CGIER 31 - Hyperbaric gas toxicities

Question 1

out of the 1 L of blood in the lungs how many of that is in the alveolar capillary beds

Answer 1

70ml

Question 2

why must gas transport be fast

Answer 2

blood remains in Alveolar capillary bed ACB for 1 second

passive diffusion

Question 3

what process controls transport of O2 and CO2 in and out of blood

Answer 3

diffusion

Question 4

diffusion

Answer 4

a passive process that pushes atoms and molecules from regions of high concentration to regions of low concentration until Equilibrium is established

Question 5

velocities of gas molecules

Answer 5

early the speed of sound 344ms-1^

Question 6

why is it good that no energy is lost during elastic conditions

Answer 6

all molecules would continually lose velocity and end up congregating (liquefying) at the bottom of their containers.

Question 7

how does the partial pressure of oxygen change as we reach the lungs

Answer 7

decreases gradually

Question 8

Lungs completely empty during expiration. True or False

Answer 8

False - retain 30% of max. inspired volume ~5-6 L

Question 9

Tidal Volume

Answer 9

Only about 500ml is exchanged during normal respiration

Question 10

Spirometry

Answer 10

measurement of respiratory volumes

Question 11

anatomical dead space

Answer 11

the end of inspiration, air in trachea and bronchi is not exposed to pulmonary capillaries.

Question 12

why do snorkellers have a harder time breathing?

Answer 12

snorkelling extend sADS by about 70-80 but tidal volume is the same - the amount of air you breath in is the same

Question 13

why is surface tension important in lungs

Answer 13

prevents lungs from deflating completely

mediated by surfactant molecules - inert hydrocarbon part but polar end

Question 14

cohesive forces

Answer 14

Weak forces of attraction exist between similar molecules

creates interesting effects at the surface of a liquid.

Question 15

what does it mean if there are cohesive forces in a liquid atom w/ no net force

Answer 15

equally attracted to all molecules in all directions

Question 16

describe cohesive forces for atoms on surface of liquid

Answer 16

only attracted by those below and so feels a net downwards force.

Question 17

surface tension

Answer 17

Any bump formed on the liq. surface is dragged back into the bulk by this force
atoms are trying to reduce surface area

Question 18

unit of measurement for surface tension

Answer 18

newton/metre = γ

Question 19

why will isolated volumes of liquid always try to form a sphere

Answer 19

surface tension - always try to minimise surface area

the smallest surface area is a sphere

Question 20

define γ

Answer 20

the amount of work needed to increase the surface area of a liquid by 1 unit area