Immunology- Innate Immunity

• Immune System

Immunity is mediated by the immune system

The Immune system responds to infection by mouting an immune response

An immune response must: Recognise a pathogen as foreign, respond and mediate elimination of the pathogen

Microorganisms are ubiquitous

Resistance to invasion is a characteristic which is present from birth, known as innate immunity.

Innate Immunity Present from birth  Non-specific- It acts on many organisms and does not show specificity It does not become more efficient on subsequent exposure to the same organisms

• Prevention of entry organisms

Mechanicals barriers: 1. Skin; most bacteria fail to survive on the skin because of lactic acid and fatty acids in sweat- low pH 2. Mucous secreted by membrane; Protective barrier that blocks adherence of bacteria to epithelial cells; foreing particles trapped in mucous are cleared by ciliary movement, coughing and sneezing

Washing action of tears, saliva and urine Anti-bacterial substances in secretions Low pH of stomach contents Lysozyme Lactoferrin

Microbial Antagonism- where the normal bacteria of the body…