A minimal amount of pleural fluid present in the pleural cavity:

1.	provides a medium for the exchange of respiratory gases
2.	reduces friction between the visceral and parietal pleurae
3.	provides lubrication for movements of the diaphragm
4.	permits the exchange of electrolytes during respiration

Oxygenated blood through the tissues of the lungs is carried by:
1. pulmonary and bronchial veins
2. pulmonary and bronchial arteries
3. pulmonary veins and bronchial arteries
4. pulmonary arteries and bronchial veins

Vagal stimulation would lead to:
1. deeper inhalation
2. forced exhalation
3. bronchodilation
4. bronchoconstriction

When the diaphragm or external intercostal muscles contract, intrapulmonary pressure should

When air leaks into the space between lung and chest wall, the result can be:
1. pneumothorax and atelectasis
2. hydrothorax and hemothorax
3. empyema and emphysema
4. pneumonitis and effusion

Air conditioning – warming, humidifying and filtering of the air, is the function performed by:

During deglutition, the food is prevented from entering into the larynx by the cartilaginous:

The trachea divides into two primary bronchi where the right with respect to the left is:
1. wider
2. longer
3. more horizontally oriented
4. all of the above

The diffusion of gases in lungs occur across the respiratory membrane. Which of the following is incorrect regarding the respiratory membrane?
1. it is the only barrier between the blood and the inhaled gases within each alveolus
2. basement membranes of alveolar type I cells and their adjacent capillaries are fused
3. oxygen cannot diffuse through the membrane and so must be actively transported
4. carbon dioxide diffuses across the membrane from the blood into the alveolar lumen

In normal resting respiration, the active and passive processes respectively are:
1. inhalation, exhalation
2. exhalation, inhalation
3. expiration, inspiration
4. eupnea, hyperpnea