| milk ejection | Reflex in which tactile stimulation of nipples causes release of oxytocin which causes myoepithelial cells surrounding mammary alveoli to contract and expel the milk. Applies to humans and animals. (12 Dec 1998) |
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| milk-ejection reflex | Release of milk from the breast following tactile stimulation of the nipple; the afferent path is postulated to exist from the nipple to the hypothalamus; the efferent limb is represented by the neurohypophysial release of oxytocin into the systemic circulation; contraction of myoepithelial elements within the breast, caused by oxytocin, moves milk into the collecting ducts and toward the nipple. Synonym: let-down reflex, milk let-down reflex. (05 Mar 2000) |
| ejection | 1. The act of ejecting or casting out; discharge; expulsion; evacuation. "Vast ejection of ashes." . "The ejection of a word." 2. <physiology> The act or process of discharging anything from the body, particularly the excretions. 3. The state of being ejected or cast out; dispossession; banishment. Origin: L. Ejectio: cf. F. Ejection. Source: Websters Dictionary (01 Mar 1998) |
| ejection fraction | <cardiology> A measure of ventricular contractility, equal to normally 65 |
| ejection murmur | A diamond-shaped systolic murmur produced by the ejection of blood into the aorta or pulmonary artery and ending by the time of the second heart sound component produced, respectively, by closing of the aortic or pulmonic valve. (05 Mar 2000) |
| ejection period | The period in the cardiac cycle when the semilunar valves are open and blood is being ejected from the ventricles into the arterial system. Synonym: ejection period. (05 Mar 2000) |
| ejection sounds | Click-like sounds during ejection from a hypertensive aorta or pulmonary artery or associated with stenosis (particularly congenital) of the aortic or pulmonic valve. (05 Mar 2000) |
| left ventricular ejection time | The time measured clinically from onset to incisural notch of the carotid or other pulse; properly the time of ejection of blood from the left ventricle beginning with aortic valve opening and ending with aortic valve closure. (05 Mar 2000) |
| accelerated phase of leukaemia | Refers to chronic myelogenous leukaemia that is progressing. The number of immature, abnormal white blood cells in the bone marrow and blood is higher than in the chronic phase, but not as high as in the blast phase. (12 Dec 1998) |
| acceleration phase | <cell biology, cell culture> A period of increasing growth before the log phase in a culture of microbes. After the culture is started on a medium, at first there is no growth (the lag phase) and then the microbes start to gradually grow (acceleration phase) until they reach a constant maximum rate of growth (log phase). (15 Jan 1998) |
| acute-phase protein | <haematology> These plasma proteins (in addition to fibrinogen) increase 25% or more in response to inflammation and injury are under direct control of interleukin-6 (IL-6) (hepatocyte-stimulating factor). Other proteins which increase are ceruloplasmin, C3 and C4 which increase 50% or more; alpha-1 acid glycoprotein, alpha-1 antitrypsin, haptoglobin and fibrinogen (the major determinant of viscosity 1 ) which increase two- to fourfold; C-reactive protein (CRP) and serum amyloid A which increase several hundred-fold. Despite long-held clinical opinion to the contrary, available data indicate that neither ESR nor measurement of specific acute-phase reactants are useful in excluding underlying infection or inflammation regardless of the pretest probability. These proteins are secreted into the blood in increased or decreased quantities by hepatocytes in response to trauma, inflammation, or disease. They can serve as inhibitors or mediators of the inflammatory processes. Certain acute-phase proteins have been used to diagnose and follow the course of diseases or as tumour markers. See also: amyloid, c-reactive protein, erythrocyte sedimentation rate, viscosity. (25 Jun 1999) |
| acute-phase reaction | <immunology, rheumatology> Refers to the changes in synthesis of certain proteins within the serum during an inflammatory response, which provides rapid protection for the host against microorganisms via non-specific defense mechanisms. It consists of fever, an increase in inflammatory humoral factors, and an increased synthesis by hepatocytes of a number of proteins or glycoproteins usually found in the plasma; the reaction is mediated by endogenous pyrogens, the hypothalamus, adrenal hormones, and other factors. (12 Jul 2000) |
| anal phase | In psychoanalytic personality theory, the stage of psychosexual development, occurring when a child is between 1 and 3 years, during which activities, interests, and concerns are centreed around the anal zone. (05 Mar 2000) |
| aqueous phase | The water portion of a system consisting of two liquid phase's, one mainly water, the other a liquid immiscible with water (e.g., benzene, ether). (05 Mar 2000) |
| blast phase | Refers to advanced chronic myelogenous leukaemia. In this phase, the number of immature, abnormal white blood cells in the bone marrow and blood is extremely high. Also called blast crisis. (12 Dec 1998) |