| frenulum of ileocaecal valve | A fold, more evident in cadavers, running from the junction of the two commissures of the ileocaecal valve on either side along the inner wall of the caecocolic junction. Synonym: frenulum valvae ileocaecalis, frenulum of Morgagni, Morgagni's frenum, Morgagni's retinaculum. (05 Mar 2000) |
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| left atrioventricular valve | <anatomy, cardiology> The heart valve that divides the left atrium and left ventricle. During left atrial contraction, the mitral valve opens to allow blood to flow into the left ventricle. Upon closure, the mitral valve prohibits the regurgitation of blood back into the left atrium. The mitral valve is the only heart valve that has only 2 valve cusps (all others have 3). (13 Nov 1997) |
| lunula of semilunar valve | The free border of a semilunar valve at each side of the nodulus valvulae semilunaris. Synonym: lunula valvulae semilunaris. (05 Mar 2000) |
| abdominal pressure | Pressure surrounding the bladder; estimated from rectal, gastric, or intraperitoneal pressure. (05 Mar 2000) |
| absolute pressure | Pressure measured with respect to zero pressure. Compare: gauge pressure. (05 Mar 2000) |
| acoustic pressure | In ultrasound, the instantaneous value of the total pressure minus the ambient pressure; unit is pascal (Pa). (05 Mar 2000) |
| air pressure | The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment. (12 Dec 1998) |
| atmospheric pressure | The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned. (12 Dec 1998) |
| back pressure | Pressure exerted upstream in the circulation as a result of obstruction to forward flow, as when congestion in the pulmonary circulation results from stenosis of the mitral valve or failure of the left ventricle. (05 Mar 2000) |
| back-pressure renal atrophy | <radiology> Caliectasis without obstruction, due to repeated episodes of obstruction, gradual loss of renal pyramids (12 Dec 1998) |
| barometric pressure | The absolute pressure of the ambient atmosphere, varying with weather, altitude, etc.; expressed in millibars (meteorology) or mm Hg or torr (respiratory physiology); at sea level, one atmosphere (atm, 760 mm Hg or torr) is equivalent to: 14.69595 lb/sq in, 1013.25 millibars, 1013.25 × 106 dynes/cm2, and, in SI units, 101,325 pascals (Pa). Synonym: atmospheric pressure. (05 Mar 2000) |
| bile duct pressure | <radiology> Normal: 15-20 cm H2O (12 Dec 1998) |
| biting pressure | Any force exerted upon the occlusal surfaces of teeth. Synonym: biting pressure. (05 Mar 2000) |
| blood pressure | <cardiology, physiology> The force that the circulating blood exerts on the walls of the arteries. This measurement is divided into systolic (pressure during contraction of the heart) and diastolic (pressure during relaxation phase). Blood pressure varies with age and sex of the individual. A rough rule of thumb for normal systolic pressure is 100 + Age of individual. In children 2 x (age) + 80 = systolic BP The diastolic pressure should be roughly 2/3 the systolic pressure. (27 Sep 1997) |
| blood pressure determination | Techniques for measuring blood pressure. (12 Dec 1998) |