Alveolus - air sac where gas exchange takes place.
Angina - chest pain.
Aorta - blood vessel that delivers oxygen-rich blood from the left ventricle to the body; it is the largest blood vessel in the body.
Apex - top portion of the upper lobes of the lungs.
Atrium - one of the two receiving chambers of the heart.
Base - bottom portion of lower lobes, located just above the diaphragm.
Blood pressure - pressure of blood against the walls of a blood vessel or heart chamber.
Bronchiolitis - inflammation that involves the bronchioles (small airways).
Bronchoscopy - the examination of the bronchi (the main airways of the lungs) using a flexible tube (bronchoscope). Bronchoscopy helps to evaluate and diagnose lung problems, assess blockages, obtain samples of tissue and/or fluid, and/or to help remove a foreign body.
Bronchus - large airways; lung divides into right and left bronchi.
Cardiac output - total amount of blood being pumped by the heart over a particular period of time.
Catheter - thin, flexible medical tube; one use is to insert it into a blood vessel to measure blood pressure.
Constrict - tighten; narrow.
Cyanosis - bluish color in the skin because of insufficient oxygen.
Diaphragm - primary muscle used for respiration, located just below the lung bases.
Diastolic pressure - lowest pressure to which blood pressure falls between contractions of the ventricles.
Dilate - relax; expand.
Dyspnea - sensation of difficulty in breathing.
Edema - swelling due to the buildup of fluid.
Endothelial cells - the delicate lining, only one cell thick, of the organs of circulation.
Expiration - exhaling; giving off carbon dioxide.
Fibrosis - process by which inflamed tissue becomes scarred.
Heartbeat - one complete contraction of the heart.
Hyperactive - describes a situation in which a body tissue is especially likely to have an exaggerated reaction to a particular situation.
Hypertension - abnormally high blood pressure.
Hypotension - abnormally low blood pressure.
Inspiration - inhaling; taking in oxygen.
Lobectomy - removal of an entire lobe of the lung.
Lung volume - the amount of air the lungs hold.
Mean blood pressure - average blood pressure, taking account of the rise and fall that occurs with each heartbeat. It is often estimated by multiplying the diastolic pressure by two, adding the systolic pressure, and then dividing this sum by three.
Palpitation - sensation of rapid heartbeats.
Perfusion - flow.
Pleura - membrane that covers the outside of the lung.
Pneumonectomy - removal of an entire lung.
Pulmonary artery - blood vessel delivering oxygen-poor blood from the right ventricle to the lungs.
Pulmonary hypertension - abnormally high blood pressure in the arteries of the lungs.
Respiration - gas exchange from air to the blood and from the blood to the body cells.
Smooth muscle - muscle that performs automatic tasks, such as constricting blood vessels.
Spirogram - record of the amounts of air being moved in and out of the lungs.
Syncope - fainting; temporary loss of consciousness.
Systemic - relating to a process that affects the body generally; in this instance, the way in which blood is supplied through the aorta to all body organs except the lungs.
Systolic pressure - the highest pressure to which blood pressure rises with the contraction of the ventricles.
Vasodilator - agent that widens blood vessels.
Ventilation - movement of air (gases) in and out of the lungs.
Ventricle - one of the two pumping chambers of the heart; right ventricle receives oxygen-poor blood from the right atrium and pumps it to the lungs through the pulmonary artery; left ventricle receives oxygen-rich blood from the left atrium and pumps it to the body through the aorta.