Flashcards in Function of the Respiratory System Deck (35)
What are the functions of the respiratory system?
-Exchange of air in the lungs
-O2 and CO2 exchange in the alveoli
What are some of the secondary functions of the respiratory system?
Barrier - mucus clearance
What are the parts of the upper airway?
What are the parts of the lower airway?
What is the function of the upper airway?
Conditions the air by warming and humidifying it
Where is most of the resistance in the respiratory tract found?
Nose. It makes up 50% of the total airway resistance.
What is the function of the nose?
It filters out large particles in the air
How is the total airway resistance reduced drastically?
What must be done when vocal cord edema prevents intubation?
What is the function of the partitioning of the lungs into lobes?
It allows for movement without hurting the functionality of the lungs as it allows them to slide over one another.
Where does the trachea split?
What are conducting airways?
They are to transport gas and lack membranes for gas exchange.
About how many generations does the conducting airway make up?
Where is the transition zone?
Around generation 17-19
What are the features of the alveoli that make it ideal for gas exchange?
They are very thin with a large area which makes them ideal for diffusive gas exchange with the pulmonary capillary blood.
What are Type I alveolar cells?
They are the main gas exchange cells with thin membranes and comprise around 97% of the alveoli cells.
What are Type II alveolar cells?
They produce surfactant and make up 2-4% of the cells.
How does surface tension and the alveolar radius affect the inward pressure?
Small radius alveoli would have high pressures and collapse, while large ones would become distended.
How is the problem of the high surface tension in the alveoli addressed?
Type II alveolar cells make surfactant, which decreases the surface tension
How does surfactant deal with different sized alveoli?
Small alveoli contain more surfactant per surface are than larger alveoli, which permits maintenance of alveoli with different sizes.
How is the stability of the alveoli maintained?
Alveoli are mechanically tethered and this traction force opposes the tendency to collapse.
What are the structures that allow for collateral ventilation?
Channels of Martin
Channels of Lambert
Pores of Kohn
What are the two blood supplies to the lungs?
Describe the bronchial circulation with arteries and veins.
-Receives around 1% of the cardiac output and it goes to the terminal bronchioles
-1/3 returns to the RA via the azygous/hemiazygous/intercostal veins
-2/3 drains into the pulmonary circulation and contributes to the venous admixture
How does impaction work in deposition?
Large particles are trapped in the nasopharynx and impacted.
How does sedimentation work in deposition?
Medium particles are trapped in the small airways.
How does diffusion work in deposition?
Very small particles are moved by diffusion through the alveoli.
What are the components of the mucociliary clearance system?
What is the function of the mucus layer?
It lies on top of the periciliary fluid and entraps inhaled particles.