Primary/First line of defence (Non Specific)

• Skin; keratinised layer of dead cells forms an effective barrier and acts as main primary defence
• Mucous membranes (gut, genital areas, anus, ears and nose) have ciliated epithelium and goblet cells, secretions (stomach acid, lysozyme, antibodies in tears and ear wax)
• Blood clotting involving an enzyme cascade of 1 clotting factors and calcium ions which are all released from platelets (thrombocytes) and the damaged tissue cells
• Expulsive forces; triggered by presence of microbes or a secreted toxin (sneezing, vomiting and coughing); enables the body to get rid of potentially harmful microbes