Flashcards in Chapter 42 - Guyton Deck (16):
Methods to assess pulmonary performance.
blood Po2, CO2, pH
Maximum expiratory flow
When a person expires with great force, the expiratory airflow reaches a maximum flow beyond which the flow cannot be increased any more even
with greatly increased additional force.
Forced expiratory vital capacity (FVC)
maximum inspiration followed by maximum expiration into a spirometer used as a clinical pulmonary test
Causes of pulmonary emphysema.
chronic infection, chronic obstruction, entrapment of air in the alveoli causing destruction
Effects of pulmonary emphysema.
increases airway resistance, decreased diffusing capacity in alveolar walls due to destruction, abnormal ventilation-perfusion ratios (physiologic shunt in some parts and physiologic dead space in others), pulmonary hypertension (right sided heart failure)
Any inflammatory condition of the lung in which some or all of the alveoli are filled with fluid and blood cells.
Collapse of the alveoli.
Atelectasis (caused by total obstruction of the airway or lack of surfactant in the fluids lining the alveoli)
With one lung entirely collapsed, mean oxygen saturation is not greatly affected (versus in pneumonia when it may be greatly reduced if only 1 lung is affected), why?
the collapsed lung does not receive much blood flow so all the blood must pass through the remaining lung, in pneumonia the mean oxygen saturation will be an average of the unaffected and affected lung so it will be greatly reduced
When the asthmatic person breathes in pollen to which he or she is sensitive (that is, to which the person has developed IgE antibodies), the pollen reacts with the mast cell–attached antibodies and causes the mast cells to release?
histamine, leukotrienes, eosinophilic chemotactic factor, bradykinin
The functional residual capacity and residual volume of the lung become especially ________ during the acute asthmatic attack because of the difficulty in expiring air from the lungs.
Tuberculosis is marked by decreased what?
vital capacity and breathing capacity; total respiratory membrane surface area; pulmonary diffusing capacity; and abnormal ventilation-perfusion ratio
Oxygen therapy is 100% effective in which type of hypoxia?
atmospheric (also can be effective for hypoventilation hypoxia but does nothing for increased CO2 caused by hypoventilation; also impaired alveolar membrane diffusion by increasing oxygen pressure gradient)
In which types of hypoxia is oxygen therapy not effective?
anemia, abnormal hemoglobin transport of oxygen, circulatory deficiency, or physiologic shunt, inadequate tissue use of oxygen
Excess carbon dioxide in the body fluids.
Hypercapnia usually occurs in association with hypoxia only when the hypoxia is caused by _____________ or __________ ____________.
hypoventilation; circulatory deficiency