Causes
Any organism or agent that causes infectious disease.
What is a pathogen?
The skin, mucous membranes and stomach acid are part of this line of defence.
What is the first line of defence (innate, non-specific)?
Increased permeability of capillaries lets fluid leak into the tissue, causing this sign.
What is swelling?
Separating people who may have been exposed to a disease from the healthy population is called this.
What is quarantine?
Misfolded proteins that cause diseases such as Creutzfeldt-Jakob disease and kuru.
What are prions?
These white blood cells, including macrophages and neutrophils, engulf and digest pathogens.
What are phagocytes?
A molecule, usually a protein on the surface of a pathogen, that triggers an immune response.
What is an antigen?
When a large proportion of a population is immune, non-immune individuals are indirectly protected. This is called this.
What is herd immunity?
These require that the pathogen from a pure culture, when introduced into a healthy host, causes the same disease.
What is Koch's Postulates?
Released by damaged cells during inflammation, this chemical causes vasodilation and increased blood flow to the site.
What is histamine?
These Y-shaped proteins, produced by plasma cells (B cells), bind to specific antigens.
What are antibodies?
Antibiotics are effective against this type of pathogen but not against viruses.
What are bacteria?
Spread of a pathogen by touching, kissing or sexual contact is called this type of transmission.
What is direct contact?
This enzyme, found in tears and saliva, breaks down bacterial cell walls.
What is lysozyme?
These T cells destroy body cells that have been infected by a pathogen.
What are cytotoxic T cells?
Overuse of antibiotics selects for bacteria with this trait, as seen in MRSA.
What is antibiotic resistance?
Anopheles mosquitoes carry the malaria pathogen between hosts, making them an example of this.
What is a vector?
These hair-like structures line the airways and sweep trapped pathogens upward.
What are cilia?
Damaged cells and phagocytes release these signalling molecules, which attract more immune cells to the site of infection.
What are cytokines?
An outbreak of disease that spreads across multiple countries or continents.
What is a pandemic?