primary non specific animal defences

• the skin acts as a physical barrier again pathogens
• blood clots form when there is a cut on the skin and it form a new barrier
• mucous membranes line the body's tracts and produce mucous to trap pathogens, the cilia then move the mucous away from the lungs
• lysozymes are hydrolytic enzymes which digest pathogens
• expulsive refluxes are mechanisms that force the pathogen out the body for example coughing and sneezing
• inflammation occurs in a localised area of damage and causes area to become hot red sore itchy and swollen
• when cells are damaged this triggers mast cells to release histamines and cytokines
• histamines cause blood vessels to dilate much more blood flow to the damaged area increasing the temperature killing the pathogen
• histamines make the cell wall more permeable meaning more white blood cells can enter the area of damage
• cytokines attract phagocytes that engulf and destroy pathogens
• process of blood clotting and formation of scab