2. Respiratory System and Measurement

Question 1

Respiration

Answer 1

exchange of O2 and CO2 (deliver O2, remove CO2) between main organs and lungs

Question 2

Diaphragm

Answer 2

main muscle involved in breathing

• when breath in, contracts, enlarges space, pulls air in
• when you breath out, expands, shrinks space, pushes air out

Question 3

Capillary / Aveoli exchange

Answer 3

Small blood vessels w thin walls, wrapping aveoli
aveoli (from lungs) - high O2, low CO2
capillaries (from body) - low O2, high CO2
exchange of gases

Question 4

Dead space

Answer 4

volume of air not available for gas exchange w blood

Question 5

Tidal Volume (TV)

Answer 5

Volume of gas inspired / expired during normal respiration

Question 6

Residual Volume (RV)

Answer 6

amount of gas remaining in lungs after max expiration

Question 7

Functional Residual Volume (FRV)

Answer 7

amount of gas remaining in lungs after normal expiration

Question 8

Vital Capacity (VC)

Answer 8

max amount of gas expelled from lungs after max inspiration

Question 9

Total Lung Capacity (TLC)

Answer 9

Amount of gas contained in lungs after max inspiration

Question 10

Spiro-meter

Answer 10

• measures LV under constant temperature & pressure
• volume inside changes with change in LV as patients breath
• can only measure TV, not gas remaining

Question 11

Nitrogen washout estimate of lung volume

Answer 11

• modified spirometer
• inhale pure O2, but exhale O2/Co2/N2, amount of N2 gradually decreases
• can measure RV and FRV

Question 12

Helium dilution estimate of lung volume

Answer 12

• modified spirometer, with added He
• patient breaths normally until [He] is in equilibrium w lungs and spirometer
• can measure lung volume

Question 13

Measurement of Oxygen Consumption

Answer 13

• spirometer with CO2 absorber

- when breath, exhaled CO2 combines with absorber and forms solid carbonate - can detect O2 consumption in lungs

Question 14

Measurement of oxygen saturation level

Answer 14

• measured through natural pigments in the body (e.g. melanin, hemoglobin)
• probe placed over vascular bed, LEDs emit 2 different wavelengths (red and infrared), photodetectors detect light signals in volts
• uses Beer Lambert Law to calculate

Question 15

Beer Lambert Law

Answer 15

Beer law - absorption of light related to [ ] of sample

Lambert law - absorption of light related to thickness of sample