Aids to Health

The chapter begins by establishing the concept of health beyond the mere absence of disease, defining it as a state of complete physical, mental, and social well-being. It then differentiates between personal and community health, explaining how the latter focuses on maintaining the overall well-being of society. A key focus is on the body’s natural defense mechanisms, which are categorized into three lines of defense. The first line includes physical barriers like the skin and mucous membranes, along with chemical barriers such as lysozyme in tears and acid in the stomach. The second line of defense is the innate, non-specific immune response involving inflammation and fever, while the third and most sophisticated line is the adaptive immune system, which produces specific antibodies to combat particular pathogens and creates a lasting memory of them.

To bolster these natural defenses, the chapter details various aids to health, primarily immunization through vaccination. It explains how vaccines work by introducing a weakened or dead pathogen into the body, which stimulates the immune system to produce antibodies and memory cells without causing the actual disease. This prepares the body to fight off a future infection quickly and effectively. The significance of vaccination programs and the concept of herd immunity are also highlighted. Furthermore, the chapter introduces other crucial public health measures, including the maintenance of a safe water supply through methods like chlorination, proper sewage treatment to prevent waterborne diseases, and the scientific disposal of garbage to control vectors like flies and mosquitoes.

The discussion then moves to specific, widespread diseases to illustrate these principles. It covers the cause, transmission, symptoms, and prevention of major illnesses such as Typhoid, a water and food-borne disease; Tuberculosis (TB), an airborne bacterial infection; and Malaria, a vector-borne disease transmitted by the Anopheles mosquito. Understanding the life cycle of the malaria parasite is emphasized to explain preventive strategies like mosquito control. The chapter concludes by stressing that true health is a multifaceted goal, achievable through a combination of personal hygiene, a strong immune system, and robust, scientifically-managed public health services that work together to prevent the outbreak and spread of diseases within a community.

Multiple choice type

Question 1. 

Complete the following: Penicillin is an ______.

1. antibiotic
2. antianalgeric
3. Antipyretic

Question 2. 

Select the most appropriate option in each case.  ‘T’ in DTP vaccination stands for

1. Tuberculosis
2. Typhoid
3. Tetanus
4. Tonsillitis

3. Choose the correct answer: World Health Day is celebrated on _________

1. August 29   
2. January 30
3. April 7  
4. May 8

4. Select the most appropriate option in each case. DPT stands for

1. Diphtheria, Polio and Tetanus
2. Diphtheria, Pertussis and Tetanus
3. Dysentery, Polio and Typhoid
4. Diphtheria, Polio and Typhoid

5. Select the most appropriate option in each case. Vaccines are

1. An extract of toxins secreted by bacteria
2. An extract of dead and weakened microbes
3. Strong chemicals obtained from fungi
4. Chemicals that are applied on the skin to kill bacteria

Very short answer type

Question 1. 

1.Name the following: The drug based on arsenic compound, produced in 1910, which killed germs of syphilis.

2. Name the following: The antibiotic that was discovered first.

3. Name the following: The category of immunity required in the treatment of snake-bite.

4. Name the following: Any four antiseptics, any two disinfectants and any two antibiotics.

5. Name the following: The vaccine that helps to produce immunity against polio.

Ans:

Here are the names for the requested medical compounds and concepts:

1. The drug based on arsenic compound, produced in 1910, which killed germs of syphilis: Salvarsan (also known as Compound 606).
2. The antibiotic that was discovered first: Penicillin (Discovered by Alexander Fleming in 1928, first used clinically in the early 1940s).
3. The category of immunity required in the treatment of snake-bite: Artificial Passive Immunity (This involves injecting pre-formed antibodies, known as antivenom, directly into the patient).
4. Any four antiseptics, any two disinfectants and any two antibiotics:
   • Antiseptics (Used on living tissue): Iodine/Tincture of Iodine, Dettol (Chloroxylenol), Spirit (Alcohol/Ethanol), Hydrogen Peroxide
   • Disinfectants (Used on non-living surfaces): Phenol, Chlorine (Bleach/Sodium Hypochlorite), Formaldehyde, Sulphur Dioxide
   • Antibiotics (Used internally to kill bacteria): Penicillin, Streptomycin, Amoxicillin, Tetracycline (Any two from the full lists above are acceptable).
5. The vaccine that helps to produce immunity against polio: Oral Polio Vaccine (OPV) or Inactivated Polio Vaccine (IPV).

Question 2. 

1.Write the full forms of AIDS. 

2.Write the full forms of: BCG 

3. Write the full forms of: DPT vaccine 

4. Write the full forms of: WHO 

5. Write the full forms of: HIV 

6. Write the full forms of: ATS 

7. Write the full forms of: TAB 

8. Write the full forms of: STD

Ans:

Here are the full forms for the given acronyms:

1. AIDS: Acquired Immunodeficiency Syndrome
2. BCG: Bacillus Calmette–Guérin
3. DPT vaccine: Diphtheria, Pertussis (whooping cough), Tetanus
4. WHO: World Health Organization
5. HIV: Human Immunodeficiency Virus
6. ATS: Anti-Tetanus Serum
7. TAB: Typhoid, A and B (A vaccine against certain Salmonella typhi and paratyphi strains)
8. STD: Sexually Transmitted Disease

Question 3. 

Give the technical term for the kind of proteins produced in the blood to fight and destroy harmful mice

Ans:

The technical term for the kind of proteins produced in the blood to fight and destroy harmful microbes (assuming you meant microbes, as mice are large organisms not fought by proteins in the blood) is Antibodies (or Immunoglobulins).

These proteins are highly specific, meaning each type of antibody targets a specific pathogen or foreign substance (antigen).

Short answer type

Question 1. 

1.Mention if the following statement is true (T) or false (F). Lysol is an antibiotic. 

True

False

2. Mention if the following statement is true (T) or false (F). Sweat and tears contain germs-killing substances. 

True

False

3. Mention if the following statement is true or false: Our body can make only a limited variety of different antibodies.

True

False

4. Mention if the following statement is true or false: Salk vaccine is used against tuberculosis.

True

False

5. Mention if the following statement is true (T) or false (F). Treatment by the use of chemicals is known as allopathy.

True

False

6. Mention if the following statement is true (T) or false (F). Alexander Fleming coined the term ‘antibiotic’ for substances like penicillin. 

True

False

7. Mention if the following statement is true or false: DDT is a disinfectant.

True

False

8. Mention if the following statement id true (T) or false (F). Vaccine provides the body with active immunity.

True

False

9. Mention If the Following Statement is True (T) Or False (F). Penicillin was discovered by Alexander Fleming.

True

False

10. Mention if the following statement is true (T) or false (F).  BCG is the vaccine given to babies to help build immunity against three common diseases.

True

False

Ans:

Here are the evaluations for each statement:

1. Lysol is an antibiotic. False (Lysol is a disinfectant, used on surfaces to kill germs; antibiotics are medicines used inside the body to kill bacteria.)
2. Sweat and tears contain germs-killing substances. True (Tears and sweat contain the enzyme lysozyme, which is effective at breaking down the cell walls of certain bacteria.)
3. Our body can make only a limited variety of different antibodies. False (The immune system is capable of producing an almost infinite variety of different antibodies, each specifically designed to recognize and bind to a particular antigen.)
4. Salk vaccine is used against tuberculosis. False (The Salk vaccine is used against Poliomyelitis (Polio). The BCG vaccine is used against tuberculosis.)
5. Treatment by the use of chemicals is known as allopathy. False (Treatment by the use of chemicals is known as chemotherapy. Allopathy is the term traditionally used to refer to conventional, evidence-based modern medicine.)
6. Alexander Fleming coined the term ‘antibiotic’ for substances like penicillin. False (Alexander Fleming discovered penicillin in 1928. The term “antibiotic” was coined later in 1942 by microbiologist Selman Waksman.)
7. DDT is a disinfectant. False (DDT is a synthetic chemical used primarily as an insecticide (to kill insects), not a disinfectant (to clean surfaces).)
8. Vaccine provides the body with active immunity. True (Vaccines expose the immune system to antigens, causing it to produce its own antibodies and memory cells, which is the definition of active immunity.)
9. Penicillin was discovered by Alexander Fleming. True
10. BCG is the vaccine given to babies to help build immunity against three common diseases. False (BCG (Bacillus Calmette–Guérin) is a vaccine primarily used to build immunity against Tuberculosis (TB), a single disease. The DPT vaccine is the one used against three diseases (Diphtheria, Pertussis, Tetanus).)

Question 2. 

1.Differentiate between the following: Antiseptic and Antibiotics

2. Differentiate between the following: Disinfectant and Antiseptic

3. Differentiate between the disinfectant and deodorant

4. Differentiate between : Vaccination and sterilisation

5. Differentiate between : Active and passive immunity

6. Differentiate between: Innate immunity and acquired immunity

Ans:

1. Antiseptic and Antibiotic 

Feature	Antiseptic	Antibiotic
Usage	Applied externally to living tissues (skin, mucous membranes) to inhibit or kill microbes.	Taken internally (or sometimes topically) to kill or inhibit the growth of bacteria within the body.
Effect	General antimicrobial agents; kill or inhibit a broad range of microbes (bacteria, fungi, viruses).	Highly selective; primarily target and kill or inhibit bacteria (not effective against viruses).
Toxicity	Generally low systemic toxicity, but may irritate tissue.	Higher systemic toxicity; can have side effects and harm beneficial gut bacteria.
Example	Dettol, Iodine, Alcohol	Penicillin, Amoxicillin, Ciprofloxacin

2. Disinfectant and Antiseptic

Feature	Disinfectant	Antiseptic
Usage	Applied to non-living surfaces and objects (floors, equipment, furniture) to destroy microbes.	Applied to living tissues (skin, wounds) to inhibit or kill microbes.
Toxicity	Too toxic to be used safely on human tissues; high concentrations.	Low toxicity; safe for external application on tissues.
Goal	To achieve a high level of microbial destruction on inanimate objects.	To prevent infection and sepsis in open wounds or on skin surfaces.
Example	Bleach (Sodium hypochlorite), Phenol, Formaldehyde	Dettol, Surgical Spirit, Hydrogen Peroxide

3. Disinfectant and Deodorant 

Feature	Disinfectant	Deodorant
Function	To kill or inhibit the growth of microorganisms (pathogens).	To mask or neutralize unpleasant odors; often contains perfumes or odor-absorbing chemicals.
Effect on Microbes	Directly targets and destroys microbes.	Does not necessarily kill microbes; its primary function is olfactory (smell-related).
Example	Chlorine bleach on a countertop.	An air freshener or body spray.

4. Vaccination and Sterilisation 

Feature	Vaccination	Sterilisation
Goal	To confer long-term immunity against a specific pathogen by stimulating the body’s immune system.	To destroy all living microorganisms (including spores) on a surface or in a medium.
Mechanism	Involves introducing antigens (dead/weakened microbes) into the body to trigger antibody production.	Involves physical methods (high heat, pressure, radiation) or chemical agents to achieve total microbial destruction.
Application	Applied to living human/animal bodies for disease prevention.	Applied to inanimate objects or culture media (e.g., surgical tools, laboratory equipment).

5. Active and Passive Immunity 

Feature	Active Immunity	Passive Immunity
Source	Immunity is generated by the host’s own immune system (body produces its own antibodies).	Immunity is transferred via pre-formed antibodies from an external source (body does not produce its own antibodies).
Duration	Long-lasting (often lifelong), as memory cells are created.	Short-lived (lasts weeks or months), as antibodies are eventually degraded by the body.
Development	Slow development (takes days/weeks after exposure/vaccination).	Immediate effect; used when immediate protection is needed (e.g., snake-bite, tetanus exposure).
Examples	Getting a disease, receiving a vaccination.	Antibodies passed from mother to fetus (via placenta) or injection of antivenom.

6. Innate Immunity and Acquired Immunity

Feature	Innate Immunity	Acquired Immunity
Definition	The body’s non-specific, inborn defense system present from birth.	The body’s specific, adaptive defense system developed after exposure to antigens.
Specificity	Non-specific; reacts the same way to any pathogen.	Highly specific; targets and recognizes particular antigens.
Memory	No immunological memory; reaction is the same upon repeated exposure.	Develops immunological memory; subsequent reactions are faster and stronger.
Components	Physical barriers (skin, mucus), inflammation, phagocytic cells (macrophages).	B-cells (produce antibodies) and T-cells.

Question 3. 

Name any three vaccines and the diseases for which they provide immunity.

Ans:

Vaccine	Disease Prevented
BCG	Tuberculosis (TB)
MMR	Measles, Mumps, and Rubella
DPT / DTaP	Diphtheria, Pertussis (Whooping Cough), and Tetanus
IPV / OPV	Poliomyelitis (Polio)
Hepatitis B	Hepatitis B infection

Question 4. 

Given below is a table of certain vaccines, the diseases against which they are used and the nature of vaccines. Fill up the gaps 1-10. 

Vaccine	Disease(s)	The Nature of Vaccine
TAB	1. _______________	2. ___________________
Salk’s vaccine	3. _______________	4. ___________________
BCG	5. _______________	Living weakened germs
Vaccines for measles	Measles	6. ___________________
Cowpox virus	7. _______________	8. ___________________
Toxoids	9. _______________	Extracts of toxins
	10. ______________	Secreted by bacteria

Ans:

Vaccine	Disease(s)	The Nature of Vaccine
TAB	1. Typhoid (or Typhoid and Paratyphoid)	2. Killed/Inactivated Germs
Salk’s vaccine	3. Polio (Poliomyelitis)	4. Killed/Inactivated Germs
BCG	5. Tuberculosis (TB)	Living weakened germs
Vaccines for measles	Measles	6. Living weakened germs
Cowpox virus	7. Smallpox	8. Living weakened germs
Toxoids	9. Diphtheria and Tetanus	Extracts of toxins
DPT/DTaP	Diphtheria, Pertussis, Tetanus	10. Toxoids and Killed/Inactivated Germs

Clarifications on the Gaps:

• 1 & 2 (TAB): TAB stands for Typhoid and Paratyphoid. It uses Killed or inactivated bacteria.
• 3 & 4 (Salk’s): Salk’s vaccine (Inactivated Polio Vaccine or IPV) is used for Polio and consists of Killed virus.
• 5 (BCG): BCG stands for Bacillus Calmette–Guérin and is used for Tuberculosis.
• 6 (Measles): Most modern measles vaccines (like MMR) use a Living weakened (attenuated) virus.
• 7 & 8 (Cowpox): Edward Jenner used the Cowpox virus to successfully vaccinate against the structurally similar Smallpox virus. Cowpox is a Living weakened (relative to Smallpox) virus.
• 9 (Toxoids): Toxoids are specifically used against diseases caused by powerful bacterial toxins, such as Diphtheria and Tetanus.
• 10 (DPT/DTaP): The Diphtheria and Tetanus components are Toxoids, while the Pertussis component typically uses Killed or Inactivated bacterial fractions.

Question 5. 

1.Given below are the groups of certain substances of particular categories. Mention the category of group and identify the wrong example giving reason.  Lysol, benzoic acid, DDT, mercurochrome.

2. Given below are the groups of certain substances of particular categories. Mention the category of group and identify the wrong example giving reason. Formalin, iodine, lysol, phenol

3. Given below are the groups of certain substances of particular categories. Mention the category of group and identify the wrong example giving reason. BCG, DTP, ATP

4. Given below are the groups of certain substances of particular categories. Mention the category of each group and identify the wrong example giving reason. Tears, skin, nasal secretion, HCl (in stomach)

Ans:

Here are the analyses for each group of substances:

1. Lysol, Benzoic Acid, DDT, Mercurochrome

• Category of Group: Chemical Agents/Antimicrobial Agents (specifically, a mix of disinfectants, preservatives, and insecticides).
• Wrong Example: DDT
• Reason: Lysol (disinfectant), Benzoic acid (food preservative/antimicrobial), and Mercurochrome (antiseptic) are all chemical agents used to inhibit or kill microbes or protect organic matter. DDT (Dichlorodiphenyltrichloroethane) is an insecticide used to kill insects, not a compound primarily used to treat microbial infection or sanitize surfaces/food.

2. Formalin, Iodine, Lysol, Phenol

• Category of Group: Disinfectants and Antiseptics (Chemical substances used to destroy or inhibit microorganisms).
• Wrong Example: Iodine
• Reason: Formalin (a solution of formaldehyde), Lysol, and Phenol are most commonly used as disinfectants to sanitize inanimate surfaces and objects due to their toxicity. Iodine (or tincture of iodine) is primarily used as an antiseptic for application on living tissues (skin/wounds).

3. BCG, DTP, ATP

• Category of Group: Immunizing Agents/Biological Products (or substances related to infectious disease prevention, except for one).
• Wrong Example: ATP
• Reason: BCG (Bacille Calmette-Guérin) is a vaccine for Tuberculosis, and DTP is a combined vaccine for Diphtheria, Tetanus, and Pertussis. They are both biological products used for inducing immunity. ATP (Adenosine Triphosphate) is a high-energy molecule that serves as the energy currency of the cell; it is not a vaccine or an immunizing agent.

4. Tears, Skin, Nasal secretion, HCl (in stomach)

• Category of Group: Innate Immunity/First Line of Defense (Physical and chemical barriers that prevent pathogens from entering the body).
• Wrong Example: Skin
• Reason: Tears, nasal secretions, and HCl (hydrochloric acid) in the stomach are all chemical defenses (secretions) that contain protective enzymes or possess a hostile pH to destroy pathogens. The Skin is a physical barrier (a structural organ) and not a liquid secretion.

Question 6. 

Given below is a scheme of classifying immunity against human diseases. Fill up the types of immunity in the blanks 1-9.

Ans:

Number	Type of Immunity	Explanation
1	Innate	Also known as natural immunity; immunity present from birth.
2	Acquired	Developed over a lifetime in response to infections or vaccinations.
3	Specific	Immunity developed against a particular pathogen (e.g., measles).
4	Active	Immunity where the body’s own immune system produces antibodies.
5	Passive	Immunity received from an external source (not produced by the body).
6	Natural Active	Immunity developed naturally after recovering from an infection.
7	Artificial Active	Immunity developed through purposeful exposure (vaccination).
8	Natural Passive	Immunity passed naturally from mother to fetus via the placenta or milk.
9	Artificial Passive	Immunity achieved by injecting readymade antibodies (e.g., anti-tetanus serum).

Completed Immunity Scheme

1. Innate (Inborn/natural)
2. Acquired (Develops during life time)
3. Specific (For particular infections)
4. Active (Produced by one’s own body)
5. Passive (Supplied from outside sources)
6. Natural Active (By previous infections)
7. Artificial Active (by vaccinations)
8. Natural Passive (Antibodies received by fetus from mother’s blood)
9. Artificial Passive (Readymade antibodies produced in other animals)

Question 7. 

List any four ways in which the antibiotics are being used.

Ans:

Antibiotics are widely used in several sectors, mainly leveraging their ability to kill or inhibit the growth of bacteria.

Here are four major ways antibiotics are currently used:

1. Therapeutic Treatment of Bacterial Infections (Curative):
   • This is the primary use: treating individuals who have a confirmed or suspected bacterial infection (e.g., strep throat, urinary tract infections, pneumonia, or sepsis).
   • Antibiotics are administered orally, topically, or intravenously to eliminate the pathogenic bacteria and cure the disease.
2. Prophylactic Treatment (Preventive):
   • Antibiotics are given as a precaution to prevent bacterial infections in individuals who are at high risk, even before an infection is confirmed.
   • Examples include administering antibiotics before certain surgeries (like joint replacement or major dental procedures) to prevent wound infection, or giving them to immunocompromised patients (e.g., those with HIV or undergoing chemotherapy) to guard against opportunistic infections.
3. Animal Husbandry and Aquaculture (Livestock/Fish Farming):
   • Antibiotics are used in livestock and fish farming to treat sick animals and to prevent disease in herds or flocks where animals are kept in crowded conditions (prophylaxis).
   • Historically, they have also been used at low doses as growth promoters (though this practice is now restricted in many regions due to concerns about antibiotic resistance).
4. Horticulture and Agriculture:
   • Antibiotics like streptomycin and oxytetracycline are sometimes used to control bacterial plant diseases, such as fire blight in apple and pear orchards.
   • While less common than in human or veterinary medicine, this application helps protect crops from bacterial destruction.

Question 8. 

List the merits of local defense systems.

Ans:

The local defense systems (or innate/non-specific defenses) are the body’s first line of protection, acting immediately at the potential points of entry for pathogens, such as the skin and mucous membranes.

The merits of these local defense systems include:

• Speed and Immediacy: They provide an instantaneous defense to minimize initial damage to the body. Physical barriers (like intact skin) and chemical agents (like stomach acid) are always present and ready to act the moment a pathogen attempts entry.
• Non-Specificity/Broad Effectiveness: They are effective against a wide range of potential pathogens (bacteria, viruses, fungi, etc.) and foreign substances. They do not need to recognize a specific antigen, responding to all invaders with the same mechanism.
• Independence from Previous Exposure: The system is independent of any prior exposure to a specific microbe. Whether the body has encountered the germ before or not, the local barriers and internal mechanisms (like phagocytosis and inflammation) launch their attack immediately.
• Mechanical Barriers: They act as protective mechanical barriers to physically stop entry. Examples include the skin, the cilia of the respiratory tract that sweep mucus out, and the flushing action of urine and tears.
• Chemical and Biological Warfare: They secrete germ-killing fluids and substances that inhibit microbial growth or destroy the microbes directly. Examples include the low pH (acidity) of the stomach and skin, and the enzyme lysozyme found in tears and saliva.

These systems are crucial because they restrict the initial multiplication of pathogens to manageable levels, giving the specific (adaptive) immune system time to mobilize and launch a targeted response.

Question 9. 

Suppose a person develops the disease diphtheria. Comment upon the principle of the treatment he should receive.

Ans:

If a person develops the disease Diphtheria, the treatment principle should involve administering Artificial Passive Immunity immediately.

Principle of Treatment

The treatment principle is based on counteracting the toxin produced by the Corynebacterium diphtheriae bacteria, which is the primary cause of the severe symptoms and mortality associated with the disease.

1. Immediate Neutralization: The patient is given an injection of Diphtheria Antitoxin (DAT). This antitoxin consists of pre-formed antibodies (Immunoglobulins) derived from an external source (usually horses).
2. Passive Immunity: This grants Artificial Passive Immunity, providing an immediate, high level of protection. Since the antibodies are already made, they instantly circulate in the blood and bind to and neutralize the bacterial toxins circulating in the patient’s system.
3. Active Treatment: Along with the antitoxin, the patient must also be given antibiotics (like penicillin or erythromycin) to kill the active C. diphtheriae bacteria in the throat, preventing them from producing more toxin.

Long answer type

Question 1. 

The principle of vaccination is to produce immunity against a disease. Explain.

Ans:

The principle of vaccination is to safely stimulate the body’s active immunity against a specific disease without causing the illness itself.

How Vaccination Works 

Vaccination works by introducing an antigen—a molecule capable of eliciting an immune response—into the body. This antigen comes from the pathogen but is delivered in a weakened, dead, or fragmented form (the vaccine).

1. Antigen Presentation: Once the vaccine is administered, specialized immune cells (like antigen-presenting cells) recognize the foreign antigen.
2. Immune Response: These cells then present the antigen to T-cells and B-cells. The B-cells activate, rapidly multiply, and transform into plasma cells, which begin producing vast quantities of specific antibodies tailored to neutralize that exact pathogen.
3. Memory Formation: Crucially, some of the activated B-cells and T-cells remain behind as memory cells. These cells do not produce antibodies immediately but stay dormant in the body for months or years.

The Result: Immunity

If the vaccinated person is later exposed to the actual, active pathogen, the memory cells immediately recognize the antigen. This triggers a rapid and massive secondary immune response—producing antibodies far faster and in greater amounts than the initial (primary) response.

Because the body can neutralize the pathogen quickly before it has a chance to multiply significantly and cause damage, the person is protected from developing the disease. This protection is what is known as immunity.

Question 2.

”Abnormally, large numbers of WBCs in the blood are usually an indication of some infection in our body”. Comment on the statement.

Ans:

The statement, “Abnormally, large numbers of WBCs in the blood are usually an indication of some infection in our body,” is generally True and reflects a critical principle of the body’s immune response.

Why High WBC Count Indicates Infection

1. The Role of WBCs (Leukocytes)

White Blood Cells (WBCs) are the primary cells of the immune system, responsible for defending the body against foreign invaders (pathogens) such as bacteria, viruses, fungi, and parasites.

2. Leukocytosis (Increased Production)

When an infection occurs, the body’s control centers (like the bone marrow) are signaled to dramatically increase the production and release of WBCs into the bloodstream. This condition is called leukocytosis.

3. Fighting the Pathogen

The large number of WBCs travel to the site of infection where they perform various defensive functions, including:

• Phagocytosis: Certain WBCs (like neutrophils and macrophages) engulf and digest the invading microbes.
• Antibody Production: Lymphocytes produce antibodies to neutralize pathogens.

Therefore, finding an abnormally high WBC count during a routine blood test is a strong clinical indicator that the body’s immune system is actively mobilized to fight an ongoing infection (or sometimes, other conditions like inflammation or leukemia).

Question 3. 

1.Explain briefly, the role of the following health aids: Antiseptics 

2. Define the following : Disinfectants

3. Define the following: Vaccine

Ans:

Here are revised explanations for the requested health aids and terms, focusing on distinct and original phrasing:

1. Role of Antiseptics 

The primary function of an antiseptic is to serve as a topical chemical agent used to control microbial populations on living tissues. By inhibiting the proliferation or destroying microorganisms on the skin, mucous membranes, or open wounds, antiseptics play a crucial role in preventing localized infection and sepsis when the body’s natural physical defenses are compromised. Their formulation is specifically designed to be safe for application to biological surfaces.

2. Disinfectants 

A disinfectant is a powerful antimicrobial chemical or physical treatment (such as strong heat or chemical solutions like bleach) employed to eliminate or deactivate nearly all pathogens and microbes on non-living environmental surfaces. The key distinction is that disinfectants are typically highly potent and unsafe for use on the body due to their toxicity to human cells, making them strictly reserved for cleaning instruments, floors, and other inanimate objects.

3. Vaccine 

A vaccine is a preparatory biological substance crafted to safely mimic a disease-causing agent, thereby inducing a protective immune response within the host. It works by introducing antigens (derived from weakened, killed, or fragmented pathogens) into the body. This process tricks the immune system into recognizing the threat and manufacturing specific antibodies and immunological memory cells, ensuring the body is prepared for a rapid and effective defense should it encounter the actual disease later.