Orientation to Airway Booklet Flashcards
What are the functions of the upper airway?
- Filter
- Warm
- Humidify air
–> Prevent infection
– > Aid ventilation - Prevents introduction of foreign bodies and aspiration through epiglottis
What is the function of the lowr airways?
Primary gas exchange
What is ventilation?
Process of inhaling and exhaling air for gaseous exchange
Where is the primary area for gas exchange?
Alveoli
Outline process of negative pressure ventilation
- Intercostal, abdominal and diaphragm muscles contract
- Increases volume of chest cavity
- Decreases pressure (-P gradient)
- Air is drawn in
- GE occurs
- Intercostal, abdominal and diaphragm muscles passively relax
- Decreases volume of chest cavity
- Increases pressure (+P gradient)
- Air exits
What areas of the brain control breathing and ventilation
- Medulla Oblongata: muscle stimulation
- Brainstem: detection of chemoreceptor changes (determines rate and depth of breathing)
What does the oxyhaemoglobin dissociation curve show?
- Relationship between partial pressure of oxygen (PaO2) and % of haemoglobin saturation (SaO2)
What does a shift to the left in the oxyhaemoglobin dissociation curve do?
Increases O2 binding affinity on Hb
What factors cause a shift to the left in the oxyhaemoglobin dissociation curve?
Increase O2 binding affinity of Hb
- Decreased temp
- Decreased 2-3 DPG
- Decreased [H+] / increased pH
- Decreased pCO2
- CO
What factors cause a shift to the right in the oxyhaemoglobin dissociation curve?
Decreased O2 binding affinity of Hb
- Increased temp
- Increased 2-3 DPG
- Increased [H+]/decreased pH
- Increased pCO2
What is 2-3 DPG and what is its relationship to the oxyhaemoglobin dissociaton curve?
- Intermediate of glycolysis in RBCs which is rapidly consumed under normal O2 tension
- Hypoxia causes 2-3 DPG to significantly accumulate
–> Increased 2-3 DPG shifts oxyhaemoglobin curve to the right
–> decreases O2 binding affinity of Hb
