Dynamic Respiration Lecture 10

Question 1

Airway resistance depends on (2)

Answer 1

diameter (smooth muscle contraction via autonomics, changes in secretions, volume of lung)
viscosity of the inspired gas

Question 2

80% of the resistance to airflow in the lungs can be found where?

Answer 2

in the largest conducting parts of the air system, up to the 7th generation of bronchioles

Question 3

radial traction definition

Answer 3

small units tethered to the larger matrix around them; e.g. alveoli in the lung

Question 4

cross-sectional airway area is determined by (3)

Answer 4

1) Lung Volume
2) Lung elasticity
3) bronchial smooth muscle tone

Question 5

F-V loops can be affected by: (3)

Answer 5

Lung volume
Airflow resistance
Elastic recoil

Question 6

Forces active during expiration (3)

Answer 6

Elastic contraction
Expiratory muscle contraction
Airflow resistance

Question 7

expiratory effort at high volume vs. at low volume

Answer 7

at high volume increased expiratory effort will have the effect of increasing flow, but as the volume drops off, increased effort of expiration is counter-acted by contraction of the airways resulting in no significant increase in flow.

Question 8

Equal Pressure Point and Physiological significance

Answer 8

The point in the airways where the airway pressure equals the pleural pressure causing constriction in the airways. Once this point is reached, increased expiratory force produces no more greater flow, the point of effort independence

Question 9

Curve shifts due to restrictive and obstructive diseases (F-V curves): two definitional words regarding obstructive shift

Answer 9

Ob. diseases cause breakup of tissue which reduces elasticity and diminishes the forces holding airways open; this makes the maximum airflow significantly less than normal, and causes a “scooped out” shape on the effort independent portion of the expiratory F-V loop. This is called the “expiratory coving”

Question 10

Emphysema expiration is difficult because…

Answer 10

Ppl is so high that the bronchioles and alveoli become compressed, meaning that air gets trapped in the lungs and as a result the RV and TLC go up considerably

Question 11

Two methods that emphysema patients use to make their expiration better

Answer 11

breathing out slowly, by lowering the velocity they move the EPP higher in the neck where there is less tendency for collapse
operating at high lung volumes where the radial traction can offset the decrease in the airways

Question 12

Parasympathetics cause

Answer 12

bronchoconstriction; along with allergens/irritants and histamine

Question 13

Sympathetic receptors type and drug/activators

Answer 13

B2 receptors, NE weak, Epi strong; albuterol is the drug