respiration 2

Question 1

what is compliance?

Answer 1

measure of elasticity of lungs/ distensibility

Question 2

what is compliance equation?

Answer 2

C=ΔV/ΔP

Question 3

what if there is high or low compliance?

Answer 3

high - difficulty expiring (emphysema)

low - difficulty inspiring e.g. (fibrosis)

Question 4

wat is anatomical component of lung recoil?

Answer 4

elastic nature of cells and ECM

Question 5

what is laplaces equation?

Answer 5

P = 2T/r

air flows from smaller aveoili to larger aveoli (large aveoli have a lower pressure)

Question 6

how is the problem of smaller aveoli collapsing prevented?

Answer 6

by surfactant production

Question 7

what produces surfactant?

Answer 7

type 2 pneumocytes

Question 8

what does surfactant do?

Answer 8

acts to reduce surface tension

Question 9

what is surfactant composed of?

Answer 9

lipids and proteins

Question 10

what are lung volumes measured by?

Answer 10

spirometer

except lung residual volume

Question 11

what is physiological dead space?

Answer 11

volume of lungs not participating in gas exchange

Question 12

how can residual volume be measured?

Answer 12

helium dilution

Question 13

how does flow of air into lungs compare to pressure gradient and resistance?

Answer 13

air flow into/ out of lungs in PROPORTIONAL to pressure gradient but INVERSELY proportional to resistance

Question 14

what is poiseilles law?

Answer 14

Airway resistance is proportional to gas viscosity and the length of the tube but is inversely proportional to the fourth power of the radius.

Question 15

do small airway changes have impact on resistance/flow?

Answer 15

YES

Question 16

what is airway resistance in normal individual?

Answer 16

1.5cm H2O .s.litres-1

Question 17

what factors impact airway resistaance?

Answer 17

oedema (swellings + narrowing of airways)
airway collapse (narrows airways)
mucous secretion (reduce lumen diameter + increased resistance)

Question 18

how is bronchial smooth muscle controlled?

Answer 18

autonomic nervous system (parasympathetic and symapthtic and humoral responses)

Question 19

how can acetylchloline cause constriction of airways?

Answer 19

PARASYMPATHETIC Ach released from vagus nerve, acts on muscurinic receptors - CONSTRICTION

Question 20

what does histamine do?

Answer 20

cause constriciton of airways

Question 21

how does sympathetic NS cause bronchial dilation?

Answer 21

release of noradrenaline from nerves - weak agonist - dilation

Question 22

how does adrenaline vary to adrenaline in airways ?

Answer 22

(circulating blood) adrenaline is a stronger agonist leads to dilation

Question 23

when is histamine released?

Answer 23

during inflammatory processes