KEY WORD DEFINITIONS
Acid base balance: - the mechanisms the body uses to keep its fluid close to
neutral; pH (normal level of 7.35 – 7.45), neither basic nor acidic, so the body can
function normally. Lungs and Kidneys are integral in maintaining the normal acid
base balance.
Aldosterone: - a steroid hormone of the adrenal cortex that functions in the
regulation of salt and water balance of the body.
Angiotensin: - either of two forms of kinin of which one has vasoconstrictive
action. OR
a synthetic amide derivative of the physiologically active form used to treat some
form of hypotension.
Antidiuretic hormone (ADH): - also called vasopressin. A polypeptide hormone
secreted by the posterior lobe of the pituitary gland or obtained synthetically that
increases blood pressure and decreases urine flow.
Diffusion: - the state of being spread out or transmitted especially by contact, the
action of diffusing.
Edema: -an abnormal infiltration and excess accumulation of serous fluid in
connective tissue or in serous cavity (called dropsy)
Extracellular: - situated or occurring outside the cell or cells of the body.
Hypertonic: -exhibiting excessive tone or tension. OR
Having a higher osmotic pressure than a surrounding medium or a fluid under
comparison.
Hypotonic: - having a deficient tone or tension. OR
Having lower osmotic pressure than a surrounding medium or a fluid under
comparison.
Interstitial space: -fluid filled areas that surround the cells of a given tissue. Also
known as third space.
Intracellular: - within the cells.
Isotonic: - of equal tension. OR
Denoting a solution in which body cells can be bathed without net flow of water ac
ross the semipermeable cell membrane; also, denoting a solution having the same tonicity as anothe
r solution with which it is compared.
Natriuretic peptides: Any peptide that stimulates the kidneys to excrete salt and water.
Osmolarity: - normal is 270 to 300 mOsm/L. The concentration of a solution in
terms of osmoles of solutes per liter of solution.
pH: - the acidity or alkalinity of a solution, based on the amount of hydrogen ions
available
Renin: - enzyme produced by the kidney in conditions of abnormally low blood
pressure. An enzyme that converts angiotensinogen to angiotensin I.
Third space: - interstitial space