Nutrition and Metabolism Essay Example | Topics and Well Written Essays - 1500 words

Nutrition and Metabolism - Essay Example the plasma sodium concentration), is about 140 mmol/L. Sodium maintains the osmotic pressure of the extra cellular fluid and helps in retaining water in the extra cellular compartment. Along with other cations it is also majorly involved in neuromuscular irritability, acid base balance, maintenance of blood viscosity and resting membrane potential. A high plasma sodium concentration (more than 145 mmol/L) is referred to as hypernatremia. This can occur due to simple dehydration, excess sodium intake, steroid therapy and diabetic insipidus. Hyponatremia (plasma sodium concentration less than 130 mmol/L), can occur due to diuretic medication, kidney disease, excessive sweating, congestive heart failure or gastrointestinal disorder. Potassium is one of the most important intracellular cation. It is widely distributed in the body in muscle tissue, nerve tissue, blood cells and plasma. It is filtered in the glomerulus, absorbed in the proximal tubule and finally excreted by exchange for sodium in the distal tubule. Potassium influences muscular activity, cardiac function and nerve conduction process. In hyperkalemia the plasma potassium concentration exceeds 5.5 mmol/L. Acute hyperkalemia is a medical emergency. In hypokalemia the plasma potassium level will be less than 3.5 mmol/L. This can occur due to excessive loss in gastrointestinal secretions and urine, and also in renal tubular acidosis. Hyponatremia (lowered plasma [Na+]) and hypernatremia (raised plasma [Na+]) are associated with a variety of diseases and illnesses and the accurate measurement of [Na+] in body fluids is an important diagnostic aid. Potassium is the major intracellular cation. The average cell has 140 mM K+ inside but only about 10 mM Na+. K+ slowly diffuses out of cells so a membrane pump (the Na+/K+-ATPase) continually transports K+ into cells against a concentration gradient. The human body requires about 50-150 mmol/day. Hypokalemia (lowered