| Term | Definition |
| bronchitis | an inflammation of the tubes that carry air to and from the lungs |
| emphysema | chronic lung disease in which the alveoli are damaged. A loss of elasticity prevents alveoli from expanding |
| asthma | narrowing of the bronchi and bronchioles due to the constriction of muscles around the airways |
| cystic fibrosis | recessive, autosomal genetic disease in which lungs collect mucous and cause multiple infections. |
| yawning | a reflex consisting of the simultaneous inhalation of air and the stretching of the eardrums, followed by an exhalation of breath. Ventilates all alveoli. Possibly functions to cool the brain. |
| hiccups | a reflex consisting of the simultaneous inhalation of air and the stretching of the eardrums, followed by an exhalation of breath |
| coughing | a common reflex action that clears the throat of mucus or foreign irritants. The glottis closes and forces air superiorly from longs against glottis. It opens suddenly and blasts air outward. |
| sneezing | a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. Similar to a cough. Depressed uvula routes air upward through nasal cavity. |
| laughing/crying | Inspiration followed by releasing air in a number of short expirations, primarily emotionally induced |
| apex | superior tip of the lungs |
| base | inferior, flat base of the lungs against which the diaphragm sits. |
| lobes | Fissures divide the lungs into lobes. The right lung has 3 lobes while the left has two. |
| bronchiole | a small thin walled branch of a bronchus. They don't have cartilage rings and do have a muscular layer for contraction |
| bronchodilation | expansion of the bronchial airways |
| bronchoconstriction | contraction of the smooth muscle to reduce the airways in the lungs |
| primary bronchi | The branches of the airway that enter the lungs. |
| bronchial tree | the intricate system of air passages inside each lung. Air enters the lungs from two bronchi. |
| trachea | a cartilaginous tube that connects the pharynx and larynx to the lungs, allowing the passage of air. Also called the windpipe. |
| larynx | the hollow muscular and cartilaginous organ forming an air passage to the lungs and holding the vocal cords in humans and other mammals; the voice box. It sits on top of the trachea |
| glottis | the opening of the larynx that contains the vocal folds. |
| epiglottis | a flap made of elastic cartilage covered with a mucous membrane, attached to the entrance of the larynx. It covers the glottis while swallowing. |
| vocal folds | also known commonly as vocal cords or voice reeds, are two sets of tissue stretched across the larynx that can vibrate creating sound. |
| Boyle's law | the principle that the volume of a confined gas at constant temperature varies inversely with its pressure |
| cellular respiration | the set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into ATP and waste products (water and CO2) |
| diaphragm | the primary muscle used in the process of inspiration, or inhalation. It is a dome-shaped sheet of muscle that is inserted into the lower ribs under the lungs. |
| Functions of the respiratory system | gas exchange, conduction of air, defense against microorganisms, warm/humidify and cleanse air, maintaining homeostasis, vocalization |
| functions of the larynx | vocalization, keep airway open, direct food to the esophagus |
| voice production | Produced by vocal fold vibration. Longer, thicker cords produce lower tones (males). |
| respiratory epithelium | The ciliated cells and goblet (mucus) cells that line and protect the respiratory tract. They create a "mucus escalator" trapping debris and moving it upwards and out. |
| nares | nostrils |
| Paranasal sinuses | a group of four paired air-filled spaces that surround the nasal cavity. |
| conchae | also called a turbinate or turbinal, is a long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose creating air turbulence to warm, clean and humidify the air. |
| respiratory zone | the site of O2 and CO2 exchange with the blood. The respiratory bronchioles and the alveolar ducts are responsible for 10% of the gas exchange. The alveoli are responsible for the other 90%. |
| conducting zone | is made up of the nose, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles; their function is to filter, warm, and moisten air and conduct it into the lungs |
| pharynx | the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus and larynx |
| pulmonary ventilation | exchanges gases between the outside air and the alveoli of the lungs. (aka breathing). It depends on a difference between the atmospheric air pressure and the pressure in the alveoli. |
| internal respiration | an exchange of gases between the cells of the body and the blood |
| external respiration | the exchange of gases between the alveoli and the blood |
| inspiration | the process of drawing in breath (inhaling) |
| expiration | the process of expelling breath (exhaling) |
| alveoli | any of the many tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place. |
