Oedemaexcessive accumulation of fluid in the tissues or body cavities; often results in swelling of the area |
Oestrogenfemale sex hormone secreted by the ovary |
Olfactionscientific name for the sensation of smell |
Oliguriareduced urine output |
Omnivoreanimal that eats both plants and meat |
Organa group of tissues that perform a particular function |
Organic substancea substance that is derived from a living organism or contains hydrocarbon groups, for example fats and carbohydrates |
Orthopnoeabreathing in an upright position, usually standing; the elbows are abducted to minimise compression of the chest wall |
Osmoregulationthe maintenance of optimal osmotic pressure by controlling water and salt content of body fluids |
Osmosisthe movement of water from an area of low concentration to one of high concentration through a semipermeable membrane, in order to equalise the concentrations on each side of the membrane |