mech of breathing

Question 1

collapsing tendancy

Answer 1

elasticity of ct (1/3) and all Surface tension (2/3)

Question 2

surface tension

Answer 2

electrostatic forces in water, water molecules at surface pull down only, contract

Question 3

ST in alveoli

Answer 3

spherical, ST pulls inward causing interior pressure.

Question 4

alveolar pressure varies with what?

Answer 4

size! smaller require greater P to keep open

Question 5

surfactant

Answer 5

lipid plus protein, type II cells, allows ST to vary between alveoli, so one pressure can keep them all open

Question 6

compliance

Answer 6

change in volume with change in transmural P, stiffness of wall dictates change in volume.

Question 7

compliance is low at

Answer 7

max volume, max stretch.

Question 8

hysteresissi

Answer 8

complains in is different from compliance out (out requires less pressure).

Question 9

saline vs water and compliance

Answer 9

saline has no hysteresis- no ST, more compliance

Question 10

diseases that reduce complaince

Answer 10

fibrosis

Question 11

diseases that increase compliance

Answer 11

emphysema

Question 12

how can the lungs inflate

Answer 12

positive or negative pressure

Question 13

airway R measure

Answer 13

FEV1/FVC (obstructive less than .7)

Question 14

Ptm

Answer 14

Palv-Pip, keeps lungs expanded, usually around 4

Question 15

solubility in plasma

Answer 15

proportional to partial pressure

Question 16

diaphragm

Answer 16

main breathing muscle, contracts for inspiration

Question 17

forced inspiration muscles

Answer 17

intercostal scalene

Question 18

forced expiratory muscles

Answer 18

intercostal diaphragm abs