L03 - Gas Laws and VE Flashcards
What are some non-respiratory lung functions?
- Defensive
- Metabolic
- Endocrine
- Haemotologic
- Immunologic
- Thermoreg
- Water-elim
- Phonation
What is the metabolic rate?
How much O2 we consume and how much CO2 we produce at any one moment (it varies)
Formula for RQ?
RQ = VCO2/ VO2
What is the RQ value is only carbohydrate is metabolised?
RQ = 1.0
What is the RQ value if only protein is metabolised?
RQ = 0.81
What is the RQ value if only fat is metabolised?
RQ = 0.7
What is a typical RQ value for a mixed diet?
RQ = 0.8
Definition of barometric pressure (PB)
The pressure exerted by the weight of gas molecules in the atmosphere above the point of measurement
Definition of dead space?
The volume of gas within the resp system in which gas exchange does not occur
Formula for physiological dead space?
Physiological dead space = anatomic + alveolar dead space
What are the factors affecting anatomic dead space? (VD)
- The size of the subject; the larger the person, the larger the anatomical dead space
What are the factors affecting alveolar dead space?
- Too small to be measurable in normals
Increased significantly in certain lung diseases (due to under-perfusion of affected alveoli)
What do we use to measure the metabolic rate?
Oxygen consumption (V^.O2) - Flow of oxygen with time (ml/ min) - The dot added to the top of the V is a time derivative therefore flow of oxygen with time
What is the basal metabolic rate?
The volume of oxygen required when at rest
‘number of calories required to keep body functioning at rest’
What is the approx value of a human’s basal metabolic rate?
250ml/O2/min
What is the daily average of oxygen consumption for humans?
1000ml/O2/min
What is the respiratory quotient (RQ)
- Steady state conditions
- Depends only on the type of food being metabolised
At which generation does the trachea split into the right and left primary bronchi?
Generation 1
How many generations of airways are there?
23 generations
Which generations make up the conducting zone ?
The first 16 generations
What is different about the airways in the conducting zone?
They do not allow for gaseous exchange to occur on their surfaces (too thick)
Which generations make up the transitional and respiratory zone?
Generations 17-23
Why can the airways in the transitional zone allow for gaseous exchange but the airways in the conducting zone cannot?
The airways in the transitional zone are thinner than the airways in conducting zone
What are the airways in the transitional zone?
- Respiratory bronchioles
- Alveolar ducts
- Alveolar sacs
