Flashcards in Respiratory Physiology Deck (126)
What kind of condition are Asthma, COPD and Lung cancer?
What kind of conditions are pulmonary fibrosis, pneumothorax, scoliosis (intrinsic/extrinsic)?
Pulmonary fibrosis = intrinsic restrictive
Pneumothorax, scoliosis = extrinsic restrictive
What extra muscles do you use for inspiration with increasing effort?
What extra muscles do you use for expiration with increasing effort?
What does a spirometer measure?
Volume of air in and out of lungs during ventilation
What happens to the TLC, VC, FRC and RV in restrictive conditions?
What happens to TLC, RV, and FRC in obstructive conditions?
RV is increased (cant get last bit of air out)
TLC is reduced (COPD) or increased (emphysema)
FRC is increased in emphysema
Are pulmonary fibrosis, kyphyscoliosis and circuferential burn associated with increased or reduced compliance?
Reduced (less stretchy)
Is emphysema associated with increased or reduced compliance?
Increased (more stretchy)
What is Laplaces law?
pressure = (2x surface tension)/radius of bubble
Why does surfactant prevent atelectasis?
Spread thicker in smaller alveoli so decreases the surface tension more greatly in them than larger alveoli so you end up with the same pressure
What is the make up of surfactant?
In what syndrome is surfactant deficient?
Respiratory distress syndrome
From laminar flow to turbulent flow by how much is the work increased?
Power of 2
How much of energy expenditure is spent on respiration in health at rest>?
How much energy expenditure is spent on respiration at maximum hyperventilation?
How is work of respiration minimised in restrictive conditions?
Rapid slow volume breaths
How is work of respiration minimised in obstructive conditions?
Large volume, slow breaths
Why are breath sounds greater in larger airways than smaller airways?
Higher flow rate and therefore more turbulent flow in large airways
What is Dalton's law about partial pressure of gas?
Partial pressure = total pressure x fraction of that gas
Why is partial pressure of oxygen in the alveoli lower than in inspired air? 3
1) Inspired air humidified
2) O2 taken up into blood stream while CO2 is added
3) Body consumes more O2 molecules than is produces CO2
What is the relationship of partial pressure of a gas and its solubility?
Partial pressure of a gas in solution is inversely proportional to its solubility
Why in someone with pulmonary fibrosis would the partial pressure of oxygen in the blood decrease if rate of respiration and heart rate increased?
Capillary transit time is shorter than the time take for diffusion of O2
What is carbon monoxide diffusing capacity used for?
To establish if someone with reduced exercise capacity has a problem with diffusion across the alveoli
What is adult respiratory distress syndrome?
Inflammatory process, difficult to distinguish from pulmonary oedema
What muscle holds the tongue against the palate in nasal breathing?
What muscle lifts the soft palate away from the back of the pharynx in mouth breathing?
How does the pharyngeal dilator reflex work?
1) Pressure receptors in the mucosal lining of the pharynx detect air flow
2) Send a message to the brainstem
3) Brain stem causes pharyngeal muscle contraction to open pharynx and allow air flow
What is the problem in obstructive sleep apnoea?
Pharyngeal dilator reflex doesnt work properly or pharynx cant be help open (fat deposits around the muscle in obesity)