Review of Lecture Notes on Pathogens, the Immune System, and Related Diseases

Flashcards covering key vocabulary from lecture notes on pathogens, the immune system, and related diseases for exam preparation.

Germ Theory

The idea that microscopic particles (pathogens) cause certain diseases.

Pathogen

A microorganism or agent that causes disease.

Vector

Any agent (often an insect) that carries and transmits a pathogen.

Infectious disease

Disease caused by germs; can be passed from person to person (e.g., flu, polio).

Noninfectious diseases

Diseases not caused by germs; cannot be passed (e.g., cancer, heart disease); often due to genetics or lifestyle.

Bacteria

Single-celled organisms that cause illness by releasing toxins or destroying cells.

Viruses

Strands of DNA or RNA with protein coats that take over healthy cells to replicate; cause flu, cold, AIDS.

Fungi

Single-celled or multicellular organisms that invade cells and steal nutrients; thrive in warm, damp environments (e.g., athlete’s foot).

Protozoa

Single-celled organisms that prey on other cells and require host cells for part of their life cycle (e.g., Malaria).

Parasites

Organisms that live in/on a host, feeding off it and potentially killing or weakening it (e.g., filaria).

Immune System

Body system that fights infection and pathogens.

Phagocyte

A white blood cell that engulfs and destroys pathogens.

T cell

Lymphocyte that destroys infected body cells.

B cell

Lymphocyte that produces proteins (antibodies) to inactivate pathogens.

Antibody

Protein made by B cells that destroys or inactivates pathogens.

Interferon

Protein released by virus-infected cells to help other cells resist viral infection.

Passive Immunity

Immunity acquired without an immune response (inherited or transferred).

Active Immunity

Immunity developed through an immune response to a pathogen.

Antigen

Protein marker on the surface of cells/viruses used to identify foreign entities.

Memory Cell

Specialized T and B cells that remember a pathogen for faster future responses.

Cellular Immunity

Immune response involving T cells destroying infected cells.

Humoral Immunity

Immune response involving B cells producing antibodies.

Inflammation

A nonspecific immune response causing swelling, redness, warmth, pain, and itching.

Tissue Rejection

Immune response where the body attacks transplanted foreign tissue.

Antiseptic

A chemical substance (e.g., soap, vinegar, rubbing alcohol) that kills pathogens outside the body.

Antibiotic

A medicine that kills or stops the growth/reproduction of bacteria or fungi.

Antibiotic Resistance

When bacteria mutate to survive antibiotic treatment.

Vaccine

A substance containing antigens that helps the body develop immunity without causing illness.

Allergy

An oversensitivity of the immune system to a normally harmless antigen.

Allergen

An antigen that causes an allergic reaction.

Anaphylaxis

A severe allergic reaction in which the immune system releases a large amount of histamine, leading to airway tightening and leaky blood vessels.

Leukemia

Cancer of the bone marrow that results in the production of abnormal, immature white blood cells.

Opportunistic Infection

An infection caused by a pathogen that a healthy immune system would typically defeat.

HIV

A retrovirus that attacks and weakens the immune system by infecting T cells.

AIDS

The final and most severe stage of HIV infection; occurs when the immune system becomes extremely weak and vulnerable to opportunistic infections.