Topic 2: Cells : Antigens and the immune system

What is a disease?

A persistent deviation from a person's usual appearance ,body function or behaviour

Communicable (or infectious) diseases

Those that can be passed from one organism to another. They are caused by microorganisms known as pathogens

Helminths

Parasitic worms e.g. Flutes, roundworms and tapeworms. Tend to live in the gastrointestinal tracts. Release microscopic eggs which excreted in faeces which contaminate water and soil to spread

Plasmodium (malaria causing Protozoa)

Spreads when mosquito drinks blood. Destroys red blood cells. Carried by female mosquitoes (vectors)

Fungi

Airborne or contaminated food e.g. Athletes foot, ringworm

Prions (acellular - proteins)

Causes incorrect folding of proteins, very progressive especially in nervous system, spread by concerning infected tissue

How do bacteria cause disease?

Produce toxins that damage body cells

How do viruses cause disease?

Use host cells to replicate before bursting out and destroying cells.

How do Protoctists cause disease?

Take over cells and break them open

How do fungi cause disease?

Digest living cells to destroy them and some produce toxins