| alveolar ventilation (VA) | the volume of gas that reaches the alveolar region of the lung.
|
 |
|
|
| alveoli | microscopic air sacs located in the lung where gas exchange occurs between respiratory gases and the blood.
|
|
|
|
| anatomical dead space | the total volume of the lung (i.e., conducting airways) that does not participate in gas exchange.
|
|
|
|
| aortic bodies | receptors located in the arch of the aorta that are capable of detecting changes in arterial PO2.
|
|
|
|
| Bohr effect | the right shift of the oxyhemoglobin dissociation curve due to a decrease of blood pH. Results in a decreased affinity for oxygen.
|
|
|
|
| bulk flow | mass movement of molecules from an area of high pressure to an area of lower pressure.
|
|
|
|
| carotid bodies | chemoreceptors located in the internal carotid artery; respond to changes in arterial PO2, PCO2, and pH.
|
|
|
|
| cellular respiration | process of oxygen consumption and carbon dioxide production in cells (i.e., bioenergetics).
|
|
|
|
| deoxyhemoglobin | hemoglobin not in combination with oxygen.
|
|
|
|
| diaphragm | the major respiratory muscle responsible for inspiration. Dome-shaped--separates the thoracic cavity from the abdominal cavity.
|
|
|
|
| diffusion | random movement of molecules from an area of high concentration to an area of low concentration.
|
|
|
|
| hemoglobin | a heme-containing protein in red blood cells that is responsible for transporting oxygen to tissues. Hemoglobin also serves as a weak buffer within red blood cells.
|
|
|
|
| myoglobin | protein in muscle that can bind oxygen and release it at low PO2 values; aids in diffusion of oxygen from capillary to mitochondria.
|
|
|
|
| oxyhemoglobin | hemoglobin combined with oxygen; 1.34 ml of oxygen can combine with 1 g Hb.
|
|
|
|
| partial pressure | the fractional part of the barometric pressure due to the presence of a single gas, e.g., PO2, PCO2, and PN2.
|
|
|
|
| pleura | a thin lining of cells that is attached to the inside of the chest wall and to the lung; the cells secrete a fluid that facilitates the movements of the lungs in the thoracic cavity.
|
|
|
|
| pulmonary respiration | term that refers to ventilation (breathing) of the lung.
|
|
|
|
| residual volume (RV) | volume of air in the lungs following a maximal expiration.
|
|
|
|
| respiration | external respiration is the exchange of oxygen and carbon dioxide between the lungs and the environment; internal respiration describes the use of oxygen by the cell (mitochondria).
|
|
|
|
| spirometry | measurement of various lung volumes.
|
|
|
|
| tidal volume | volume of air inhaled or exhaled in a single breath.
|
|
|
|
| total lung capacity (TLC) | the total volume of air the lung can contain; equal to the sum of the vital capacity and the residual volume.
|
|
|
|
| ventilation | the movement of air into or out of the lungs (e.g., pulmonary or alveolar ventilation); external respiration.
|
|
|
|
| ventilatory threshold (Tvent) | the "breakpoint'' at which pulmonary ventilation and carbon dioxide output begin to increase exponentially during an incremental exercise test.
|
|
|
|
| vital capacity (VC) | the volume of air that can be moved into or out of the lungs in one breath; equal to the sum of the inspiratory and expiratory reserve volumes and the tidal volume.
|