Cadriopulm mgmt Session 1 Flashcards
What are the components of the oxygen transport system
- Inspired oxygen and quality of air
- Airways
- Lungs and chest wall
- Diffusion
- Perfusion
- Myocardial function
- Peripheral Circulation
- Tissue extraction and utilization of oxygen
- Return of partially desaturated blood and CO2 to lungs
- Oxygen Delivery - DO2
- Oxygen consumption - VO2
- Oxygen extraction ratio - OER (23% at rest)
What regulates DO2?
Demand of tissues
At rest, how may times more is the supply of DO2 vs the demand?
3-4x
What determines hemoglobin’s affinity for O2?
pH and temperature
Why is the balance of intravascular and extravascular fluid important?
An imbalance can impact the electrolytes and lead to impaired organ function
What is the % nitrogen and % oxygen in the air?
Nitrogen- 79%
Oxygen- 21%
Why is poor air quality a problem for the lungs?
Poor air quality interferes with the respiratory tract filtering and leads to inflammation of alveolar capillary
Why is humidity important for inspiration?
Dry environments cause a loss of mucus covering which can lead to erosion and infection; alveoli need moisture to help with gas exchange
What are the components of the upper and lower respiratory tracts?
Upper: Nasal cavity, pharynx, larynx
Lower: Trachea, primary bronchi, lungs
What is the role of cilia in the respiratory tract?
Catch cilia and help push it back out
How does the diaphragm regulate inspiration?
When the diaphragm contracts, a negative space is created in the lungs and air flow in (inhalation). In expiration, the diaphragm relaxes and causes a positive pressure, causing air to flow out.
What problem is caused when the lungs don’t expand symmetrically?
The lesser moving side pools mucus and causes pneumonia
What muscles are involved in inspiration?
External intercostals - elevate ribs
Diaphragm - depresses the inferior wall of the thoracic cavity
What muscles are involved in active expiration (typically expiration is a passive process)
Internal intercostals - compress and lower ribs
Abdominals - Compress abdominal cavity which elevates the abdominal organs and passively elevates the diaphragm
Define diffusion
The transfer of oxygen from alveolar sacs to pulmonary circulation
List 5 factors that affect diffusion
- SA of alveolar capillary membrane
- Diffusing capacity of alveolar- capillary membrane (thick vs thin membrane)
- Pulmonary capillary blood volume (more blood = more oxygen)
- Ventilation/ perfusion ratio (Vol O2 breathed in vs % O2 used)
- Transit time of blood in alveolar capillary