Basal lamina - a term used to describe the different layers which make up the basement membrane1. These different layers of the basement membrane, the lamina lucida and lamina densa are only visible with electron microscopy. Into the lamina dense collagen fibres of the lamina propria are anchored. And on the epithelial side are anchored bundles of tonofilaments from the hemi-desmosomes which anchor the basal epithelial cells to the basement membrane.

Basement membrane - a thin sheet of proteins held together by type IV collagen. On this sheet epithelial cells attach with hemi-desmosomes. All epithelia, whether simple cuboidal cells such as found in the salivary glands, or endothelial cells lining capillaries or thick stratified squamous epithelia of the skin, are all anchored to a basement membrane.

Benign- not harmful. In the sense of tumours, not malignant. When referring to parasites, quite harmless.

Biofilm - a layer of microorganisms on a surface which is kept constantly wet. Dental plaque is an oral biofilm

Biosurfactants - products of bacteria which increase the hydrophilic nature of a surface so as to allow for better adhesion.

Blood clotting - one of three key processes in haemostasis, the prevention of blood loss. After three minutes of rupture of a small blood vessel, the entire cut is filled with a blood clot. After an hour, the clot has retracted inside the vessel making the plug even more effective. Within a few more hours, fibroblasts have moved into the clot, followed by capillary -forming endothelial cells. Within 10 days the clot is replaced by fibrous scar tissue. Clotting takes place in three steps. 1. In response to damage to the blood vessel prothrombin activator is formed. 2 this activator converts prothrombin into thrombin. 3.The thrombin acts as an enzyme18 converting fibrinogen into fibrin threads which adhere to the damaged walls of the blood vessel, trap platelets, blood cells and plasma to form a clot.