（单词翻译:单击）
Epidermal1 growth factor - a cytokine that stimulates2 epithelial cell proliferation.
Epinephrine - a neurotransmitter substance found at all adrenergic synapses3 (nor epinephrine or epinephrine). It is the most common neurotransmitter in the nervous system, in particular at ganglion cells of the sympathetic nervous system.
Epitaxy - the initiation4 of crystalformation in a saturated5 solution by providing a template against which crystal can form. There are specific sites on collagen molecules6 which appear to function as templates against which hydroxyapatite crystals form.
Epithelial attachment7- the cuff8 of junctional epithelium which joins the gingival sulcus epithelium to the enamel9 of the tooth. Apical migration10 of the epithelium down onto the cementum may occur due to ageing or periodontal disease. Loss of attachment produces a periodontal pocket and a new habitat for anaerobic11 oral bacteria.
Epithelium - a layer of cells which forms alining for a tube or the covering for an organ or the whole body.
Eucaryote - a cell in which the genetic12 material is confined to the nucleus13, in distinction to a procaryote in which the genetic material is dispersed14 throughout the cell. Other distinctions of eucarytoic cells are the presence of organelles such as the golgi apparatus15, endoplasmic reticulum, lysosomes and mitochondria
Exocrine glands16 - the secretion17 passes intoa duct like sweat, saliva18 and mucous19.
Extinct - a plant or animal species may entirely20 cease to exist. Recent examples are the dodo, a large flightless bird which used to live as recently as two hundred years ago, on the island of Mauritius. There are today many species of birds, flowers, fish, insects, large mammals, including certain types of whale, which are threatened with extinction21, most as a result of human activity. Happily, the smallpox22 virus is about to become extinct
Extra cellular23 matrix - the supporting surrounding material of a cell including ground substance and fibres.
Extrinsic24 fibres - refers to those fibres of cementum which are continuous with periodontal ligament fibres. Extrinsic fibres have been trapped in cementum during its formation in order to anchor them. see also intrinsic fibres, and sharpey's fibres.
Exudate - the fluid plasma25 which leaks out of blood vessels26 due to an increase in capillary27 permeability. The increased permeability, is caused by histamine, and bradykinin, which are released in response to tissue damage. The formation of an exudate is the first step in the process of inflammation.
