Solutes and Horomones

erythropoietin

a hormone released by the kidneys in response to low oxygen levels in the blood; triggers the production of RBC's

renin

a hormone secreted by the juxtaglomerular complex in response to low blood pressure

angiotensin

once activated, a hormone that regulates blood pressure by increasing sodium reabsorption and constricting blood vessels

ADH

a hormone secreted by the pituitary gland that works to reabsorb water from the collecting duct

aldosterone

a hormone secreted by the adrenal glands that increases reabsorption of sodium ions, leading to water reabsorption

sodium

most important solute for regulating water balance

choloride

high levels are called hyperchloremia

calcium

release is triggered by PTH when levels of this ion are low

sodium

low levels is called hyponatremia

sodium

the most abundant solute in the ECF

potassium

low levels is called hypokalemia

calcium

ons are necessary for the contractions of heart and skeletal muscle and for the maintenance of strong bones

sodium

high levels leads to dehydration of CNS cells and increased neuromuscular twitching

bicarbonate buffer system

most important to maintain the pH of ECF

protein buffer system

carboxyl groups of amino acid polymers release free hydrogen ions in the presence of a high pH

bicarbonate buffer system

maintained by the supply of carbon dioxide provided by respiration

phosphate buffer system

important buffer system for ICF; utilizes a weak acid and a weak base to maintain pH

bicarbonate buffer system

carbonic acid supplies excess hydrogen ions when the pH is too high