Exam 40: Physical Principles of Gas Exchange; Diffusion of Oxygen and Carbon Dioxide Through the Respiratory Membrane

A child has been eating M&Ms (plain) and inhaled one down his airway, blocking his left bronchiole. Which of the following will describe the changes that occur? Left Lung Alveolar Left Lung Alveolar Systemic Asterial A. \uparrow \uparrow \uparrow B. \uparrow \uparrow \leftrightarrow C. \uparrow \downarrow \downarrow D. \uparrow \leftrightarrow \uparrow E. \downarrow \downarrow \downarrow

If a lung having a normal ventilation-perfusion ratio $( = 1 )$ suddenly develops a ventilation/perfusion ratio of $< 1$ , which of the following will occur? A. A decrease in arterial $\mathrm { pO } _ { 2 }$ B. An increase in alveolar $\mathrm { pO } _ { 2 }$ C. A decrease in cardiac output D. A decrease in arterial $\mathrm { pCO } _ { 2 }$

If alveolar surface area is decreased 50% and pulmonary edema leads to a doubling of diffusion distance, how does diffusion of oxygen compare with normal?

A patient has a normal oxygen partial pressure and content in pulmonary venous blood but his systemic arterial blood shows a significantly lower than normal oxygen partial pressure and content. This is diagnostic of which of the following?

Blood gas measurements in a patient on room air indicates that his systemic arterial oxygen content is normal (19.5 ml O₂/100 ml blood), but his systemic venous oxygen content is low (6 ml O₂/100 ml blood). This is characteristic of which of the following?

Twin patients, $X$ and $Y$ , both have resp irations of 12 breaths/min, tidal volumes of 500 $\mathrm { mL }$ , and dead space of $100 \mathrm {~mL}$ . Patient $X$ 's resp iratory rate decreases by half and the tidal volume doubles. Patient Y's resp iratory rate doubles and the tidal volume decreases by half. After 2 minutes, what conditions would best describe their alveolar gases, as compared with normal? Patient X Alveolar Ventilation $\quad \underline { \text { Patient } \mathrm { Y } }$ Alveolar Ventilation Alveolar Alveolar Alveolar Alv eolar A. \uparrow ↓ \uparrow ↓ B. ↓ \uparrow ↓ ↓ C. \uparrow ↓ ↓ \uparrow D. \uparrow \uparrow \uparrow \uparrow E. \downarrow \uparrow \downarrow \uparrow

For a patient at sea level (barometric pressure = 760 mm Hg) and breathing 40%, oxygen calculate alveolar pO₂ is which of the following?

Values of $\mathrm { pO } _ { 2 } = 116 \mathrm {~mm} \mathrm { Hg }$ and $\mathrm { pCO } _ { 2 } = 27 \mathrm {~mm}$ Hg most closely describe which of the following? A. Atmospheric air B. Alveolar air C. Blood in the left heart D. Blood in the right heart E. Expired air

A human experiment is being performed where forearm blood flow is being measured under a variety of conditions. The forearm is warmed, resulting in an increase in blood flow. Which of the following occurs? A. Tissue interstitial $\mathrm { PO } _ { 2 } \mathrm { w }$ ill increase B. Tissue interstitial $\mathrm { PCO } _ { 2 }$ will increase C. Tissue $\mathrm { pH }$ will decrease

A person with normal lungs at sea level $( 760 \mathrm {~mm} \mathrm { Hg } )$ is breathing $50 \%$ oxygen. What is the approximate alveolar $\mathrm { pO } _ { 2 }$ ? A. 100 B. 159 C. 310 D. 330 E. 380

In an individual, the $\mathrm { pO } _ { 2 }$ and $\mathrm { pCO } _ { 2 }$ in different alveoli varies as follows: Alveolus A 100 40 Alveolus B 40 45 Alveolus C 150 0 Which of the following statements is true? A. Alveolus $\mathrm { B }$ is indicative of a dead space ventilation B. Alveolus $\mathrm { C }$ is indicative of pulmonary shunt C. Breathing $100 \% \mathrm { O } _ { 2 }$ would increase $\mathrm { PO } _ { 2 }$ in alveolus $\mathrm { C }$ D. Hyperventilation would increase $\mathrm { PO } _ { 2 }$ in alveolus $\mathrm { B }$