually gets weaker and reduced to a skeleton. #### Preventing Whooping Cough This disease can only be controlled by immunizing infants by the DPT injections. The injections are administered in a typical method. | Dose | Time | | ----------- | ----------- | | 1st dose | 6 weeks | | 2nd dose | 10 weeks | | 3rd dose | 14 weeks | | Booster dose | 18 months | DPT contains three vaccines: - D for Diphtheria - P for Pertussis (whooping cough) - T for Tetanus ### Diphtheria It is also a disease of the infants. The bacterium attacks the epithelial cells of the nose, throat and larynx and produces boils. These bacteria produce toxic substances which kill the neighboring cells. The trachea and larynx of the patient become non functional. The heart muscles get weak, which may lead to death. Infants should be immunized against this disease by vaccination. ### Tetanus It is a rare but dangerous disease. The disease-causing bacteria are found on animal dung, where they reproduce rapidly. They enter the human body through wounds or cuts. Once inside the body, they reproduce rapidly and produce a toxic substance that affects the nervous system of the patient. In the early stage in the infection, the patient feels headache and becomes lazy. Later on, the patient feels difficulty in opening his mouth, his neck becomes stiff and he has difficulty even urinating. There is no remedy for the disease, and the patient faces death. The disease can be avoided by administering the injections of ATS, i.e. Anti tetanus serum, at the time of getting any injury. Artificial immunity can be achieved by periodic use of vaccines. ### Typhoid It is a common disease. Nowadays, the use of antibiotics has helped to control the disease. A vaccine is also available which gives artificial immunity against typhoid. ### Cholera It is an infectious disease of the digestive tract. The bacterium is transmitted through contaminated food and water. House flies play an important role in the spread of these bacteria. The main symptoms are vomiting and diarrhoea. It causes dehydration and loss of salts from the body. Severe attacks may cause the death of the patient. The attack of the disease can be avoided by the vaccine. In case of attack, the use of ORS (oral rehydration salt) and antidiarrheal drugs is most important. ## Viral Diseases Several harmful diseases are caused by viruses; some of them are mentioned below. ### Small Pox It is a fatal disease but fortunately it has now been eliminated from the world including Pakistan. During this disease, small boils appear on the whole body of the patient and each boil is filled with pus cells. The patient must be isolated from the rest of the family members. The only remedy or control is the use of vaccine. The vaccine against small pox was the first to be discovered. ### Polio This is a disease of infants in which the lower limbs are damaged, making them disabled. Main symptoms are fever, headache and stiffness in the neck. Under severe attack, the legs are paralyzed. The polio virus spreads through air and water and the infants below the age of five are the victims. The only treatment is the use of polio vaccine at regular intervals up to the age of five years. Its vaccine is available in the form of oral drops. A campaign has been lodged by the government of Pakistan with the collaboration of UNICEF to vaccinate as many infants as possible against polio. ### Influenza It is a common disease of humans. It is not a dangerous disease. It is caused by the influenza virus. The virus spreads through the air and by the sneezing of the influenza patient. The symptoms are mild fever, redness of the eyes, irritation in the nasals and a runny nose. The disease automatically diminishes after 4-5 days. Complete rest and use of drugs reduce the intensity of the attack. ### Cough and Fever It is also a common disease of infants. The patient suffers from cough and fever but afterwards small boils appear on the body, i.e. face and chest. These boils are light gray in color with red circles around them. The disease gradually diminishes within 10 days. After the disease is over the patient becomes immune to this disease for the rest of his life. The infants are now immunized by the use of vaccines which has greatly reduced the rate of occurrence of this disease. ### AIDS This is a fatal viral disease which has threatened the mankind. AIDS stands for Acquired Immunity Deficiency Syndrome. It is caused by a virus called HIV (Human Immunodeficient Virus.) This virus kills/destroys the white blood cells of the patient with the result the immune system of the patient is destroyed. The patient becomes the victim of various other diseases such as TB, Pneumonia, Typhoid etc. because of the loss of natural resistance. This multiple attack proves fatal. #### Preventing the spread of AIDS The disease spreads mostly through blood transfusion, contaminated syringes and direct contact with the patient. A vaccine against this disease in the experimental stage. ### Hepatitis It is a disease of the liver caused by a virus. It is mainly of 3 types, i.e. Hepatitis A, Hepatitis B and Hepatitis C. The virus invades the liver cells and destroys them at a very fast rate. If the immune system of the patient becomes active, the disease can be controlled; otherwise it proves fatal. It is characterized by jaundice, abdominal pain, liver enlargement, fatigue, loss of appetite and sometimes fever. The disease is spread through blood, saliva and mothers milk. Hepatitis A can also spread through the contact of feces from the infected person. Vaccines are now available for Hepatitis A and B and not for C. ## Other Diseases There are several other important diseases which are not caused by bacteria or viruses, but some other organisms. Some of them are as under. | Disease | Causative organism | | ----------- | ----------- | | Cancer | Not clearly known | | Malaria | Plasmodium (a unicellular organism) | | Ring Worm | A fungus | | Ascariasis | Intestinal worm (Ascaris) | |Thread worm | Intestinal worm (Enterobios) | ### Cancer It is a strange disease that can trap persons of any age group. Cancer is the uncontrolled growth of cells which form a cyst or a tumor. These cancerous cells may stay at one place of the body or they may spread in the whole body through the blood and may cause tumors in other parts of the body. If the cancerous cells are restricted to one particular area of the body, they can be removed with the help of surgery and if these cells spread in the whole body, it becomes dangerous and causes the death of the patient. Cancer can occur in any part of the body but the lungs, mouth, skin, intestine and breasts are the common targets. #### Causes of Cancer Cancer can be caused by many factors that may be physical, chemical or biological. Any factor that can stimulate the unwanted growth in the cells can cause cancer, e.g - Sunrays may cause skin cancer. - Certain drugs may cause cancer. - Viruses have also been found to cause cancer. - Smoking can cause cancer of the mouth and lungs. - Certain chemicals have been found to cause cancer. - Tin packed food materials are also considered to causes cancer. #### Identifying Cancer Following symptoms can help to identify the disease. - A persistent open wound. - A cyst or tumor under the skin. - Constant headache with vomiting. - Prolonged indigestion with the loss of weight. - Persistent cough and swelling in the throat. It is important to confirm the diagnosis of cancer with the help of clinical tests which include blood test, biopsy analysis and sonography. #### Treatment for Cancer With the passage of time, the treatment of this disease is possible but quite difficult. It can be treated at its early stage, but later it becomes rather impossible. Much work is being done, all over the world, to cure the disease. At present there are three methods to control/cure the disease. - Chemotherapy: Several medicines have been devised and discovered to treat the cancer. - Surgery: A tumor can be removed, with the help of surgery, at its early stage. - Radio Therapy: Special radiations are used to kill the cancerous cells or tumors. ### Malaria It is a common disease of the third world, i.e. Asia and Africa where the living conditions are not up to the mark. The disease is caused by a unicellular microorganism called Plasmodium. It belongs to the animal kingdom and phylum Protozoa. It is transmitted through the mosquito called Anopheles. The female mosquito carries the germs in its saliva, and when it bites a person to suck the blood, some saliva is left at the wound. The plasmodia (plural of plasmodium) in the saliva enter the human body through the cut surface. Once in the blood stream, it enters the red blood cells and destroys them at a very fast rate. If the drug (quinine) is not administered, the patient becomes weak and pale in a few days. The disease can be controlled by following precautions: - Remove standing water ponds or ditches or fill them completely, removing the breeding places of mosquitoes. - Regular spraying of DDT in the houses and drains to kill the mosquitoes. - Taking anti-malarial drugs immediately in case of attack. Now a days very safe and effective drugs are available in the market. - Getting the houses screened. ### Ring Worm It is a skin disease caused by a fungus. The fungal hyphae penetrate into the skin, generally in the legs, and form ring-like structures on the skin. It causes itching and discomfort to the body. The disease can be avoided by: - Keeping your environments clean. - Don't move barefooted in the fields. - Have regular baths. #### Treatment for Ring Worm The disease is curable by the use of proper anti-fungal skin creams and ointments. ### Ascariasis Ascariasis is a universal disease of the human intestine found in dirty and unhygienic areas. It is more common in children under the age of 8 years. It is caused by a round worm called Ascaris lumbricoides and therefore the disease is called Ascariasis. The worm is long and cylindrical with pointed ends #### Causes of Ascariasis The infection is caused by the ingestion of small eggs along with the food, water or dirty and dusty hands. The children with this disease become weak and pale. They also undergo the shortage of vitamin A, which may be a problem for the eyes and affect the vision. #### Precautions to prevent Ascariasis These worms keep on moving in the body from one part to the other, and may cause Jaundice, Pneumonia and Appendicitis. Following precautions can save our children from this disease. - To wash the hands before every meal. - To use boiled water for drinking purpose. - Proper disposal of the faeces and sewage. - Overall cleanliness in the house and surrounding areas. In case of attack of the disease, the patient may be taken to the doctor. ### Thread Worm Thread worm causes disease, mostly in children #### Recognizing Thread Worm The thread worm lays eggs around the anus, the last part of the alimentary canal where the female thread worm is resting. This condition causes itching and the patient can not live without scratching the affected area. The eggs get attached to the fingers of the infected child and may cause re-infection in the child. The best indication is the scratching habit of a child in the anal part of the body. Following precautions may help to reduce the occurrence of disease. - To wash the hands before every meal. - Immediate treatment of the infected child. - The bed and clothes of the infected child be washed with antiseptic drugs. - Nails be trimmed properly. - Faeces and sewage be disposed of properly. ## Causes of Disease The germs or disease-producing microorganisms are spread in various ways. The main agencies involved in the spreading of germs are: - Air - Water - Food - Touch or direct contact - Faeces - Animals - Cuts and wounds - Blood transfusion Most of the germs are present in the form of spores in the air. They can enter the human body during breathing or through the mouth. Air is a very good medium for the dispersal of germs. The dust in the air contains a large number of spores of germs. T.B is mainly caused by the germs that travel through the air. Fresh and dust free air is essential for good health. ## Precautions to avoid Germs Water is also a good source for the spread of germs. Germs can easily live and grow in water. The germs of cholera and diarrhea may spread through the water. It is advisable that the drinking water may be boiled. In villages, where hand pumps and proper water supply is not available, water must be boiled for drinking purpose. Rotten fruits, vegetables and spoilt and contaminated food are a source of spreading of germs. Never keep your edibles uncovered. Such spoilt food is toxic or poisonous and cause great trouble in the alimentary canal. Several diseases spread due to direct contact with the patient, e.g. AIDS, TB and plague. The direct contact with such patients should be avoided. Many germs spread through the faeces of the patient. If the faeces are not properly disposed off, they after getting dry, spread in the air and transmitted to other healthy persons. The faeces should be burried properly in the soil. The pet animals and cattle are also the source of germs. Various germs get attached to the animal’s body and reach you. The pet animals be given regular bath with anti-septics. The cattle should also be washed regularly to avoid such contamination. Cuts or wounds should never be left open. They are the gates of germs. Every cut or wound should immediately be washed with some antiseptic material and covered properly with bandage. The germs of AIDS and Hepatitis are transferred through the blood. The blood must be checked for its germs from some recognized laboratory, before transfusion, when needed. ## General Precautions to Avoid Germs Microorganisms or germs are present all around us in the air, water and soil. We can save ourselves from these germs by observing following precautions. - Most of the germs are killed by boiling water. Our surgical instruments must be sterilized otherwise there is a chance of infection. We must use disposable syringes. Unboiled milk should not be used at all as it contains the germs of several diseases. The milk must be boiled before use. - Animals carry the germs of various diseases. Such animals must be washed regularly Animals carrying diseases must be killed and buried in the soil. Now a days the pet animals are also vaccinated for various diseases so that they become immune to various diseases. - The patients suffering from infectious diseases should be isolated from the rest of the family members. Their clothes and utensils should also be isolated. It will help to save the life and health of rest of the family members. - A very effective and simple way to have a healthy life is to keep yourself clean. Have bath regularly, wash your hands before every meal, clean your teeth regularly and above all keep your surrounding clean. Germs always grow on dirty places. - Water is one of the major source for the spreading of germs. If the drinking water is boiled, all of its germs are killed and it becomes suitable for drinking. - Proper disposal of sewage is essential to keep the area clean. If not properly disposed of, it mixes with our drinking water and food, which is very dangerous for our health. ## Drugs Proper use of vaccines, especially at the infant stage, make the bodies immune against many fatal diseases. ### Antibiotics It is a type of medicine that kills or stops the growth of the germs. Antibiotics have saved the man from various fatal diseases. The use of antibiotics should be under the medical advice. ### Smoking Smoking is injurious to health. It has now been realized all over the world that smoking causes several fatal diseases and must be discouraged at all levels. During smoking, we inhale toxic gases in our lungs which then diffuse into the blood and taken to all parts of the body. Smoking can cause following fatal diseases. The diseases of the throat, wind pipe and lungs are called respiratory diseases which are caused by smoke & smoking. It may cause cancer of the lungs. The rate of occurrence of heart attack and other cardiac disorders is much more in people with the habit of smoking. Cancer, blood pressure and skin diseases are also caused by smoke and smoking. ### Mental Illness It is a condition in which the behaviour of a person is considered abnormal as it deviates from the general norm of the society. Such persons are called mentally ill or abnormal. Mental illness is basically of two types. - Neuroses - Psychoses #### Neuroses It is a mild disorder in which the person is not functionless in the society. The patient never loses sense of responsibility in his environments. His behaviour is not injurious to himself or society. Simple psychotherapy can cure the patient and he does not need hospitalization. #### Psychoses It is a severe disorder in which the patient becomes functionless to some extent in the society. The patient looses his sense of responsibility. His behaviour may become injurious for himself or the society. Such patients must be hospitalized for the use of drugs or shocks. There are several factors for such mental disorders, only a few are mentioned here. - Biological factors: Such as secretions of certain hormones or neurotransmitters. - Inherited factors: They are due to a change in the gene or part of the chromosome. - Social factors: Economic stresses and social stresses. It also includes depersonalization. - Physiological factors: Prolonged illness, some medical disorder, Toxic and drugs can affect the brain. Brain injury may also cause mental illness. ## Drugs Every drug has its effects on the person’s mind, body, life and those around him. It is important for us to know what a drug is, what are its uses, how are they used and when the same drug becomes harmful to the person using it. A drug can be defined as “any substance which, when taken in the body, changes the functioning of the body. It is a substance that can lead to addiction, if a drug is used to get relief. It is the proper “use” of the drug, and when the same drug becomes part of our daily routine, and one becomes uncomfortable without using it, it becomes the “abuses” of the same drug. It can be understood by the following example. To relieve the severe pain, a doctor will give us an injection of Morphine. Morphine is manufactured from OPIUM. If these injections are used during normal days, just to get a state of extra comfort, a stage will come when we will be addicted to the drug and a state of discomfort will have to be faced without using it. This is what we call “addiction” or abuse of drug. Addiction is a condition in which a person desires or need to continue taking the drug and to obtain it by any means. It is actually a dependence on the drug. This condition is dangerous for the person, his family and the society. The most common drugs are Heroin, Bhang and Hashish. The injections of Morphine and Pethidine are also used by a particular segment of the society. Alcohol is also a common drug used by a large number of people. ### Heroin White or brown powder with a bitter taste. It is diluted by adding powder milk, sugar, sleeping pills and such other substances. It can be smoked or injected. #### Effects of Heroin The main effects on the body are: - Breathing and heart rate slows down. - Blood pressure becomes low. - Eye pupils become small. - The person goes to sleep. - Health gradually declines. - Ultimately one may die. ### Bhang / Charas These are the forms of hemp or Bhang plant (Cannabis sativa) commonly found as a wild plant on the waste lands. Charas includes the green leaves of the plant and Hashish (Marijuana) includes the flower tops of the plant. Hashish also comes from the plant juice. Different forms of this drug are used through smoke or in the form of a drink. #### Effects of Bhang / Charas The effects on the body are: - It reduces the body coordination. - It reduces the ability to make decisions. - One becomes dizzy, hungry and sleepy. - Eyes become red and the throat becomes dry. - Above all one becomes a useless member of the society, and loses interest in all social activities. - There is a risk of damage to the mouth, throat and lungs. - It may cause loss of fertility. ### Alcohol It is produced by fermentation of fruits, vegetables or grains. It is present in some tonics and cough syrups. The common effects are: - It causes drowsiness and dizziness, - It causes staggering and loss of balanced movements and concentrations. - A continuous consumption of alcohol may cause headache, nausea vomiting. - It may damage the liver or brain. - It leads to heart diseases and cancer. ### All Drugs The term is applied to all such compounds that produced insensibility to external stimuli as well as internal pains and unrests. They may be obtained from opium or Charas or Bhang. It is the official and moral duty of the state, as well as members of the society, to check this drug movement. The Government of Pakistan has established a comprehensive organization called ANF (Antinarcotics Force) which has its offices all over the country. ## Exercise 1. One meter is equal to ______ millimeters. 2. The tetanus causing bacteria are found on ________ 3. A virus can be seen under an _______ microscope. 4. Measles is a ______ disease. 5. Malaria is caused by a unicellular organism called _______ **True or False** 1. Most of the germs are killed in the boiling water. 2. Measles is common diseases of old people. 3. ATS is administered against cholera. 4. Polio virus can also cause disease to adults. 5. Smoking can cause the cancer of mouth and lungs. **Multiple Choice** 1. All the following diseases are caused by Bacteria except: - Whooping Cough - Tetanus - Diphtheria - Hepatitis 2. Ring worm is caused by: - Bacteria - Virus - Amoeba - Fungus 3. It is a type of medicine that can kill the germs: - Antigen - Antibody - Antibiotics - Anti coagulant 4. Which is the following is the disease of digestive tract - Cholera - Tetanus - Small pox - Diphtheria 5. All the following methods are used to cure cancer except: - Chemo therapy - Surgery - Radio Therapy - Hydro therapy