Respiratory System - Advanced PDF Past Paper

Respiratory system - advanced 1. Hyperventilation (very rapid, deep breathing) may cause unconsciousness because a) Blood pCO2 is reduced so much that brain hypoxia occurs before an involuntary respiratory command is issued b) Blood pO2 is reduced so much that brain hypoxia occurs before an invol...

Respiratory system - advanced 1. Hyperventilation (very rapid, deep breathing) may cause unconsciousness because a) Blood pCO2 is reduced so much that brain hypoxia occurs before an involuntary respiratory command is issued b) Blood pO2 is reduced so much that brain hypoxia occurs before an involuntary respiratory command is issued c) Air does not remain in the lungs long enough to allow oxygen to be absorbed d) Blood pCO2 increases so much that hypercapnia occurs 2. Which is the main mechanism regulating breathing and respiratory distress? a) Chemoreceptors monitoring pCO2 b) Chemoreceptors monitoring pO2 c) Baroreceptors monitoring air pressure d) Chemoreceptors monitoring the concentraion of heamoglobin in the blood 3. In acidosis (blood pH below normal), haemoglobin: a) Releases less oxygen at a given pO2 b) Releases more oxygen at a given pO2 c) Is unaffected at a given pO2 d) Binds more CO2 at a given pO2 4. When body temperature rises above normal (37 deg C), haemoglobin: a) Binds more CO2 at a given pO2 b) Is unaffected at a given pO2 c) Releases less oxygen at a given pO2 d) Releases more oxygen at a given pO2 5. What is the significance of the oxygen-haemoglobin saturation curve? a) It is irrelevant as pO2 is always constant b) It expresses the relationship between pCO2 and level of haemoglobin saturation c) It expresses the relationship between pO2 and the level of haemoglobin saturation d) It expresses the relationship between pO2 and tissue oxygen consumption 6. The binding and dissociation of oxygen to haemoglobion is a typical reversible reaction. At equilibrium: a) Oxygen molecules bind to haeme at the same rate that other oxygen molecules are being released b) Oxygen molecules are bound to all available haeme groups c) No oxygen molecules are bound to haeme d) Oxygen bind to haeme at the same rate as CO2 molecules 7. What is the effect of rebreathing expired air? a) Increased pCO2 causes increased rate and decreased depth of breathing b) Decreased pCO2 causes increased rate and decreased depth of breathing c) Increased pCO2 causes decreased rate and increased depth of breathing d) Increased pO2 causes decreased rate and increased depth of breathing 8. Why is it possible to resuscitate a non-breathing casualty with expired air? a) Because expired air is supplemented with atmospheric oxygen during resuscitation b) Because resuscitation allows the removal of CO2 from the blood c) Because air expired during normal breathing still contains sufficient oxygen to saturate haemoglobin d) Because resuscitation only needs to inflate the lungs 9. How does surfactant improve lung compliance? a) By reducing the intrapleural pressure. b) By reducing friction in the airways. c) By reducing the rigidity of lung tissue. d) By reducing the surface tension of the fluid lining the alveoli. 10. Neonatal respiratory distress syndrome is severely reduced lung compliance due to insufficient surfactant production which may occur in premature infants. It may be treated by: a) Delivering air under pressure to assist breathing b) Administering surfactant from other sources to the lungs c) Delivering oxygen to the lungs via a fluid d) All of the above 11. Which of the following structures produces speech? a) Pharynx b) Larynx c) Trachea d) Bronchi 12. Emphysema (degeneration of lung tissue) is characterised by reduced elastic recoil in the lungs. How would this affect breathing? a) Obstruction of airways b) Difficulty breathing in c) Difficulty breathing out d) Faster breathing movements 13. Kussmaul, deep, rapid respiration as seen in uncontrolled diabetes, will: a) Increase blood pH b) Decrease blood pH c) Increase blood volume d) Decrease blood volume 14. Carbonmonoxide combines irreversibly with haemoglobin to form carboxyhaemoglobin. This will cause: a) Reduced heart rate b) Severe tissue hypercapnia c) Severe tissue hypoxia d) Severe acidosis 15. What happens to the pressure in a gas as the volume of the container increases? a) Increases b) Decreases c) Remains the same d) Gases are incompressible, so the volume of the container cannot change 16. What lung volume cannot be measured with a spirometer? a) Vital capacity b) Inspiratory reserve c) Tidal d) Residual 17. Total oxygen consumption over time can be used to calculate: a) Body fat content b) Basal metabolic rate c) Cardiac output d) Blood sugar level 18. A significant factor in maintaining the normal pH of body fluids is the loss of which gas during external respiration? a) Oxygen b) Nitrogen c) CO2 d) Hydrogen 19. An increase in altitude causes a decrease in gas exchange efficiency because: a) less blood circulates through the lungs b) there is a decrease in oxygen pressure, therefore less of a gradient into the lungs during inspiration c) there are fewer red blood cells in the blood at high altitudes d) the surface area of the alveoli decrease 20. Dalton's Law describes: a) the principles of expansion b) the laws of partial pressures of gases c) the laws of temperature difference between partial gases d) the principles of temperature differences under water