PSL 431 Respiratory Physiology Part
3 (Exam 5) Questions and Answers
Rapid Shallow Breathing - ANSWER-Causes under ventilation of the alveoli; alveolar
hypoventilation - rapid shallow breathing is used to suppress hiccups, since this
causes CO2 to accumulate in the blood stream and suppress spasmic contractions
of the diaphragm - also occurs during exercise, but this is generally accompanied by
an increase in tidal volume as well as the frequency of breathing; increase in
breathing occurs in response to an increase in metabolic demand, it is called
hyperpnea rather than hyperventilation.
Deep Breathing - ANSWER-A better way to improve the overall efficiency of
breathing compared to increasing breathing frequency of breathing alone; increases
the respiratory fraction (Valv/Vt).
Alveolar Ventilation - ANSWER-Useful ventilation - generally assessed indirectly by
measuring arterial blood gas concentrations, rather than using spirometry to
measure tidal volume and making assumptions about anatomic dead space.
Alveolar Ventilation - ANSWER-Adjusted by changing the depth or frequency of
breathing to maintain alveolar partial pressure of oxygen slightly higher than 100 mm
Hg - changes also have important inverse effects on alveolar partial pressure of
CO2; regulating alveolar P CO2 and arterial P CO2 is critically important for
maintaining whole body acid-base balance.
Teeter Totter - ANSWER-Arterial partial pressure of CO2 is always on a ___ with
alveolar ventilation; an increase in breathing (increase in alveolar ventilation) serves
to blow off CO2 - an increase in arterial partial pressure of O2 (high alveolar
ventilation) causes a decrease in arterial partial pressure of CO2 (vice versa).
pH - ANSWER-Really small changes in CO2 have really big changes in ___; big %
change in the normal range.
Respiratory Quotient - ANSWER-The overall rate of O2 consumption and CO2
production is not quite the same; O2 uptake per minute = 250 ml/min; CO2 loss per
minute = 200 ml/min.
Atmospheric Partial Pressures - ANSWER-PO2 = 160; PCO2 = 0.3; PH2O =
variable.
Alveolar Gas Partial Pressures - ANSWER-PO2 = 105; PCO2 = 40; PH2O = 47.
Arterial Blood Partial Pressures - ANSWER-PO2 = 100; PCO2 = 40; PH2O = none.
3 (Exam 5) Questions and Answers
Rapid Shallow Breathing - ANSWER-Causes under ventilation of the alveoli; alveolar
hypoventilation - rapid shallow breathing is used to suppress hiccups, since this
causes CO2 to accumulate in the blood stream and suppress spasmic contractions
of the diaphragm - also occurs during exercise, but this is generally accompanied by
an increase in tidal volume as well as the frequency of breathing; increase in
breathing occurs in response to an increase in metabolic demand, it is called
hyperpnea rather than hyperventilation.
Deep Breathing - ANSWER-A better way to improve the overall efficiency of
breathing compared to increasing breathing frequency of breathing alone; increases
the respiratory fraction (Valv/Vt).
Alveolar Ventilation - ANSWER-Useful ventilation - generally assessed indirectly by
measuring arterial blood gas concentrations, rather than using spirometry to
measure tidal volume and making assumptions about anatomic dead space.
Alveolar Ventilation - ANSWER-Adjusted by changing the depth or frequency of
breathing to maintain alveolar partial pressure of oxygen slightly higher than 100 mm
Hg - changes also have important inverse effects on alveolar partial pressure of
CO2; regulating alveolar P CO2 and arterial P CO2 is critically important for
maintaining whole body acid-base balance.
Teeter Totter - ANSWER-Arterial partial pressure of CO2 is always on a ___ with
alveolar ventilation; an increase in breathing (increase in alveolar ventilation) serves
to blow off CO2 - an increase in arterial partial pressure of O2 (high alveolar
ventilation) causes a decrease in arterial partial pressure of CO2 (vice versa).
pH - ANSWER-Really small changes in CO2 have really big changes in ___; big %
change in the normal range.
Respiratory Quotient - ANSWER-The overall rate of O2 consumption and CO2
production is not quite the same; O2 uptake per minute = 250 ml/min; CO2 loss per
minute = 200 ml/min.
Atmospheric Partial Pressures - ANSWER-PO2 = 160; PCO2 = 0.3; PH2O =
variable.
Alveolar Gas Partial Pressures - ANSWER-PO2 = 105; PCO2 = 40; PH2O = 47.
Arterial Blood Partial Pressures - ANSWER-PO2 = 100; PCO2 = 40; PH2O = none.
