The long-standing model of pigment cell origins is implicitly based upon a progressive fate restriction model of neural crest development and postulates the existence of a partially restricted progenitor common to all pigment cell types (i.e., a chromatoblast) [38] .
Sodium is the fourth most abundant element on earth, comprising about 2.6% of the earth's crust; it is the most abundant of the alkali group of metals. It is now obtained commercially by the electrolysis of absolutely dry fused sodium chloride.
sodium. a chemical element, atomic number 11, atomic weight 22.990, symbol Na. (See Appendix 6.) Sodium is the major cation of the extracellular fluid, constituting 90 to 95 per cent of all cations in the blood plasma and interstitial fluid; it thus determines the osmolality of the extracellular fluid.The serum sodium concentration is normally about 140 mEq/L.odium lactate a compound used in solution to replenish body fluids and electrolytes. monobasic sodium phosphate. 1. a monosodium salt of phosphoric acid; used in buffer solutions, as a urinary acidifier, as a laxative, and as a source of phosphorus in hypophosphatemia, often in combination with potassium phosphate.