Capillaries: The smallest blood vessels in the body. A network of capillaries in tissues connects arterioles that bring blood to the tissues with venules
that return blood to the heart.
Cell: The smallest unit of a living structure capable of independent existence, composed of a membrane-enclosed mass of protoplasm and containing a
nucleus or nucleoid.
Chest: The anterior wall of the thorax, the upper part of the body between the neck and the abdomen.
Chest Cavity: Space in body surrounding the lungs.
Chyle: A milky fluid consisting of lymph and droplets of
triglyceride fat that becomes mixed with the blood.
Chronic: Referring to a health-related state, lasting a long time.
Chronic Bronchitis: A respiratory disease characterized chronic coughing that lasts for more than three months per year on successive years. It may be
accompanied by changes in structure of the airways of the lungs, inflammation, and enlargement of the mucous glands.
Chronic Obstructive Pulmonary Disease: A general term used for lung diseases with permanent or temporary narrowing of small bronchi, in which forced expiratory flow is slowed. It is
frequently used when no etiologic or other more specific term can be applied.
Cilia: Motile extensions of the surface of some airway epithelial cells that look like short thick hairs and act as filters in the nose and upper airway,
using a wave-like motion.
Colitis: Inflammation of the colon that can be associated with diarrhea, abdominal pain, bloating, and blood in the stool
Collagen: A group of rigid, fibrous proteins that serve as the main components of connective tissues of the body. Collagen is usually found in the
interstitium between cells.
Computed Tomography (CT) Scan: A test in which x-rays are used to create a picture of the body (i.e., a chest CT scan of the lungs), using a
computer-controlled machine (CT scanner).
Congenital: Existing at birth.
Cor Pulmonale (right-sided heart failure): A disease of the heart characterized by enlargement of the right ventricle. It is caused by increased resistance
to blood flow through the lung and can occur in severe lung disease and lead to heart failure.
Corticosteroid: A class of steroid-type drugs that are used to suppress inflammation and function as slow-acting bronchodilators. Examples include
prednisone, cortisone, fluticasone, beclomethasone, and others. Steroids are similar to hormones produced in the body's adrenal glands that serve as
Crackle: An ambiguous term used by doctors to describe an abnormal sound heard when listening for breath sounds during examination of the chest. It is used
by some to denote rhonchus and by others to denote crepitation. It is a synonym for the term "rale".
Crepitation: A specific term used by doctors to describe an abnormal sound heard when listening for breath sounds during examination of the chest. It
denotes a fine bubbling sound that resembles the noise heard on rubbing hair between the fingers.
Cyanosis: A bluish color of skin, fingernails, and mucous
membranes that indicates low level of oxygen in the blood.
Cystic Fibrosis: A inherited disease caused by mutations of the CFTR gene that affects the excretory glands, lungs, pancreas and other organs. In the
lungs, cystic fibrosis associated with the presence of thick mucus, bacterial colonization of the airways and repeated bouts of acute exacerbations of the lung disease.