Category: O

Oxidizing agents or electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (oxidation-reduction). In vivo, it appears that phagocyte-generated oxidants function as tumor promoters or cocarcinogens rather than as complete carcinogens perhaps because of the high levels of endogenous antioxidant defenses. It is also thought that oxidative damage in…

A female germ cell extruded from the ovary at ovulation. The egg cell produced by a female, one of over a million in each of the two ovaries at birth. Normally, only one ovum is fully matured and released each month, in the process called ovulation. If a sperm (male sex cell) unites with the…

Pertaining to or of the nature of osmosis (= the passage of pure solvent from a solution of lesser to one of greater solute concentration when the two solutions are separated by a membrane which selectively prevents the passage of solute molecules, but is permeable to the solvent).  

Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane. The passage of water through a semipermeable membrane, from a region of low concentration of solutes to one of higher concentration. Reverse osmosis is the passage of water from a more concentrated to a less…

The standard unit of osmotic pressure. A unit of osmotic pressure equal to the molecular weight of a solute in grams divided by the number of ions or other particles into which it dissociates in solution. The standard unit of osmotic pressure based on a one molal concentration of an ion in a solution.  

The concentration of osmotically active particles expressed in terms of osmoles of solute per litre of solution. Concentration of dissolved substance per liter of solution (such as plasma). Compare to osmolality, the concentration of dissolved substances per kilogram of solvent (often water). Osmolarity is affected by the volume of the various solutes in the solution…

An amino acid produced in the urea cycle by the splitting off of urea from arginine. An amino acid that occurs as a metabolic intermediate in the synthesis of urea, but not involved in protein synthesis, so of no nutritional importance. An amino acid produced by the liver. Ornithine is a nonessential amino acid synthesized…

Transference of an organ between individuals of the same species or between individuals of different species. A surgical operation to transplant an organ from one person to another.  

A male hospital attendant. A person who does general work in a hospital. A hospital attendant, without professional qualifications, who does heavy or routine work, such as transporting patients. An attendant in a hospital who does general work to assist nurses. Orderlies are responsible for lifting and transporting patients and preparing them for surgery (e.g.,…

The optimal state of the mouth and normal functioning of the organs of the mouth without evidence of disease.