971. Which of the following statement is TRUE?
A. Surfactant acts to keep alveoli dry.
B. Base of lung has small resting volume & expands well on inspiration.
C. Medium sized bronchi is the chief site of airway resistance
D. Intrapleural pressures reduces during inspiration
E. All of the above.
972. Which of the following statements is TRUE?
A. Central chemoreceptor respond directly to changes in blood pH.
B. Peripheral chemoreceptor is 100% responsible for ventilatory response to hypoxia
C. Central chemoreceptor is responsible for 80% of ventilatory response to hypercarbia.
D. Aortic bodies do not respond to acidosis
E. All of the above
973. Which of the following statement is true?
A. Hering Breuer inflation reflex respond to lung distension by slowing frequency of respiration.
B. Irritant receptors respond to noxious gases by reflex bronchoconstriction
C. J receptors respond to pulmonary capillary congestion by rapid shallow breathing
D. All of the above
E. None of the above
974. The total lung capacity consists of:
A. Vital capacity & tidal volume
B. Residual volume & vital capacity
C. Functional residual capacity & vital capacity
D. Tidal volume & functional residual capacity
E. Tidal volume & residual volume
975. The transfer of gas across the pulmonary capillary membrane is NOT:
A. diffusion limited for nitrous oxide
B. perfusion limited for carbon monoxide
C. said to be diffusion limited if it is dependent on blood flow
D. perfusion limited for oxygen under normal conditions
E. occurs in less than 0.2 seconds for oxygen in normal circumstances
976. Ventilation & perfusion relationships vary in the upright lung:
A. ventilation is greater at apex than base
B. perfusion is greater at apex than base
C. variation in ventilation is greater than perfusion
D. V/Q is more than 3x greater at apex than base
E. V IQ approaches unity at apex
977. Carbon dioxide is:
A. carried mostly as carbamino compounds in the blood
B. carried more effectively by oxygen saturated Hb
C. converted to bicarbonate primarily by plasma carbonic anhydrase in the periphery
D. carried by blood according to a much steeper dissociation curve than oxygen
E. mostly carried as bicarbonate in the blood, but the arteriovenous difference is mostly due to carbamino compounds.
978. The alveolar ventilation in a normal adult at rest would be:
A. 7500 ml
C. 4500 ml
D. 6150 ml
E. 5250 ml
979. Pulmonary vascular resistance
A. is greater in the lung during maximal inspiration rather than expiration
B. is about 111 0 that of systemic circulation
C. is decreased by recruitment by increased by distension
D. will decrease in poorly ventilated areas
E. is not affected by sympathetic nervous system
980. Regarding ventilation:
A. The most important muscles of ventilation are the intercostals
B. The internal intercostal muscle assist in inspiration
C. Compliance decreases with increasing volume
D. Compliance decreases with emphysema
E. The apex of the lung is better ventilated than the base but has a smaller volume of ventilation