Hyponatremia feedback loop is overwhelmed by increased fluid intake, 2) the feedback loop malfunctions such that ADH is always "turned on"; 3) the receptors in the kidney are always "open" regardless of there being no signal from ADH to be open; or 4) there is an increased ADH even though there is no normal stimulus (elevated serum sodium) for ADH to be increased. Hyponatremia occurs in one of two ways: either the osmoreceptor-aquaporin feedback loop is "overwhelmed", or it is "interrupted". If it is interrupted, it is either "related" or "not related" to ADH. If the feedback system is overwhelmed, this
Serum iron Serum iron Serum iron is a medical laboratory test that measures the amount of circulating iron that is bound to transferrin (90%) and serum ferritin (10%). Clinicians order this laboratory test when they are concerned about iron deficiency, which can cause anemia and other problems. 65% of the iron in the body is bound up in hemoglobin molecules in red blood cells. About 4% is bound up in myoglobin molecules. Around 30% of the iron in the body is stored as ferritin or hemosiderin in the spleen, the bone marrow and the liver. Small amounts of iron can be found