Gas Exchange Flashcards
(34 cards)
Causes dilution of gasses in the upper resp
Humidification
Partial pressures of inspired air
Total 760 N2: 601 O2: 159 CO2 0.3 H20: variable
Occurs if humidification of air does not occur
Lung tissue damage or infection
Pp of H20 in alveoli
47 mm Hg
Pp flow of 02
o 159 mm inspired o 105 alveoli o 100 arterial o 40 systemic tissue o 40 veins
Pp flow of CO2
o 0.3 mm Inspired o 40 alveoli o 40 artery o 45 systemic tissue o 45 veins
Increased contact area with RBCs in alveolar capillaries
Thin walls
Layers of the resp membrane
- Fluid + surfactant
- Alveolar epithelium
- Basement membrane of epithelium
- Thin interstitial space
- Basement membrane of capillary
Capillary endothelium
Factors influencing diffusion across resp membrane
- Thickness (edema, fibrosis)
- Surface area
- Diffusion constant (co2 more rapid than 02)
- Pressure difference
Where oxygen is in transport
- 98.5% hemoglobin
- 1.5% dissolved in blood
Where oxygen binds
To the heme (fe) group on hemoglobin, up to 4. Now oxyhemoglobin
02 sat in arteries compared to veins
100% art, 80% vein
The oxy chart shift to the right means….
More 02 removal
the oxy chart shift to the left means
Less 02 removal
Causes more 02 removal
- Decrease in pH
- Increase in temp
- Increase in CO2
As it gets colder, oxygen is ________ to remove
harder
Methods of CO2 transport
- Bicarbonate (70%)
- Hemoglobin (23%)
- Blood (7%)
Acidosis effect of nervous system
Depression of CNS
Alkalosis effect of nervous system
Increased excitability of PNS
Chemical buffer systems
- Bicarbonate
- Phosphate
- Protein
Line of Buffers
- Chemical
- Resp
- Renal
More CO2 causes ______ bicarbonate
More, but also releases a acid
Phosphate buffer
More for intra/extracellular fluid than for blood
Protein buffers
- Includes hemoglobin
- Carboxyl group gets rid of H+
- Amino group accepts H+
- These side chains are present on 27 amino acids
