Human Health: Infectious Diseases and Body Defence Mechanisms

Flashcards covering key vocabulary and definitions related to infectious and non-infectious diseases, disease transmission, and the body's defence systems.

Disease

An abnormal condition of body or mind that causes discomfort, difficulty to function or stress to an individual.

Infectious disease

Caused by infection of pathogens directly through mediums and vectors; can be transmitted from one individual to another.

Non-infectious disease

Caused by genetic factor or lifestyle; cannot be transmitted from one individual to another.

Pathogens

The organisms that cause diseases, including viruses, some bacteria, protozoa, fungi, and worms.

Droplet transmission

Transmission via pathogen-containing droplet sprays from the mouth and nose of an infected person.

Dust transmission

Transmission via bacteria in the spit of an infected person that dry up and form spores spread with dust in the air.

Waterborne diseases

Infection through contaminated water, often in areas with inadequate water supply and poor sanitation.

Infection of diseases through contact

Diseases transmitted through direct physical contact with an infected person or contaminated items.

Vectors

Animals that transmit pathogens from one host to another.

Pathogen for Cockroach and Fly

Salmonella typhi

Pathogen for Aedes mosquito

Zika virus

Pathogen for Aedes mosquito

Dengue virus

Pathogen for Anopheles mosquito

Plasmodium malariae

Pathogen for Rat

Leptospira sp. bacteria

Primary stage of preventing infectious diseases

Improving personal hygiene, strengthening the body's defense system through vaccines, and maintaining a healthy lifestyle.

Secondary stage of preventing infectious diseases

Determining transmission through case detection and giving early treatment to patients.

Tertiary stage of preventing infectious diseases

Controlling vector populations and protecting hosts by using mosquito nets or coils.

First line of defense

Prevents pathogens from entering the body.

Second line of defense

Fights pathogens through phagocytosis.

Third line of defense

Fights pathogens by producing antibodies.

Skin

A tough layer that is difficult to be penetrated by microorganisms; secretes sweat and sebum that can kill microorganisms.

Mucous membrane

Membrane lining the digestive and respiratory tracts that traps microorganisms; secretes antiseptic fluids like earwax and tears.

Phagocytosis

White blood cells engulf and digest pathogens using enzymes.

Antibody

A protein produced by white blood cells in response to antigens.

Antigen

A foreign substance that comes from outside the body and induces the production of antibodies.

Immunisation

An effort to stimulate the body defence against infections by injecting vaccines.

Vaccine

Contains antigens from a weakened or dead virus or bacterium to stimulate the body's immune system.

Passive immunity

The body gains antibody from external sources.

Active immunity

The body produces its own antibodies when stimulated by antigens.

Passive natural immunity

Obtained when a baby receives antibodies from breast milk or the mother's blood; temporary immunity.

Passive artificial immunity

Obtained when an antiserum is injected into the patient's body; fast and temporary immunity.

Active natural immunity

Occurs when a person recovers from an infection; immunity lasts long after the infection.

Active artificial immunity

Occurs when a vaccine is injected, and the immune system responds by producing antibodies; long-lasting immunity.