Respiratory Physiology Practice Questions

Alveolar surfactant is a substance produced by the lungs that helps to reduce surface tension within the alveoli. By reducing surface tension, alveolar surfactant prevents the collapse of the alveoli during expiration, allowing for easier and more efficient lung expansion and contraction. This ultimately increases pulmonary compliance, which refers to the ability of the lungs to stretch and expand. Therefore, the correct answer is compliance.

During forced (maximum) expiration, the contraction of the abdominal muscles is important. This contraction helps to increase the pressure in the thoracic cavity, which in turn helps to push air out of the lungs more forcefully. This is necessary during activities such as coughing, sneezing, or exercising when a larger volume of air needs to be expelled from the lungs quickly. In normal (quiet) expiration, the abdominal muscles are not actively contracted. Therefore, the correct answer is forced (maximum) expiration.

The patient has a restrictive disease because the measured values for vital capacity, residual volume, total lung capacity, and FEV-1 are all significantly lower than the predicted values. In a restrictive disease, the lungs are unable to fully expand, resulting in reduced lung volumes and capacities. This is supported by the low measured values for vital capacity, residual volume, and total lung capacity. The FEV-1/FVC ratio being greater than 80% indicates that there is no significant airflow obstruction, further supporting the diagnosis of a restrictive disease.

When a person breaks a rib, it can lead to a condition called pneumothorax, where air accumulates in the space between the lung and the chest wall. This can cause the affected lung to collapse partially or completely. As a result, the chest cavity may expand to accommodate the extra air, causing the circumference of the chest to be larger than normal.

normal value for a Man is 1.2 and woman is 1.1

Spirometry is a pulmonary function test that measures the amount and speed of air that can be inhaled and exhaled. FVC (Forced Vital Capacity) is one of the parameters measured during spirometry. It represents the maximum amount of air a person can forcefully exhale after taking a deep breath. FVC is an important measurement as it provides information about lung function and can help diagnose and monitor respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and restrictive lung diseases.

Con(orig) - Con(final) / Con(final) X Vol(bag) = .25/.55 X 2.5= 1.137

The correct answer is "descent of the floor of the diaphragm." In patients with emphysema, the lungs become hyperinflated due to the destruction of the alveolar walls. This hyperinflation causes the diaphragm to flatten and descend, resulting in an elongated mediastinum on chest X-rays. Elastase breaking down the covering of the mediastinum is not a known cause of an elongated mediastinum, and cardiac failure is not typically associated with this finding.

FEV1 stands for Forced Expiratory Volume in 1 second, which is a measure of the maximum amount of air a person can forcefully exhale in one second. In emphysema, the air sacs in the lungs become damaged, causing them to lose their elasticity. This leads to a decrease in lung function and a reduction in the ability to exhale air effectively. Therefore, it is expected that FEV1 would be below normal in emphysema.

premature baby, less surfactant, therefore, more surface tension, therefore smaller alveoli and therefore smaller RV

FEV1/FRC would be less than .8 in obstructive. Obstructive would have Increase in RV
interpleaural pressure is normal, in restrictive it would be changed (more negative) as the lung tried to recoil away from it

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