Dictionary

catabolism See metabolism.

catalepsy A body’s persistence in unusual postures, with waxy rigidity of the limbs, mutism, and complete inactivity, regardless of outside stimuli, as is sometimes seen in catatonic schizophrenia.

catalyst A substance that speeds up a chemical reaction but is not consumed or altered in the process. Catalysts are of immense importance in chemistry and biology. All enzymes are catalysts that expedite the biochemical reactions necessary for life. The enzymes in saliva, for example, accelerate the conversion of starch to glucose, doing in minutes…

cataplexy A debilitating condition in which a person suddenly feels weak and collapses at times of strong emotion such as during laughter, anger, fear, or surprise. In so collapsing, people with cataplexy may injure themselves. For example, laughter and other emotions may trigger a reflex that can bring many of the muscles of the body…

cataract A clouding or loss of transparency of the lens in the eye as a result of increased water content. There are many causes of cataracts, including aging, cortisone medication, trauma, diabetes, and other diseases. Cataracts affect most people who live into old age. Symptoms include double or blurred vision and sensitivity to light and…

cardiology The study and treatment of heart disorders.

cardiomyopathy Disease of the heart muscle (myocardium).

cardiomyopathy, hypertrophic A heart defect characterized by increased thickness (hypertrophy) of the wall of the left ventricle, the largest of the four chambers of the heart.

cardioplegia Paralysis of the heart, as may be done electively in stopping the heart during cardiac surgery. Cardioplegia may be done using chemicals, cold (cryocardioplegia), or electrical stimulation.

cardiopulmonary Having to do with both the heart and lungs.

cardiopulmonary bypass Bypass of the heart and lungs (for example, during open-heart surgery). Blood returning to the heart is diverted through a heart-lung machine (a pump-oxygenator) before it is returned to the arterial circulation. The machine does the work of both the heart and the lungs, by pumping blood as well as supplying oxygen to…

cardiopulmonary resuscitation A life-saving emergency procedure that involves breathing for the victim and applying external chest compression to make the heart pump. Abbreviated CPR. In the early stages of a heart attack, death can often be avoided if a bystander starts CPR within 5 minutes of the onset of ventricular fibrillation. When paramedics arrive, medications…