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This value is inversely related to the total cross-sectional area of the blood vessel and also differs per cross-section, because in normal condition the blood flow has laminar characteristics. For this reason, the blood flow velocity is the fastest in the middle of the vessel and slowest at the vessel wall.
An ejection fraction (EF) is the volumetric fraction (or portion of the total) of fluid (usually blood) ejected from a chamber (usually the heart) with each contraction (or heartbeat). It can refer to the cardiac atrium , [ 1 ] ventricle , [ 2 ] gall bladder, [ 3 ] or leg veins, [ 4 ] although if unspecified it usually refers to the left ...
In whole blood (g/cm 3) In plasma or serum (g/cm 3) Water: Solvent 0.81-0.86 0.93-0.95 Acetoacetate: Produced in liver 8-40 × 10 −7: 4-43 × 10 −7: Acetone: product of bodyfat breakdown 3-20 × 10 −6: Acetylcholine: Neurotransmitter of the parasympathetic nervous system: 6.6-8.2 × 10 −8: Adenosine triphosphate: Energy storage total 3. ...
Clinically, the unknown volume is the patient's blood volume, with the tracer having been injected into the patient's blood stream and tagged to the blood plasma. Once the tracer is injected a technician takes five blood samples which undergo microhematocrit centrifugation to extrapolate true blood volume at time 0. The concentration of the I ...
Cerebral blood flow (CBF) is the blood supply to the brain in a given period of time. [8] In an adult, CBF is typically 750 millilitres per minute or 15.8 ± 5.7% of the cardiac output . [ 9 ] This equates to an average perfusion of 50 to 54 millilitres of blood per 100 grams of brain tissue per minute.
The Fick principle states that blood flow to an organ can be calculated using a marker substance if the following information is known: Amount of marker substance taken up by the organ per unit time; Concentration of marker substance in arterial blood supplying the organ; Concentration of marker substance in venous blood leaving the organ
In a flow distribution network that progresses from a large tube to many small tubes (e.g. a blood vessel network), the frequency, density, and dynamic viscosity are (usually) the same throughout the network, but the tube radii change. Therefore, the Womersley number is large in large vessels and small in small vessels.
Free water clearance can be used as an indicator of how the body is regulating water. A free water clearance of zero means the kidney is producing urine isosmotic with respect to the plasma. Values greater than zero imply that the kidney is producing dilute urine through the excretion of solute-free water.