PSL201Y1 Study Guide - Midterm Guide: Internal Intercostal Muscles, Obstructive Lung Disease, External Intercostal Muscles
Document Summary
Inspiration occurs as the external intercostal muscles and the diaphragm contract. During quiet expiration: the inspiratory muscles relax, causing the diaphragm to rise superiorly and the chest wall move inwards, the pressure in the lung rises, forcing air out of the lungs and airways. Expiration is usually a passive process, but during forced expiration (from exercise, blowing up a balloon, coughing or sneezing) the abdominal-wall muscles and the internal intercostal muscles can also contract during expiration to force additional air from the lungs. The fev1 (%) decreased proportionally as the radius decreased: explain why the results from the experiment suggest that there is an obstructive, rather than a restrictive, pulmonary problem. The fev1 (%) decreased proportionally as the radius decreased which is characteristic of an obstructive pulmonary problem. Spirometer: device the measures the volume of air inspired and expired by the lungs over a specified period of time (water-filled spirometer wet-lab)
