Chapter 13 Respiration
Revised 13 November 2008
What are the major functions of the respiratory system?
What is the difference between an alveolus and an airway?
What is the difference between conducting airways (zone) and the respiratory airways (zone)?
What are the functions of the conducting airways?
Where is the “mucus escalator” and what is its function? How does smoke affect this phenomenon?
What types of cells constitute the walls of an alveolus?
What are the two pleura membranes and where is each located? What lies between them?
What is the function of the pleura?
How is Boyle’s law relevant to inspiration?
What causes a pneumothorax? Which direction does the lung move? The chest wall?
What is meant by saying that a tidal inspiration is “active?” Which structures are involved?
What is meant by saying that resting expiration is “passive?” What are the forces responsible for a tidal expiration?
What is the composition and purpose of surfactant? From which cells in surfactant released?
How is surfactant involved in respiratory distress syndrome of the newborn?
According to the law of Laplace, what would happen to smaller alveoli if surfactant were not present?
How does the presence of surfactant affect the effort (intensity of muscle contraction) of inspiration?
What effect does lateral traction have on inspiration? Expiration?
Does Poiseulle’s law apply to conducting airways?
What is the effect of epinephrine and norepinephrine on the smooth muscles of conducting airways?
What is asthma? What are the symptoms? What can trigger an asthma attack?
What are the physiological explanations of the treatments for asthma?
What are the symptoms of chronic obstructive pulmonary disease (COPD)?
What is altered in the lungs of a person with emphysema?
What is the difference between a lung volume and a lung capacity?
What instrument is used to measure lung volumes and capacities?
What are the approximate normal values for tidal volume, respiratory rate, residual volume, vital capacity, and total lung capacity?
How is the FEV 1.0 test useful in detecting COPD?
What is the equation for minute ventilation?
What is the equation for alveolar minute ventilation? What would alveolar minute ventilation be if tidal volume was 150 ml in a normal person?
Which portions of the airways constitute anatomical dead space and what is the typical value for dead space in a normal person?
What is the other type of deadspace, that together with anatomic deadspace constitutes physiologic deadspace?
What is the respiratory quotient? If the diet was solely fats, what would RQ be? If protein only? If carbohydrate only? If the diet was balanced, mixed diet?
Use Dalton’s law of partial pressure to determine what the partial pressure of oxygen would be in air at sea level.
What is the most abundant gas in the atmosphere and why is it ignored in respiratory equations?
Why is it customary to refer to dissolved gases by partial pressure and not concentration? Which gas law relates the partial pressure of gases in liquids?
What determines arterial P CO2 and P O2 ?
What are the normal alveolar pressures for CO2 andO2 ?
What are the normal arterial pressures for CO2 andO2 ?
How would increasing ventilation affect alveolar P CO2 and P O2 ?
How could one raise alveolar P CO2 to a value greater than normal?
What is the difference between hyperventilation and hypoventilation? Why are these terms not based on oxygen?
What is meant by “ventilation-perfusion inequality?” How does this explain that arterial P O2 is not the same as alveolar P O2 ?
How does low O2 affect the radius of pulmonary arterioles? Of systemic arterioles?
In what two forms is oxygen transported in the blood? Which is the more abundant form?
Does oxygen bound to hemoglobin exert a partial pressure?
Reconstruct the oxyhemoglobin dissociation curve from memory, and know the % saturation at 40, 60, and 100 mmHg P O2 .
What is the significance of the “steep” portion of the oxygen-hemoglobin dissociation curve?
What is the significance of the “flat” portion of the oxygen-hemoglobin dissociation curve?
To what percentage is Hb saturated once it has passed through systemic capillaries? What is the significance of this degree of saturation?
How does carbon monoxide affect the oxyhemoglobin dissociation curve? What is the most practical treatment for a person with carbon monoxide poisoning? What is the theory underlying this treatment?
What else can hemoglobin bind? How does the binding of these substances affect the affinity of Hb for oxygen?
What factors cause the oxyhemoglobin dissociation curve to shift and in which direction? What does a “downward” shift mean physiologically? What does a “right” shift mean physiologically?
Which factors shift the curve to the right? How does this affect the loading and unloading of oxygen on hemoglobin?
In what three forms is carbon dioxide transported in the blood? What are the percentages for each form?
What is the location and purpose of the chloride shift?
How does cessation of ventilation (holding one’s breath) affect alveolar P O2 ? alveolar P CO2 ? Would this result in respiratory acidosis or alkalosis? How would the kidneys compensate?
How does hyperventilation affect alveolar P O2 ? alveolar P CO2 ? Would this result in respiratory acidosis or alkalosis? How would the kidneys compensate?
How does ventilation change in a person who is experiencing ketoacidosis? How do the kidneys and lungs compensate for this form of metabolic acidosis?
What is the origin of the rhythm for ventilation?
Diagram the negative feedback loop for the homeostatic regulation of blood pH, O2 and CO2? Where are the sensors, integrator, efferent pathway, and effectors?
What is the difference between peripheral and central chemoreceptors?
Why is the negative feedback system relatively unaffected by decreases in arterial O2 unlessthe levels fall below 60mmHg?
Why is the feedback system much more sensitive to small changes in CO2 ?
How and why does ventilation change in response to “rebreathing” the same air (e.g. the air inside a spirometer bell)?
What is the definition of hypoxia?
Why do persons with emphysema have difficulty exhaling? What techniques can such a person adopt to ease exhalation?
What is the explanation for hyperventilation that occurs at high altitude?
What accounts for the increase in minute alveolar ventilation during exercise? Can the changes be accounted for strictly by negative feedback?