http://nsr.bioeng.washington.edu/model/ 2010-03-12T03:08:23-08:00 http://nsr.bioeng.washington.edu/model/ http://nsr.bioeng.washington.edu/model/lib/images/favicon.ico text/html 2010-01-21T15:47:40-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Red_cell_carriage:model_index&rev=1264117660&do=diff Back to Introduction The erythrocyte membrane potentially limits the exchange of solutes between erythrocytes (red blodd cells) and plasma water. The multiple indicator dilution technique can be used to investigate the effect of this barrier on the exchange of tracer substances. text/html 2010-01-21T15:26:44-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Two-barrier_model:model_index&rev=1264116404&do=diff Back to Introduction If a tracer is transformed within the cells, or if its distribution is heterogeneous, two intracellular regions have to be considered, with a second barrier between them. Lactate Lactate is a natural substrate of the liver. It is taken up by hepatocytes and is transformed to pyruvate by the action of the enzyme lactate dehydrogenase. The hydrogen atom bound to the central carbon atom of the molecule is transferred to NAD that is thus transformed to NADH. Various other d… text/html 2010-01-21T14:48:42-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Linear_flow_coupling:model_index&rev=1264114122&do=diff Back to Introduction To model the movement of substances through an organ, the movement along a single path of blood flow through the microcirculation is considered first. Each flow path consists of two portions: a capillary-bed portion, where exchange with extravascular space occurs, and a noncapillary-bed portion consisting of arteries, arterioles, venules, and veins where all indicators are confined to the vasculature. In linear systems, the order of serial connection is irrelevant, such … text/html 2010-01-21T14:25:00-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Simple_elimination:model_index&rev=1264112700&do=diff Back to Introduction A tracer that is rapidly equilibrated between the vascular an extravascular space and is eliminated from this space will exhibit flow-limited behavior with elimination. Sulfobromophthalein Sulfobromophthalein (BSP) is an organic dye used a for liver diagnostic. Its chemical structure is illustrated by the following formula: text/html 2010-01-05T14:09:38-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Tutorials:Lung&rev=1262729378&do=diff Mechanics OneAlvLung One Alveolus Lung Lung_RC Lung modeled analogously as electrical RC circuit Lung_RC_Air Lung with Concentration and non-linear compliance 2CompLung_Air Two compartment lung with concentrations and nonlinear compliances Lutchen This model is based on Lutchen et al. A nonlinear model combining pulmonary mechanics and gas concentration dynamics. IEEE Trans. Biomed. Eng. 29: 629-641, 1982.BronchiBronchiolAlvThis model represents airway with a bronchi,a bronchioles, and a alv… text/html 2009-12-08T15:26:07-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Flow_limited_model:model_index&rev=1260314767&do=diff Back to Introduction Rapid transport of a solute between the vascular and the extravascular space in a whole organ. Theory The liver sinusoids are lined by fenestrated endothelial cells. [sinusoid] The fenestrae are openings in the endothelial cells with a diameter of about 100 nm, much smaller than the diameter of an erythrocyte (ca. 7 µm). Therefore, erythrocytes do not cross the endothelium, they move along the sinusoids with the velocity of blood: text/html 2009-12-07T14:32:24-08:00 Bart jardine http://nsr.bioeng.washington.edu/model/doku.php?id=Transport_Physiology:Whole_organ_models:Goresky:Barrier_limited_model:model_index&rev=1260225144&do=diff Back to Introduction Theory Single capillary The concentrations in plasma, C1 and in tissue, C2, follow the following system of two differential equations in time, t, and space, x: [Eq. 1] where W is the linear velocity of the tracer the sinusoidal plasma, k1 and k2 are transfer coefficients or rate constants, defining the transfer of tracer between the plasma and tissue, and k3 is the transfer coefficient of sequestration of tracer due to metabolism and/or biliary excretion. text/html 2009-10-09T09:05:58-08:00 melanie http://nsr.bioeng.washington.edu/model/doku.php?id=wiki:dokuwiki&rev=1255104358&do=diff [Array] DokuWiki is a standards compliant, simple to use wp>Wiki, mainly aimed at creating documentation of any kind. It is targeted at developer teams, workgroups and small companies. It has a simple but powerful syntax which makes sure the datafiles remain readable outside the Wiki and eases the creation of structured texts. All data is stored in plain text files -- no database is required.