Unit 4 AOS1 biology

What is disease

Anything that impairs the normal function of a cell/organism

What is an infectious disease

A disease that can be transmitted between organisms. e.g through the air, water droplets

What is a pathogen

A disease causing agent

What is a prion and give an example

A type of pathogen that stems from misfolded proteins. eg Mad cows disease, Kuru

What is an antigen

Any molecule that may trigger an immune response

What is a self molecule

Cell, tissue, molecules that have markers that are belonging to self

What is a non self molecule

Cellular molecule that are recognized as foreign.

What is a self antigen

Located on the surface of cells. these molecules are called MHC

What is MHC 1

A molecule expressed on all nucleated cells in the body. They mark cells as self so that the immune system doesn’t attack them.

What is MHC 2

Found on white blood cells in particular phagocytes ( dendritic cells, macro phages and B cells).

What is an auto immune disease

A failure of the immune system to identify self cells. Therefore the immune system attacks self cells.

What is an allergen

Anything that can cause an allergic reaction

What is an allergic reaction

An over reaction of our immune system to something that is not normally considered harmful.

What is an inflammatory response

A response caused by the release of histamine from most cells, damaged tissues.

The histamine signals vasodilation that increases blood flow to the region leading to swelling and other symptoms.

What are examples of pathogens

Bacteria, protozoans, fungal, virus, prions