PHYL 1010Y Chapter Notes -Hypercalcaemia
27 Feb 2014
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Document Summary
Importance of regulating plasma calcium concentration: critical to so many physiological functions, ca2+ is an important signal molecule, ca2+ is part of the ic cement that holds cells together at tight junctions, ca2+ is a cofactor in the coagulation cascade, plasma ca2+ concentrations affect the excitability of neurons, ca2+ follows the principle of mass balance, total body ca2+ is all the ca2+ in the body, distributed among all 3 compartments, intake is the ca2+ ingested & absorbed in the small intestine, output is the ca2+ loss from the body, primarily occurring in the kidneys. Main effector sites for calcium homeostasis: total body ca2+ is distributed among 3 compartments of the body, half bound to plasma proteins/molecule, other half diffuses across membranes through open ca2+ channels, lowest concentration here, ec gradients favor movement of ca2+ into cytosol when ca2+ channels open, extracellular fluid.
