Pathogens and the Immune System

Vocabulary flashcards covering the biological characteristics of pathogens (bacteria, viruses, parasites, prions), the unspecific and specific immune responses, immunization methods, and antibiotics.

Infection

The transmission of a disease by another living organism.

Pathogens (Krankheitserreger)

Organisms and agents that cause disease, categorized into viruses, bacteria, parasites (fungi, worms, single-celled organisms), and prions.

Prions

Disease-causing proteins.

Beneficial Bacteria

Non-pathogenic bacteria in humans that digest dietary fiber, positively influence the immune system in the gut, or combat pathogens on the skin.

Bacterial Pathogenicity

The mechanisms by which bacteria cause disease, specifically through producing enzymes that destroy human cells to use as nutrition and releasing toxic excretions that damage human cells.

Virus Structure

Extremely small biological entities that consist of genetic material ($\text{DNA}$ or $\text{RNA}$) enclosed in a protein coat, lacking organs, cytoplasm, independent metabolism, and self-reproduction.

Viral Reproduction

The process whereby a virus docks onto a host cell, injects its genetic material, reprograms the host cell to mass-produce viral components and assemble daughter viruses, and destroys the host cell upon release.

Unspecific Immune System

The general defense mechanism that combats all pathogens without exception through anatomical barriers, phagocytic defense cells, and blood reactions such as fever and inflammation.

Granulocytes

Defense cells that act as scavenger cells (phagocytes) within the unspecific immune system.

Macrophages

Giant phagocytes (Riesen-Fresszellen) of the unspecific immune system that ingest pathogens and present fragments with antigens to summon T helper cells via hormone secretion.

Antigens

Recognition proteins situated on the surface of cells.

T Helper Cells

Specific T-lymphocytes that match a presented antigen, proliferate extensively via cell division, and activate matching B-lymphocytes and T-killer cells.

Plasma Cells

Activated B-lymphocytes that mass-produce specific antibodies to clump pathogens for phagocytosis.

T Killer Cells

Specific T-lymphocytes activated according to the lock-and-key principle (SSP) that kill and eliminate infected body cells.

Memory Cells

A subpopulation of T- and B-lymphocytes that circulate in blood and lymph over long periods, triggering an immediate immune response upon reinfection so that the disease does not break out.

Active Immunization

A preventive vaccination (Schutzimpfung) using dead or fragmented pathogens that triggers a mild immune response and creates lifelong memory cells.

Passive Immunization

The administration of lab-manufactured antibodies after disease diagnosis when the body lacks specific antibodies; it offers short-lived immunity and does not provide permanent protection.

Antibiotics

Medications that fight bacteria by puncturing cell walls/membranes, blocking vital proteins, and preventing $\text{DNA}$ replication and cell division.

Antibiotic Resistance

The selection and survival of mutated bacteria against an antibiotic, often accelerated by premature discontinuation of prescribed treatment or overuse in factory farming feed.