Dictionary

respiratory papillomatosis, recurrent See laryngeal papillomatosis.

respiratory rate The number of breaths per minute or, more formally, the number of movements indicative of inspiration and expiration per unit time. In practice, the respiratory rate is usually determined by counting the number of times the chest rises or falls per minute. The aim of measuring respiratory rate is to determine whether the…

respiratory syncytial virus A virus that causes mild respiratory infections, colds, and coughs in adults and can produce severe respiratory problems, including bronchitis and pneumonia, in young children and anyone with compromised immune, cardiac, or pulmonary systems. Abbreviated RSV. RSV is spread via respiratory secretions and is highly contagious. Infections usually occur during annual community…

respiratory system The organs that are involved in breathing, including the nose, throat, larynx, trachea, bronchi, and lungs. Also known as the respiratory tree.

respiratory therapy Exercises and treatments that help patients recover lung function, such as after surgery.

resting phase See interphase.

restless leg syndrome An uncomfortable (creeping, crawling, tingling, pulling, twitching, tearing, aching, throbbing, prickling, or grabbing) sensation in the calves that occurs while sitting or while lying down. The result is an uncontrollable urge to relieve the uncomfortable sensation by moving the legs. Restless leg syndrome is a common cause of painful legs. The leg…

reticulocyte An immature red blood cell.

reticulocyte count The number of reticulocytes (young red blood cells) circulating in blood, usually less than 1 percent of the total number of red blood cells. Elevation of the reticulocyte count above 1 percent (reticulocytosis) is a sign of rapid red blood cell production.

retina The nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain. A small area called the macula in the retina contains special light-sensitive cells that allow clear perception and central vision. The retina is filled with tiny blood vessels. See also…

retinal detachment A separation of the retina from its connection at the back of the eye. The separation usually results from a tear (that is, a rent or rip, not a tear drop) in the retina, which often occurs when the vitreous gel pulls loose or separates from its attachment to the retina. Once the…

renal pelvis The area at the center of the kidney. Urine collects in the renal pelvis and is funneled into the ureter.