Control of Breathing Flashcards
(14 cards)
What are (4) airway characteristics?
- Rich blood supply
- Large surface area
- Tissues have intrinsic elastic properties
- Fluid lubrication (ensure rapid diffusion + counteract physical forces like surface tension)
How does high levels of CO2 affect the body?
changes the body’s pH = toxic
What are (3) factors affecting gas solubility?
- Partial pressure of gas
- Partial pressure of gas in liquid phase
- Solubility of a gas
What (3) key factors will influence gaseous exchange?
- Gas partial pressure and gas solubility
- Matching of alveolar ventilation with pulmonary blood perfusion
- Structural characteristics of the respiratory membrane
Where (in a healthy adult) is self-ventilating lung ventilation optimal?
lower 1/3 of lung (dependent region)
Which regions of the lung have a greater initial volume?
non-dependent (upper) lung
Which regions of the lung are partially expanded?
dependent (lower) lung
Why are the dependent (lower) lung regions partially expanded?
so they still have the capacity of further expansion + volume change
How much O2 is reversible bound or released is determined by what?
- Partial pressure of oxygen in blood (PO2)
- Temperature
- Blood pH
- The partial pressure of carbon dioxide (PCO2) + therefore concentration of H+ ions
- Blood concentration of BPG (2,3-Biophosglycerate) produced by RBC
How much CO2 do respiring cells produce per minute?
200ml
What is carbaminohaemoglobin?
CO2 binds to globin portion of molecule
What are the main (2) determining factors of PaO2 & PaCO2?
- The amount of air reaching the alveoli (V)
- The amount of blood reaching the alveoli (Q)
What is a ‘shunt’?
An area with no ventilation
What is ‘dead space’?
An area with no perfusion
