 | Term | Definition |
| |
airway |
tube through which air flows between external enviroment and lung alveoli |
| |
alveolar dead space |
volume of fresh inspired air that reaches alveoli but does not undergo gas exchange with blood |
| |
alveolar pressure |
air pressure in pulmonary alveoli |
| |
alveolar ventilation |
volume of atmospheric air entering alveoli each minute |
| |
alveoli |
think walled, air filled "outpocketing" from terminal air passageways in lungs |
| |
anatomic dead space |
space in respiratory tract airways where gas exchange does no occur with blood |
| |
apneustic center |
area in the lower pons in the brain with input to the medullary inspiratory neurons; helps to terminate inspiration |
| |
atmospheric pressure |
air pressure surrounding the body |
| |
Boyle's Law |
pressure of a fixed amount of gas in a container is inversely proportional to container's volume |
| |
bronchi |
large-diameter air passage that enters lung; located between trachea and bronchioles |
| |
bronchiole |
small airway distal to bronchus |
| |
carbamino hemoglobin |
compound resulting from combination of carbon dioxide and amino groups in hemoglobin |
| |
carbamino anhydrase |
enzyme that catalyses the reaction of Carbon dioxide and water to H2CO3 |
| |
carotid body |
pertaining to two major artieris in neck that convey blood to head |
| |
central chemoreceptor |
receptor in brainstem medulla oblongata that responds to H+ concentration changes of brain extracellular fluid |
| |
conducting zone |
network of cardiac mucle fibers specialized to conduct electrical actity between differenet areas of heart |
| |
Dalton's law |
pressure exerted by each gas in a mixture of gases in independent of the pressure exerted by the other gases |
| |
deoxyhemoglobin |
hemoglobin not combined with oxygen; reduced hemoglobin |
| |
diaphragm |
dome-shaped skeletal muscle sheet that separates the adbominal and thoracic cavities; principal muscle of respiration |
| |
2,3-diphosphoglycerate |
substance produced by erthrocytes during glcolysis; binds reversibly to hemoglobin, causing it to release oxygen |
| |
elastic recoil |
tendency of an elastic structure to oppose stretching or distortion |
| |
expiration |
movement of air out of lungs |
| |
expiratory reserve volume |
volume of air that can be exhaled by mazimal contraction of expiratory muscles after normal resting expriation |
| |
functional residual capacity |
lung volume after relaxed expiration |
| |
globin |
collective term for the four polypepetide chains of the hemoglobin molecule |
| |
heme |
iron-containing organic molecul bond to each of the four polypeptide chains of hemoglobin or to cytochromes |
| |
hemoglobin |
protien composed of four polypepetide chians, each attached to a heme; loacatied in erthroctues and transports most blood oxygen |
| |
Henry's law |
amount of gas dissolved in a liquid is proportional to the partial presssure of gas with which the liquid is in equilibrium |
| |
Hering-breuer reflex |
inflation of the lung stimulates afferent nerves, which inhibt the inspiratory nerves in the medulla and thereby help to terminate inspiration |
| |
inspiration |
air movement from atmospher into lungs |
| |
inspiratory reserve volume |
maximal air volume that can be inspired above resting tidal volume |
| |
intercostal muscle |
skeletal muscle that lies between ribs and whose contraction causes rib cage movement during breathing |
| |
intrapleural fluid |
thin fluid film in thoracic cavity between pleura lining the inner wall of thoracic cage and pleura covering lungs |
| |
intrapleural pressure |
pressure in pleural space; also called intrathoracic pressure |
| |
iron |
metallic molecule comprising a portion of the heme structure of oxygen-binding proteins like hemoglobin and myoglobin |
| |
j receptor |
receptors in the lung capillary walls or interstitium that respond to increased lung intersitial pressure |
| |
larynx |
part of air passageway between pharynx and trachea; contains the vocal chords |
| |
lateral traction |
force holding small airways open; exerted by eleastic connective tissue linked to surrounding alveolar tissue |
| |
law of laplace |
transmural pressure difference=2x surgace tension divided by the radius of a hollow ball |
| |
lung compliance |
change in lung volume caused by a given change in transpulmonary pressure; the greater the lung compliance the mor stretchable the lung wall |
| |
mediastinum |
memebrane separating right and left thoracic comparments |
| |
medullary inspiratory neuron |
neurons in the medulla oblongata that set the pace for inspiration; their rate of firing is rhythmical but can be overridden by conscious control |
| |
minute ventilation |
total ventilation per minute; equals tidal volume times respiratory rate |
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