Biomaterial Database

Are the small airways really quiet? 1982

K P van de Woestijne

The results of recent epidemiological studies and of functional-pathological correlations suggest that morphologic alterations, specifically inflammatory lesions, of the peripheral airways (with an interval diameter of 2 mm or less) influences the values of FEV1, of the FEV1/VC ratio and of the maximal midexpiratory flow rate, also in the incipient stages of these lesions. Between the so-called tests of small airways obstruction and FEV1 there would only be a difference in sensitivity. This implies that the small airways are not as silent as postulated previously. This is corroborated by measurements of resistance of peripheral airways performed on excised human lungs, showing that with normal lungs as well as in cases of airways obstruction, the peripheral resistance constitutes 50 to 90% of the total resistance between the main bronchus and the pleura.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008170	Lung Compliance	The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)	Compliance, Lung,Compliances, Lung,Lung Compliances
D008173	Lung Diseases, Obstructive	Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.	Obstructive Lung Diseases,Obstructive Pulmonary Diseases,Lung Disease, Obstructive,Obstructive Lung Disease,Obstructive Pulmonary Disease,Pulmonary Disease, Obstructive,Pulmonary Diseases, Obstructive
D008450	Maximal Midexpiratory Flow Rate	Measurement of rate of airflow over the middle half of a FORCED VITAL CAPACITY determination (from the 25 percent level to the 75 percent level). Common abbreviations are MMFR and FEF 25%-75%.	Forced Expiratory Flow 025-075 Percent,FEF 25-75 Percent,Flow Rate, Maximal Midexpiratory,MMFR,25-75 Percent, FEF,25-75 Percents, FEF,FEF 25 75 Percent,FEF 25-75 Percents,Forced Expiratory Flow 025 075 Percent,Percent, FEF 25-75,Percents, FEF 25-75
D001980	Bronchi	The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.	Primary Bronchi,Primary Bronchus,Secondary Bronchi,Secondary Bronchus,Tertiary Bronchi,Tertiary Bronchus,Bronchi, Primary,Bronchi, Secondary,Bronchi, Tertiary,Bronchus,Bronchus, Primary,Bronchus, Secondary,Bronchus, Tertiary
D005541	Forced Expiratory Volume	Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.	Forced Vital Capacity, Timed,Timed Vital Capacity,Vital Capacity, Timed,FEVt,Capacities, Timed Vital,Capacity, Timed Vital,Expiratory Volume, Forced,Expiratory Volumes, Forced,Forced Expiratory Volumes,Timed Vital Capacities,Vital Capacities, Timed,Volume, Forced Expiratory,Volumes, Forced Expiratory
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000403	Airway Resistance	Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.	Airway Resistances,Resistance, Airway,Resistances, Airway
D012907	Smoking	Willful or deliberate act of inhaling and exhaling SMOKE from burning substances or agents held by hand.	Smoking Behaviors,Smoking Habit,Behavior, Smoking,Behaviors, Smoking,Habit, Smoking,Habits, Smoking,Smoking Behavior,Smoking Habits
D014797	Vital Capacity	The volume of air that is exhaled by a maximal expiration following a maximal inspiration.	Forced Vital Capacity,Capacities, Forced Vital,Capacities, Vital,Capacity, Forced Vital,Capacity, Vital,Forced Vital Capacities,Vital Capacities,Vital Capacities, Forced,Vital Capacity, Forced