| Alveoli | Air sacs in the lungs |
| Bifurcation | Splitting into 2 branches |
| Bronchus | Bifurcation of the trachea; passageway into the air spaces of the lungs |
| Bronchioles | Smallest branches of the bronchi; lead to the alveoli |
| Capillary | Smallest blood vessel |
| Cilia | Thin hairs attached to the mucous membrane epithelium lining the respiratory tract |
| Carbon Dioxide (CO2) | Gas released by tissue cells and transported to the heart and lungs for exhalation |
| Diaphragm | Thin, muscular partition separating the thoracic and abdominal cavities |
| Epiglottis | Leaf-like pieces of cartilage over the trachea to prevent aspiration of food |
| Expiration | Breathing out; exhalation |
| External Respiration | Gas exchange occurring in the lungs |
| Glottis | Opening to the larynx |
| Inspiration | Breathing in; inhalation |
| Internal Respiration | Gas exchange occurring at the tissue level |
| Larynx | Voice box |
| Mediastinum | Space between the lungs |
| Mucous Membranes | Specialized form of epithelial tissue that secretes mucus |
| Mucus | Slimy substance produced by mucous membranes |
| Olfactory | Condition of smelling |
| Oxygen (O2) | Gas that enters the blood through the lungs and travels to the heart to be pumped to the rest of the body |
| Pharynx | Throat |
| Pleura | Membrane surrounding each lung |
| Pleural Cavity | Space between the pleural membranes and surrounding each lung |
| Respiration | Exchange of oxygen and carbon dioxide between the body and the atmosphere |
| Trachea | Windpipe |
| Agonal | Respirations near death |
| Antitussives | Substances used to control and prevent coughing |
| Asphyxia | Blockage of breathing leading to hypoxia; suffocation |
| Aspiration | Inhalation of a foreign substance into the respiratory tract |
| Asthma | Chronic inflammatory disorder marked by dyspnea and wheezing |
| Atelectasis | Incomplete dilation of a lung |
| Auscultation | Listening with a stethoscope to sounds within the body |
| Emphysema | Lung disease caused by enlargement of the alveoli |
| Epistaxis | Nosebleed |
| Hyperpnea | Increased depth of breathing |
| Hyperventilation | Abnormal, rapid, deep breathing |
| Hypopnea | Slow or shallow breathing |
| Instubation | Placement of a tube |
| Metastasis | To spread beyond control |
| Mucolytics | Substances used to break down or dissolves mucus |
| Palliative | Relieving symptoms, but not curing |
| Paroxysmal | Sudden occurrence such as a spasm or seizure |
| Percussion | Tapping a surface to determine the density of the underlying structure |
| Phlegm | Thick mucus excreted in large quantities |
| Pleural Effusion | Escape of fluid into the pleural cavity |
| Pneumonia | Acute inflammation and infection of the alveoli |
| Purulent | Containing pus |
| Rales and Crackles | Crackling noises heard on inspiration due to fluid in the alveoli |
| Rhonchi | wheezing; high pitched whistling sounds heard during inspiration |
| Sputum | Mucous secretion from the lungs, bronchi and trachea |
| Stridor | Strained shrill heard during inspiration due to an airway obstruction |
