effusion, pleural Excess fluid between the two membranes that cover the lungs (the visceral and parietal pleurae) separating the lungs from the chest wall. A small quantity of fluid is normally spread thinly over the visceral and parietal pleurae and acts as a lubricant between the two membranes. Any significant increase in the quantity of…
effusion, pericardial Too much fluid within the fibrous sac (pericardium) that surrounds the heart. The inner surface of the pericardium is lined by a layer of flat cells (mesothelial cells) that normally secrete a small amount of fluid, which acts as a lubricant to allow normal heart movement within the chest. A pericardial effusion involves…
effusion Too much fluid, an outpouring of fluid. For example, a pleural effusion is an abnormal accumulation of fluid in the pleural space between the lungs and the chest wall, while a knee effusion is an abnormal amount of fluid in the knee joint. A hemorrhagic effusion contains blood in the fluid.
efferent vessel A vessel that carries blood away from the heart. Hence, an efferent vessel is an artery or an arteriole (a little artery).
efferent nerve A nerve that carries impulses away from the central nervous system.
efferent Carrying away. For example, an artery is an efferent vessel that carries blood away from the heart, and an efferent nerve carries impulses away from the central nervous system. The opposite of efferent is afferent.
effect, founder See founder effect.
effacement Thinning of the cervix, which occurs before and while the cervix dilates.
EFA Essential fatty acid.
EEG Electroencephalogram.
Edwards syndrome See trisomy 18 syndrome.
edentulous Being without teeth. Complete loss of all natural teeth can substantially reduce quality of life, self-image, and daily functioning.