Immune system

Task 1 Learn the following words and word combinations:

immunity – імунітет

Man has natural immunity to some diseases.

exhibit – виявляти, показувати

Certain individuals exposed to an infectious agent may fail to contract the disease or to exhibit as severe the case as others.

inherited – успадкований

Certain types of resistance are inherited by the individuals possessing them.

inborn resistance – вроджений опір

Various types of inborn, inherent resistance may be termed natural immunity.

miscellaneous – змішаний, різноманітний

Antigens may also come from animals, plants, foods, and miscellaneous materials.

Task 2 Form the new words adding the prefixes un- or non-. Translate the words.

Model: armed – unarmed – неозброєний

natural – unnatural – неприродний

infective – noninfective – неінфекційний

affected, altered, anesthetized, broken, complicated, conditioned, conscious, contaminated, cured, delivered, cooled, crystallized, infected, absorbed, immune.

Task 3 Analyze the structure of the following terms:

immunization, antiserum, anaphylaxis, anaphylactoid, rickettsial, attenuation, fertile, disintegration, agglutinate, neutralize.

Task 4 Match the following English word combinations with the Ukrainian ones:

1 harmless toxoid a)рідкісний виняток

2 rare exception b) токсична дія

3 toxic effect c) активна імунізація

4 active immunization d) алергічна реакція

5 allergic reaction e) нешкідливий токсоїд

Task 5 Find substitutes for the following word combinations:

1 A specific substance produced in the organism as a reaction to the presence of an antigen.

2 Counteracting anemia.

3 Altered toxin.

4 Useful in curing or preventing the action of harmful bacteria.

5 Therapeutic application of low temperature.

a) toxoid; b) antibody; c) antibacterial; d) refrigeration; e) antianemic.

Task 6 Put in the missing words from those given below:

1 Some medical preparations are kept under … .

2 Vaccines are injected or ingested for the production of active… .

3 Toxins may be … and made inert.

4 One molecule of … combines with one molecule of antibody.

5 Acquired immunity may come about through natural processes which may follow … to the infectious agent.

a) neutralized; b) antigen; c) exposure; d) immunity; e) refrigeration.

Task 7 Form new words by adding the prefixes. Define the part of speech and translate them:

1. dis:coloration, continue, like, appear;

2. un:natural, cured, cooled, conscious, treated;

3. over:use, strain, work, eating, dosage;

4. intra:venous, muscular, cellular, vascular/

Task 8 Skim through the text and define its main subject.

Man is susceptible to infection only by certain microorganisms present in the world and has a specific immunity to others that attack animals and other forms of life. Some races of men are less susceptible to certain specific infectious agents than others. For example, Caucasians exposed to tuberculosis for many centuries, are appreciably more resistant to the disease than Afro-Americans and American Indians. This is an example of partial racial immunity. In addition, certain individuals exposed to an infectious agent even in an epidemic or endemic, may fail to contract the disease or to exhibit as severe a case as others. Thus, there is an individual immunity to many diseases affecting man. These various types of inherent, inborn resistance may be termed natural immunity. They are inherited by the individuals possessing them. When natural immunity is present the tissues and circulating blood of the host or the intended host are not conductive to successful invasion by the infectious agent, or to the same degree as those of another host.

In addition to any natural resistance to specific diseases which individuals may possess, they may acquire partial or complete protection against certain infectious disease. Such acquired immunity may come about through natural processes which may follow exposure to the infectious agent, whether overt disease accompanies the exposure or not. As a result of the subclinical or overt disease, substances may be produced within the body that can repel or moderate a subsequent attempted invasion by the same organism. Some of these substances may remain upon or within the wall of certain cells, and others may circulate in the tissue fluids and plasma.

They can be demonstrated in the serum after clotting separation of the serum from the contracted clot. They are known as antibodies, materials which are usually highly specific against invading organisms or their products. Antibodies are proteins made by certain cells of the host in response to the presence of foreign substances known as antigens. The latter may be the invading agents of infectious disease or chemicals derived from them. Antigens may also come from animals, plants, foods, and miscellaneous materials.

The antibodies against infectious agents produced by some individuals or by animals may be concentrated and administered to patients for combatting an infection. The use of antibodies constitutes passive immunization wherein the protective material, specific for a given infectious agent or group of closely related agents, is produced in another individual or animal and given thus “ready-made” to the patient.

Antiserum. The protective antibodies explained above in most cases are present in the serum of the animal or person who has produced them. Animals are repeatedly given small or increasing amounts of the particular antigen or infectious agent whereupon they may develop considerable quantities of antibodies, usually antitoxins. Administration of these antibodies in antisera provides immediate passive immunity in various diseases. They may abruptly improve the course of the disease process. They may also cause undesirable reactions such as allergic responses, anaphylaxis, anaphylactoid reactions, and serum sickness. In most cases the antibodies administered in antisera do not reside indefinitely in the recipient, or even for a year in some.