专业术语—口腔生理学术语P5(英文详解)（在线收听）

    Prostaglandins - are members of a class of hormones known as the eicosanoids. They are released by cells which have been damaged and have a powerful ability to sensitise nerve endings causing tenderness to the damaged area, and to cause vasoconstriction by contracting the smooth muscle of arterioles. They belong to a group of compounds which have a similar effect on nervous tissue, known asneuropeptides.

    Proteins - usually very large molecules, from 10,000 to 200,000 amino acids, which form the structural component of a cell'smatrix. and cytoskeleton. All enzymes are proteins.

    Proton - the positively charged elements of the nucleus of an atom. A hydrogen atom without its electron amounts to a single proton charge.

    Pulp - the dental pulp is a connective tissue trapped inside the fully formed tooth with just one entry and exit for nerves and vessels, at the apex of the root. The characteristic cell of the pulp, is the odontoblast, which lines the walls of the pulp chamber and is able to form dentine throughout life.

    Pulpitis - inflammation of the dental pulp caused by irritation from chemical, physical or bacterial injury, usually transmitted to the pulp via the dentine. It is important for the clinical management of the tooth, to decide whether the pulpitis is reversible, that is will it resolve if the irritation is removed, or whether it has been damaged beyond its capacity to repair.

    Pyrophosphate - inhibitors of mineralisation, they may offer up phospate ions in the presence of alkaline phosphatase. Crystals of calcium pyrophosphates are found in abnormal calcification of soft tissue, such as the disc of the TM Joint.