atmospheric pressure (redirected from Standard atmospheric pressure)

atmospheric pressure

[-fer′ik]

the pressure exerted by the weight of the atmosphere. The average atmospheric pressure at sea level is approximately 14.7 pounds per square inch. With increasing altitude the pressure decreases: at 30,000 feet, approximately the height of Mt. Everest, the air pressure is 4.3 pounds per square inch. Also called barometric pressure.

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atmospheric

of or pertaining to the atmosphere.

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atmospheric pressure

see atmospheric pressure.

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pressure

stress or strain, by compression, expansion, pull, thrust or shear.

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arterial pressure

the blood pressure in the arteries.

atmospheric pressure

the pressure exerted by the atmosphere, about 15 lb per square inch (2.17 kPa) at sea level.

capillary pressure

the blood pressure in the capillaries.

central venous pressure (CVP)

see central venous pressure.

cerebrospinal pressure

the pressure of the cerebrospinal fluid, normally 100 to 150 mmHg.

diastolic pressure

the lowest pressure recorded in the arterial blood pressure cycle. Represents the minimal pressure in the left ventricle which can maintain its ejection phase. See also blood pressure.

pressure gauge

a device attached to the outlet of gas tanks to measure internal pressure which indicates the quantity of gas remaining.

pressure gradient

the rate of increase (or decrease) in the magnitude of the pressure being measured.

intracranial pressure (ICP)

see intracranial pressure.

intraocular pressure (IOP)

the pressure exerted against the outer coats by the contents of the eyeball.

pressure load

see flowload.

mean circulatory filling pressure

a measure of the average (arterial and venous) pressure necessary to cause filling of the circulation with blood; it varies with blood volume and is directly proportional to the rate of venous return and thus to cardiac output.

pressure natriuresis

thought to participate in regulating the volume of extracellular fluid levels when the normal neurohumoral mediators are impaired; the increase in water and sodium ion excretions which occur when blood pressure is elevated because of an increase in the circulating blood volume.

pressure necrosis

necrosis of tissue caused by exclusion of circulation by external compression, e.g. in prolonged recumbency, or due to too-tight bandage, collar, harness.

negative pressure

pressure less than that of the atmosphere.

oncotic pressure

the osmotic pressure of a colloid in solution.

osmotic pressure

the potential pressure of a solution directly related to its solute osmolar concentration; it is the maximum pressure developed by osmosis in a solution separated from another by a semipermeable membrane, i.e. the pressure that will just prevent osmosis between two such solutions.

pressure point granuloma

see pressure points (below).

pressure point pyoderma

see pressure points (below).

pressure points

parts of the body subject to pressure when the animal is recumbent, wearing harness or saddlery, or during restraint. Usually bony prominences such as the point of the hock, hip, shoulder, elbow and lateral aspects of limbs. These are predisposed to callus formation, infection pyoderma and granulomas.

positive pressure

pressure greater than that of the atmosphere.

pulse pressure

difference between systolic and diastolic pressures in arteries.

pressure receptors

e.g. the blood pressure receptors in the aortic arch and the carotid sinus.

pressure sore

decubitus ulcer.

systolic pressure

the highest reading in the arterial blood pressure cycle. A reflection of the ejection pressure of left ventricular systole, and the elasticity of the arterial system.

venous pressure

the blood pressure in the veins. See also central venous pressure.

wedge pressure

intravascular pressure as measured by a swan-ganz catheter introduced into the pulmonary artery; it permits indirect measurement of the mean left atrial pressure.

pressure wrap

bandages which apply pressure to underlying tissues; used after trauma to limit the development of edema, and in the management of lymphedema.