Chapter 15 Flashcards
Anatomic dead space
The volume of the conducting airways from the external environment down to the terminal bronchioles
Apneustic center
Group of neurons in the pons that has a stimulatory effect on the inspiration center
Atelectasis
An abnormal condition characterized by the collapse of lung tissue. It prevents respiratory exchange of O2 & carbon dioxide
Bohr effect
The property of hemoglobin by which an increasing concentration of protons &/or carbon dioxide reduces the O2 affinity for hemoglobin
Boyle’s law
A gas law that states pressure & volume are inversely related, assuming a constant temperature
Compliance
The ease in which lungs & thorax expand during pressure changes. The greater the compliance, the greater expansion
Dalton’s law
The total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of gases
Expiratory reserve volume
The amount of gas that can be forcefully exhaled after expiration of the normal tidal volume
External respiration
The transfer (diffusion) of O2 & carbon dioxide between the inspired air & pulmonary capillaries
Fick principle
The assumption that the amount of 02
Delivered to an organ is equal to the amount of 02 consumed by that organ plus the amount of 02 carried away from that organ
This principle is used to determine cardiac output
Henry’s law
A law stating that the constant temp, the amount of gas that dissolves in a liquid is directly proportional to the partial pressure of that gas in equilibrium w/ that liquid
Hering-Breuer reflex
A reflex in which afferent impulses from stretch receptors in the lungs arrest inspiration. Expiration then occurs. Inflation & deflation reflexes are triggered to prevent overinflation of the lungs
Hypoxemia
A lower than normal 02 content of the blood as measured in an arterial blood sample
Inadvertent hyperventilation
Excessive ventilation that is thought to result in increased intrathoracic pressure & decreased coronary perfusion pressure; aka rescuer hyperventilation
Inspiratory reserve volume
The maximum volume of air that can be inspired after inspiration of tidal volume
Intrapulmonic pressure
The pressure of the gas in alveoli
Intrathoraic pressure
The pressure in the pleural space; aka intrapleural pressure
Minute volume
The amount of gas inhaled or exhaled in 1 minute. It is found by multiplying the tidal volume by the respiratory rate
Pneumotaxic center
A group of neurons in the pons that have an inhibitory effects on the inspiratory center
Positive end-expiratory pressure (PEEP)
Airway support that maintains a degree of positive pressure at the end of exhalation
Pressure gradient
The force produced by differences between atmospheric pressure, intrapulmonic pressure, & intrathoracic pressure
Pressure support
A spontaneous mode of ventilation in which a ventilator delivers support w/ the preset pressure value for the pt’s own respiratory rate
Pulsus paradoxus
An abnormal decrease in systolic bp in which it drops more than 10 to 15mm Hg during inspiration compared w/ expiration
Residual volume
The volume of air remaining in the lungs after a max expiratory efforts
Torr
A non-systeme international unit of pressure defined as 1 standard atmosphere divide by 760, or about 1 mm Hg
Vallecula
A furrow between the glossoepiglottic folds on each side of the posterior oropharynx
Ventilation/perfusion mismatch
Any condition leading to interference of airflow at the alveolar level or blood flow at the pulmonary capillary level
