Diseased Organism example essay topic

Physical MedicinePHYSICAL MEDICINEPHYSICAL MEDICINE also called PHYSIATRY, PHYSICAL THERAPY, OR REHABILITATION MEDICINE, medical specialty concerned with the treatment of chronic disabilities and with the restoration of normal functioning to the disabled through physical modes of treatment, such as exercise. This specialized medical service is generally aimed at rehabilitating persons disabled by pain or ailments affecting the motor functions of the body. Physical medicine is one means employed to assist these patients to return to a comfortable and productive life, often despite the persistence of a medical problem. For centuries man used such natural physical agents as hot springs and sunlight to treat his ailments, but the development of physical medicine as a specialized medical service took place largely after World War I. Two factors influenced its growth in the 20th century -- epidemic poliomyelitis and the two world wars -- both of which created large numbers of young, seriously handicapped persons. Physical medicine was definitively established through the American physician Howard A. Rusk's efforts to rehabilitate wounded soldiers during and after World War II. Physical medicine then became available for the treatment of patients with such diverse problems as fractures, burns, tuberculosis, painful backs, strokes, nerve and spinal cord injuries, diabetes, birth defects, arthritis, and vision and speech impairments.

Physical medicine is closely associated with orthopaedic surgery, but it is also prescribed by physicians and surgeons in all branches of medicine. Physicians who specialize in physical medicine are called physiatrists. The objectives of physical medicine are relief of pain, improvement or maintenance of functions such as strength and mobility, training in the most effective method of performing essential activities, and testing of function in various areas. Tests cover such fields as muscle strength, degree of joint mobility, breathing capacity, and muscular coordination. The therapeutic means most commonly employed include heat, massage, exercise, electrical currents, and functional training. Since the 1970's these basic means have been supplemented and enhanced by psychological counselling, occupational therapy, and a variety of other treatments which may be used in concert to help the disabled person achieve the fullest possible life despite the persistence of his medical problem.

Heat is used generally to stimulate circulation and to relieve pain in the area treated. It may be applied by infrared lamps, shortwave radiation, or high-frequency electrical currents (diathermy); by hot, moist compresses or immersion in hot water (hydrotherapy); or by ultrasound. Massage primarily aids circulation and relieves local pain or muscle spasm. Exercise, the most varied and widely used of all physical treatments, is usually designed to do one or more of three things: increase the amount of motion in a joint, increase the strength in a muscle, or train a muscle to contract and relax in useful coordination with other muscles. In addition to its obvious use following stiffness or paralysis, exercise may be used to improve the breathing of patients with lung disorders, assist circulation, relax tense muscles, and correct faulty posture. In the late 20th century high technology was increasingly harnessed in efforts to rehabilitate paraplegics, quadriplegics, and others with severely impaired motor functions.

Microcomputers were developed that could send precisely coordinated jolts of electricity directly into the muscles of such patients, mimicking the cerebral impulses that could no longer reach their muscle destinations because of a severed spinal cord. The microcomputers's ophisticated programs enable them to contract a patient's muscles in unison so that he can actually stand and sit, walk, and even use his hands to perform relatively fine movements. Such devices were still in the experimental stage and were costly to make and use, but they seemed to be the most promising development yet in efforts to restore the power of movement to nerve injury victims. Other, less ambitious devices to help paralyzed patients include wheelchairs with specially equipped control systems that can be operated by the mouth and teeth movements of a quadriplegic. Mobile robotic arms have been developed that are equipped with a video camera so that they can move safely and intelligently about a patient's house.

These personal robots can receive and execute oral commands from the patient to perform such simple household tasks as filling a glass with water or taking a book off a shelf. Functional training teaches the impaired individual how to carry out most safely and effectively the activities of daily life. This training may mean learning to use crutches, a brace, or an artificial arm; or it may involve working out and practicing the movements required to do housework with the use of only one hand or the way to board public transportation with a stiff leg. Such training often requires long hours of practice; it may be facilitated by use of devices that make it easier to fasten buttons, hold a fork, or dial a telephone. Physical medicine and rehabilitation underwent a rapid expansion during the late 20th century, largely because of the development of antibiotics and other fundamental advances in modern medicine, which not only save the lives of many who would not have survived illness or injury in earlier decades but also prolong life in general. Physical medicine and rehabilitation are carried out by a 'rehabilitation team,' headed by a physiatrist who coordinates the team's efforts and assesses the areas of functioning in which the patient can improve.

The physical therapist uses exercise to improve the patient's muscle strength and functioning, and a rehabilitation engineer may provide a special mechanical aid or device to assist that functioning. Meanwhile a rehabilitation nurse keeps track of the patient's physical condition and provides him with basic medical care, while a psychological counsellor helps the patient cope with the discouragement or depression produced by the condition of physical disability. Respiratory or speech therapists may also be brought in to assist the patient with breathing or speaking difficulties. Eventually an occupational therapist and a social worker will help the patient adjust to life outside of the rehabilitation institute.

See also occupational therapy. Alternative or complementary medicine Persons dissatisfied with the methods of modern medicine or with its results sometimes seek help from those professing expertise in other, less conventional, and sometimes controversial, forms of health care. Such practitioners are not medically qualified unless they are combining such treatments with a regular (allopathic) practice, which includes osteopathy. In many countries the use of some forms, such as chiropractic, requires licensing and a degree from an approved college.

The treatments afforded in these various practices are not always subjected to objective assessment, yet they provide services that are alternative, and sometimes complementary, to conventional practice. This group includes practitioners of homeopathy, naturopathy, acupuncture, hypnotism, and various meditative and quasi-religious forms. Numerous persons also seek out some form of faith healing to cure their ills, sometimes as a means of last resort. Religions commonly include some advents of miraculous curing within their scriptures. The belief in such curative powers has been in part responsible for the increasing popularity of the television, or 'electronic,' preacher in the United States, a phenomenon that involves millions of viewers. Millions of others annually visit religious shrines, such as the one at Lourdes in France, with the hope of being miraculously healed.

Use of self-care and work and play activities to promote and maintain health, prevent disability, increase independent function, and enhance development. This form of therapy evolved from the recognition that work helps to restore the mentally and physically ill, particularly after the acute phase of illness has passed. Because any form of therapy must be dependent on others, any treatment program designed by an occupational therapist is coordinated with the work of doctors, nurses, and other related professional personnel in setting up a specific program for a patient. History. Patients have long been employed in the utility services of mental hospitals. In the late 19th and early 20th centuries, experiments were made in the use of craft activities to occupy mental patients.

This practice gave rise to the first occupational therapy workshops and later to schools for the training of occupational therapists. Later developments included problem-solving techniques, crafts, and work procedures for young people and industrial programs and activity programs of jobs for patients within the hospital. In 1952 a World Federation of Occupational Therapists was formed, and in 1954 the first international congress of occupational therapists was held at Edinburgh. a harmful deviation from the normal structural or functional state of an organism. A diseased organism commonly exhibits signs or symptoms indicative of its abnormal state.

Thus, the normal condition of an organism must be understood in order to recognize the hallmarks of disease. Nevertheless, a sharp demarcation between disease and health is not always apparent. The study of disease is called pathology. It involves the determination of the cause (aetiology) of the disease, the understanding of the mechanisms of its development (pathogenesis), the structural changes associated with the disease process (morphological changes), and the functional consequences of these changes. Correctly identifying the cause of a disease is necessary to identifying the proper course of treatment. Humans, animals, and plants are all susceptible to diseases of some sort.

However, that which disrupts the normal functioning of one type of organism may have no effect on the other types. An impairment of the normal state of an organism that interrupts or modifies its vital functions. A brief discussion of disease follows. The subject is treated in a variety of articles.

For a general discussion of human, animal, and plant diseases, see Disease. For a discussion of diseases categorized according to their cause or transmission, see Infectious Diseases; Nutrition: Diet and diseases; Occupational Diseases and Disorders. For a discussion of diseases associated with particular stages of human development, see Childhood Diseases and Disorders; Growth and Development, Biological. For a discussion of malignancy, which may affect any organ or tissue in the body, see Cancer.

For a discussion of disease-causing organisms such as viruses, bacteria, and parasites, see Bacteria; Viruses. For a discussion of bodily defences against disease, see Immunity. For a discussion of the diagnosis and treatment of disease, see Diagnosis and Therapeutics; Drugs and Drug Action; Medicine. For a discussion of diseases affecting particular organs, tissues, or processes, see Blood: Blood diseases; Circulation and Circulatory Systems: Cardiovascular system diseases and disorders; Digestion and Digestive Systems: Disorders and diseases of the digestive system; Endocrine Systems: The human endocrine system; Excretion and Excretory Systems: Excretory system diseases and disorders; Integumentary Systems: Skin diseases; Metabolism: Metabolic diseases; Muscles and Muscle Systems: Diseases and disorders of muscle; Nerves and Nervous Systems: Nervous system diseases and disorders; Reproduction and Repr Systems: Diseases of the human reproductive system; Respiration and Respiratory Systems: Diseases and disorders of respiration; Sensory Reception: Eye diseases and visual disorders and Ear diseases and hearing disorders; Supportive and Connective Tissues: Diseases of the supportive and connective tissues. For a discussion of neuroses and psychoses, see Mental Disorders and Their Treatment.

For a discussion of alcoholism and other drug addictions, see Alcohol and Drug Consumption. Disease most commonly is caused by the invasion of an organism by one or more outside agents. Typically the infectious organisms are microorganisms (e. g., bacteria, viruses, and fungi), but they also can include larger organisms such as parasitic worms or nonliving but harmful substances such as toxins or ionizing radiation. Disease also may result from changes within the organism -- an anatomical fault (congenital or acquired) or a physiological malfunction (e. g., diabetes, in which the body fails to secrete or adequately utilize insulin, a hormone that regulates blood-sugar levels). Other diseases are a combination of external and internal factors. An organism's failure to adapt to changes in its environment can produce damaging changes within it.

Physiological malfunctions and disturbances of normal growth can be induced by changes of diet or by invasion of microorganisms or other agents. Nearly all organisms are able to defend themselves against most diseases. Humans and other vertebrates have developed two strategies of resistance, called immunity, to invading agents: nonspecific immunity, which is present in all vertebrates at birth; and specific immunity, which is acquired only after stimulation by the presence of a certain microbe or its products (e. g., the virus that causes chicken pox). Immunity also can be stimulated artificially in humans or other animals by inoculating them with microorganisms that have been killed (as in typhoid vaccine) or weakened (attenuated) ones (as in measles vaccine), which produce the defensive immune reaction without causing the disease. Sometimes an organism's defensive reaction to invasion by an outside agent can become part of the disease. The crippling of the lungs produced by tuberculosis is caused partly by the destruction of lung tissue by the invading microorganisms (in humans, usually Mycobacterium tuberculosis) and partly by the fibrous tissue that the body lays around the infection in a defensive reaction.

Disorders of the immune response itself can produce autoimmune disease (e. g., rheumatoid arthritis) in which the immune response is triggered not by an outside invader but by the body's own tissues, which some cells fight against and try to reject. The immune system also can be disabled by an invading microorganisms, as is the case with the disease AIDS. Not all organisms that invade another produce disease. Some can establish a mutually beneficial relationship with their host without impairing its vital systems; for example, the bacteria that live in the gastrointestinal tracts of humans and other vertebrates make possible the digestive processes of their hosts. In addition, organisms that are pathogenic to one species may be harmless to another. A disease that becomes established in an organism usually requires some form of treatment.

In most cases, treatment consists of administering drugs that kill the causative agent, restore any physiological or biochemical imbalances that have occurred, or control the symptoms caused by the agent so that the affected organism can continue to function. Other forms of treatment include moving the diseased organism to another environment or removing the diseased parts from the organism. The most effective way to control disease is by preemptor y prevention. The best method is to eliminate a disease-causing organism from the environment, such as by killing pathogens or parasites contaminating a water supply.

Also effective is the disruption of a pathogen's transmission from one organism to another, either by avoiding contact with body tissues or fluids that harbour a pathogen or by eliminating an intermediary vector (e. g., killing the mosquitoes that transmit malaria to humans). Disease also may be prevented by removing a susceptible organism from an unhealthful environment, strengthening the organism's defences by making it healthier, or vaccination. From disease Treatment Treatment of disease in the affected individual is twofold in nature, being directed (1) toward restoration of a normal physiological state and (2) toward removal of the causative agent. The diseased organism itself plays an active part in both respects, having the capacity for tissue proliferation to replace damaged tissue and to surround and wall off the noxious agent, as well as defence and detoxification mechanisms that remove the causative agent and its products or render them harmless. Therapy of disease supplements and reinforces these natural defence mechanisms. Metabolic faults also may sometimes be corrected -- for example, by the use of insulin in the treatment and control of diabetes -- but more often specific therapeutic measures for idiopathic diseases are lacking.

However, advances in gene therapy may be able to correct defective genes that result in disease. When disease is produced by environmental factors, there is commonly no specific treatment; only removal of the affected individual from exposure to the agent generally allows normal detoxification responses to take over. Again, there are notable exceptions, as in the treatment of lead poisoning with acid, an agent that forms complexes with lead that are excreted by the kidney. Treatment of infectious diseases is more effective in general; it assumes several different forms.

Treatment of diphtheria with antitoxin, for example, neutralizes the toxin formed by the microorganisms, and host defence mechanisms then rid the body of the causative microorganisms. In other diseases, treatment is symptomatic in the sense of restoring normal body function. An outstanding example of this is in cholera, in which disease symptoms result from a massive loss of fluid and salts and from a metabolic acidosis; the highly effective treatment consists of restoring water and salts, the latter including bicarbonates or lactates to combat acidosis. More often, however, therapy is directed against the infecting microorganisms by administration of drugs such as sulphonamide's or antibiotics.

While some of these substances kill the microorganisms, others do not and instead inhibit proliferation of the microorganisms and give host defences an opportunity to function effectively. For other infectious diseases there is no specific therapy. There are, for example, very few antiviral chemotherapeutic agents; treatment of viral diseases is mainly directed toward relief of discomfort and pain, and recovery, if it ensues, is largely a matter of an effective cellular immune response mounted against the invading virus by the host. From disease Major distinctions The normal state of an organism represents a condition of delicate physiological balance, or homeostasis, in terms of chemical, physical, and functional processes, maintained by a complex of mechanisms that are not fully understood. In a fundamental sense, therefore, disease represents the consequences of a breakdown of the homeostatic control mechanisms. In some instances the affected mechanisms are clearly indicated, but in most cases a complex of mechanisms is disturbed, initially or sequentially, and precise definition of the pathogenesis of the ensuing disease is elusive.

Death in human beings and other mammals, for example, often results directly from heart or lung failure, but the preceding sequence of events may be highly complex, involving disturbances of other organ systems and derangement of other control mechanisms. The initial cause of the diseased state may lie within the individual organism itself, and the disease is then said to be idiopathic, innate, primary, or 'essential. ' It may result from a course of medical treatment, either as an unavoidable side effect or because the treatment itself was ill-advised; in either case the disease is classed as iatrogenic. Finally, the disease may be caused by some agent external to the organism, such as a chemical that is a toxic agent.

In this case the disease is noncommunicable; that is, it affects only the individual organism exposed to it. The external agent may be itself a living organism capable of multiplying within the host and subsequently infecting other organisms; in this case the disease is said to be communicable. From disease Control of disease Prevention most diseases are preventable to a greater or lesser degree, the chief exceptions being the idiopathic diseases, such as the inherited metabolic defects. In the case of those diseases resulting from environmental factors, prevention is a matter of eliminating, or sharply reducing, the responsible material in the environment. Because these materials originate largely from human activities, prevention ought to be a simple matter of the application of well-established principles of industrial hygiene.

In practice, however, this is often difficult to achieve. The infectious diseases may be prevented in one of two general ways: (1) by preventing contact, and therefore transmission of infection, between the susceptible host and the source of infection and (2) by rendering the host unsusceptible, either by selective breeding or by induction of an effective artificial immunity. The nature of the specific preventive measures, and their efficacy, varies from one disease to another. Quarantine, which is an effective method of preventing transmission of disease in principle, has had only limited success in actual practice.

In only a few instances has quarantine achieved prevention of the spread of disease across international borders, and quarantine of individual cases of human disease has long been abandoned as ineffective. It has not been possible to prevent effectively the dissemination of airborne disease, notably airborne fungal diseases of plants and human diseases of the upper respiratory tract. Nor is disease ordinarily controllable by elimination of reservoirs of infection, such as those that occur in wild animals. There are certain exceptions in which the reservoir of infection can be greatly reduced, however; for example, chemotherapy of human tuberculosis may render individual cases noninfectious, and slaughtering of infected cattle may reduce the incidence of bovine tuberculosis. When infection is spread less directly, through the agency of living vectors or inanimate vehicles, it is often possible to break one or more of the links connecting the susceptible host with the source of infection. Malaria can be controlled effectively by the elimination of the mosquito vector, and louse-borne typhus in humans can be regulated by dis infestations methods.

Similarly, diseases spread in epidemic form through the agency of water or milk are controlled by measures such as the chlorination of public water supplies and the pasteurization of milk. Artificial immunization against certain diseases provides immunity and may be used in these instances, particularly when other methods of control are impractical or ineffective. The mass immunization of children in their early years has been highly effective in the control of diphtheria, smallpox, and poliomyelitis. Under special circumstances, as in certain military populations, it has been possible to control with prophylactic medicinal agents the spread of disease for which effective vaccines have not been developed. Sandy Gail now ski.