IB Biology SL - Topic 6: The Immune System

Prokaryotes that divide via binary fission; can cause food poisoning, ear and eye infections, cholera, and diarrhea

Eukaryotes that reproduce via spores; can cause athlete's foot, allergic reactions, and respiratory problems

Acellular and non-living organisms that need a host to carry out the functions of life; can cause flu, HIV, smallpox, measles, common cold, herpes, ebola, etc

Simple parasites; can cause malaria, leishmaniasis, and toxoplasmosis

Inhaled droplets, direct contact, bodily fluids, animal vectors, ingestion

First line of defense; trap invaders, pH is not favorable to pathogens, lysozome enzymes break down pathogens, natural organisms provide competitive exclusion

First line of defense; continuous and tough, dry, pH is not favorable to pathogens, lysozomes in sweat break down pathogens, natural organisms provide competitive exclusion

Solid parts of the blood that aid in blood clotting

Proteins that help to stop bleeding via creating blood clots

Protein which forms a mesh of fibers across open wounds; activated after outside exposure

Chemical that converts fibrinogen (soluble in blood) to fibrin (not soluble)

Degenerative disease where fibrous tissue grows in the damaged areas of artery walls; build-up of cholesterol forms plaques which leads to a loss of elasticity, narrowing the lumen and restricting blood flow

Blood clot forming in the blood vessels of the heart, caused by the rupturing of built-up plaque

Non-specific; skin, mucous membranes, secretions of skin and mucous membranes

Non-specific; phagocytic leukocytes, antimicrobial proteins, inflammatory response, fever

Acquired and specific; lymphocytes, antibodies, memory cells

Chemical produced by leukocytes (basophils and mast cells) which aids in the inflammatory response

Hives, itching, capillary permeability; overreaction may cause allergies

Molecule recognized as foreign by the immune system, being treated as a foe; outlines the surface of cells

Labels the body's cells as 'friend' and are tolerated by the immune system

White blood cells which attach to pathogens' cell surfaces and engulf them

Movement in response to chemicals

Vesicle within the phagocyte which forms when the pathogen has been engulfed; contains it and lysosomes deposit enzymes to break it down

The process of endocytosis utilized by phagocytes

A disease or infection that is naturally transmissible from vertebrate animals to humans; e.g. ebola and salmonella

Process in the third line of defense in which antibodies are produced

Cells to which antigens on the surface of phagocytes (after phagocytosis) bind to; activates B-cells

Cells which divide to produce plasma and memory cells

Produce antibodies specific to an invader

Remember invaders for future recognition; allows for the development of immunity, particularly in vaccination

Chemicals used for cell activation between Helper T-cells and B-cells

Immunoglobulins; proteins produced by plasma cells which mark invaders due to their antigens, triggering an immune response

Part of the Y-shaped antibody; variable and specific to an antigen's epitope

Makes soluble antigens insoluble, aiding in their elimination via phagocytosis

Links cell-bound antigens together, causing clumping which aids in elimination via phagocytosis

Marks dangerous parts of the pathogen (e.g. exotoxins) which aids in elimination via phagocytosis

Triggers histamine release, increasing immune mobility which aids in elimination via phagocytosis

Protein perforates the cell membrane and leads to cell lysis (breaks open the cell, killing the pathogen)

Production of own antibodies due to natural or artificial (vaccine) exposure

Ready-made antibodies due to maternal antibodies or other sources (e.g. rabies treatment)

Genetic immunity

Development of immunity through the third line of defense

Allows for individuals to become immune to a disease without experiencing it

Initial immune response to a vaccine; body is presented with inactive virus or antigens

Medicine which combats prokaryotic bacteria by disrupting structures and metabolic pathways; e.g. penicillin

Antibiotic derived from the fungus S. aureus; discovered by Fleming and supported by Florey & Chain

Human Immunodeficiency Virus; gradually attacks the immune system by damaging Helper T-cells; can lead to AIDS

Caused by HIV; the immune system is too weak to fight off infection, eventually leading to death by opportunistic diseases; diagnosed when there is 200 Helper T-cells per mm3