NURS 534 RESPIRATORY 2025/2026 QUESTIONS WITH
ANSWERS GRADED A+
✔✔Alveoli - ✔✔the primary gas exchange unit of the lungs
✔✔Pores of Kohn - ✔✔Holes in the alveolar walls that allow for collateral ventilation and
even distribution of air among alveoli
✔✔type 1 alveolar cells - ✔✔responsible for alveolar structure
✔✔type 2 alveolar cells - ✔✔responsible for surfactant production, which prevents lung
collapse; Surfactant reduces the surface tension, allowing the alveolus to enlarge (if no
surfactant is present, alveoli will collapse)
✔✔alveolar microphages - ✔✔cells within alveoli which ingest foreign material, and
remove it through the lymphatic system
✔✔Anatomic dead space - ✔✔The volume of gas in the conducting airways (not
contributing to gas exchange/respiration)
✔✔Tidal volume - ✔✔the volume of gas that enters the lungs during a normal
inspiration (letting breath in)
✔✔Vital capacity - ✔✔the volume of gas exhaled after maximum inspiration followed by
maximum expiration
✔✔Residual volume - ✔✔Amount of gas remaining in lungs after expiration (letting
breath out)
✔✔Functional residual capacity - ✔✔The volume of gas remaining in lungs after normal
inspiration/expiration
✔✔Spirometry - ✔✔a measurement of breathing (or lung volumes), can measure tidal
volume and vital capacity ***Total lung capacity, functional residual capacity and
residual volume CANNOT be measured with spirometry***
✔✔Total ventilation - ✔✔tidal volume X respiratory frequency (volume of air per minute
X ventilatory rate (breaths/min))
✔✔alveolar ventilation - ✔✔the amount of gas entering the alveoli (the amount of air
available for gas exchange; some air, usually about 150 mL, that is inhaled is "lost" or
"left behind" in the anatomic dead space of the conducting airways)
, ✔✔physiologic dead space - ✔✔the amount of the lungs that does not eliminate CO2
(usually minimal, but it increases, or worsens, with lung diseases)
✔✔acinus - ✔✔the portion of the lung distal to a terminal bronchial, it is is made up of
alveolar sacs; it is surrounded by pulmonary capillaries
✔✔alveocapillary membrane - ✔✔--Is formed by shared alveolar and capillary walls
--Structures include the thin membrane of alveolar epithelium, alveolar basement
membrane, interstitial space, capillary basement membrane, and capillary endothelium
(don't need to memorize these structures)
**Gas exchange occurs here**
✔✔simple diffusion - ✔✔movement from an area of higher pressure to an area of lower
pressure; the process by which O2 and CO2 move between air and blood
✔✔Fick's Law of Diffusion - ✔✔The amount of gas that moves across a sheet of tissue
is proportional to the area of the sheet but inversely proportional to its thickness; the
bigger surface area of the tissue, the more movement of gas across; the thicker the
tissue, the less amount of gas moving across
(do not need to memorize the actual equation)
--CO2 has higher MW and gas solubility than O2, which is the reason why ***CO2
diffuses more rapidly than O2***
✔✔blood gas barrier - ✔✔Small capillaries wrap around the enormous number of alveoli
creating an extensive diffusion area; **big surface area (between 50 and 100 m2) and
thin tissue mean lots of air moving across the blood gas barrier**
✔✔diffusion-limited gas exchange - ✔✔means that the gas will diffuse across the
pulmonary membrane as long as the partial pressure gradient is maintained; example:
exchange of CO (carbon monoxide) across a pulmonary capillary
✔✔perfusion-limited gas exchange - ✔✔means that the partial pressure gradient is not
maintained, so blood flow must be increased in order to increase the amount of gas
transported; Example: exchange of N2O (nitrous oxide) across a pulmonary capillary
✔✔What else affects the rate of diffusion? - ✔✔Can be changed by exercise (because it
reduces how much time blood spends in the capillary), and altered by alveolar hypoxia,
as well as thickening of the blood gas barrier
✔✔What is the diameter of a capillary and why? - ✔✔7 to 10 μm (it needs to be large
enough for red blood cells to pass through)
✔✔About how much time does blood spend in a capillary at rest? - ✔✔0.75 seconds
ANSWERS GRADED A+
✔✔Alveoli - ✔✔the primary gas exchange unit of the lungs
✔✔Pores of Kohn - ✔✔Holes in the alveolar walls that allow for collateral ventilation and
even distribution of air among alveoli
✔✔type 1 alveolar cells - ✔✔responsible for alveolar structure
✔✔type 2 alveolar cells - ✔✔responsible for surfactant production, which prevents lung
collapse; Surfactant reduces the surface tension, allowing the alveolus to enlarge (if no
surfactant is present, alveoli will collapse)
✔✔alveolar microphages - ✔✔cells within alveoli which ingest foreign material, and
remove it through the lymphatic system
✔✔Anatomic dead space - ✔✔The volume of gas in the conducting airways (not
contributing to gas exchange/respiration)
✔✔Tidal volume - ✔✔the volume of gas that enters the lungs during a normal
inspiration (letting breath in)
✔✔Vital capacity - ✔✔the volume of gas exhaled after maximum inspiration followed by
maximum expiration
✔✔Residual volume - ✔✔Amount of gas remaining in lungs after expiration (letting
breath out)
✔✔Functional residual capacity - ✔✔The volume of gas remaining in lungs after normal
inspiration/expiration
✔✔Spirometry - ✔✔a measurement of breathing (or lung volumes), can measure tidal
volume and vital capacity ***Total lung capacity, functional residual capacity and
residual volume CANNOT be measured with spirometry***
✔✔Total ventilation - ✔✔tidal volume X respiratory frequency (volume of air per minute
X ventilatory rate (breaths/min))
✔✔alveolar ventilation - ✔✔the amount of gas entering the alveoli (the amount of air
available for gas exchange; some air, usually about 150 mL, that is inhaled is "lost" or
"left behind" in the anatomic dead space of the conducting airways)
, ✔✔physiologic dead space - ✔✔the amount of the lungs that does not eliminate CO2
(usually minimal, but it increases, or worsens, with lung diseases)
✔✔acinus - ✔✔the portion of the lung distal to a terminal bronchial, it is is made up of
alveolar sacs; it is surrounded by pulmonary capillaries
✔✔alveocapillary membrane - ✔✔--Is formed by shared alveolar and capillary walls
--Structures include the thin membrane of alveolar epithelium, alveolar basement
membrane, interstitial space, capillary basement membrane, and capillary endothelium
(don't need to memorize these structures)
**Gas exchange occurs here**
✔✔simple diffusion - ✔✔movement from an area of higher pressure to an area of lower
pressure; the process by which O2 and CO2 move between air and blood
✔✔Fick's Law of Diffusion - ✔✔The amount of gas that moves across a sheet of tissue
is proportional to the area of the sheet but inversely proportional to its thickness; the
bigger surface area of the tissue, the more movement of gas across; the thicker the
tissue, the less amount of gas moving across
(do not need to memorize the actual equation)
--CO2 has higher MW and gas solubility than O2, which is the reason why ***CO2
diffuses more rapidly than O2***
✔✔blood gas barrier - ✔✔Small capillaries wrap around the enormous number of alveoli
creating an extensive diffusion area; **big surface area (between 50 and 100 m2) and
thin tissue mean lots of air moving across the blood gas barrier**
✔✔diffusion-limited gas exchange - ✔✔means that the gas will diffuse across the
pulmonary membrane as long as the partial pressure gradient is maintained; example:
exchange of CO (carbon monoxide) across a pulmonary capillary
✔✔perfusion-limited gas exchange - ✔✔means that the partial pressure gradient is not
maintained, so blood flow must be increased in order to increase the amount of gas
transported; Example: exchange of N2O (nitrous oxide) across a pulmonary capillary
✔✔What else affects the rate of diffusion? - ✔✔Can be changed by exercise (because it
reduces how much time blood spends in the capillary), and altered by alveolar hypoxia,
as well as thickening of the blood gas barrier
✔✔What is the diameter of a capillary and why? - ✔✔7 to 10 μm (it needs to be large
enough for red blood cells to pass through)
✔✔About how much time does blood spend in a capillary at rest? - ✔✔0.75 seconds
