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Flashcards in oxygen transport Deck (24)
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1

at alveoli, how are o2 and co2 exchanged?

rapid simple diffusion (high to low [ ])

2

partial pressure

pressure of an individual gas in a mixture proportional to [ ] = %xtotal air pressure (ex % of 760 mmHG)

3

atm air is a mixture of

79% nitrogen 21% oxygen .04% co2

4

henrys law for gases in solution...

the higher the solubility, the less pp the gas exerts PP=[ ] dissolved gas/solubility

5

gas diffusion rate is inversely proportional to

mol weight of gas diffusion distance

6

gas diffusion rate is directly proportional to

difference in pp solubility of gas in fluid surface area of fluid T of fluid

7

solubility coefficient for O2

.024

8

SOLUBILITY COEFFICIENT FOR co2

.57 20x more soluble than o2 (.024)

9

Hb allows

blood to transport 30-100x more O2 than could be carried as dissolved gas

10

how much o2 is carried on Hb and how much is dissolved in blood?

Hb - 97% dissolved - 3%

11

Hb structure

2 alpha and 2 beta chains, each has a heme group with a central iron that reversibly binds O2

12

cooperativity

1 o2 atom binding increases binding affinity for additional molecules in Hb chain heme groups

13

bohr effect

increased CO2 leads to increased H+[ ] leads to greater release in oxygen (less hb affinity) at peripheral tissues (occurs in exercise)

14

when do you see bohr effect?

exercise

15

Hb oxygen binding is inversely related to

acidity and [co2]

16

to decrease oxygen affinity, -[H+] -[co2] -T -23BPG

increase them all

17

chloride shift

rbc chloride content is higher in venous circulation than arterial because the bicarbonate-chloride ion echanger transports bicarbonate into blood plasma and chloride ions into rbc

18

haldane effect

oxygen binding to Hb causes co2 to be released from blood ---- reversal of bohr -- allows o2 to be picked up oxygen makes hb more acidic --> Hb releases H H combines w bicarbonate to make carbonic acid --> water co2

19

henderson hasselbach eq

determines pH of solution from pCo2 and HCO3 pH = pK + log ([HCO3]/(s x pCO2)

20

carbonic anhydrase

rbc enzyme that catalyzes rxn of co2 and water to form bicarbonate and H - occurs in venous blood

21

resp. acidosis vs alkalosis

acidosis - pco2 rises due to suppression of ventilation or decreased perfusion (ards and anesthetic) alk - pco2 decreases due to increased ventilation (aspirin, high altitude)

22

what compensates for respiratory pH changes?

renal function

23

how does renal system compensate in acidosis? alkalosis?

acidosis - increases HCO3 to return to normal pH alk - renal function decreases HCO3-

24

bicarbonate buffer system

keeps blood plasma pH within small range (7.37venous - 7.41 arterial) despite CO2 changes acid-base homeostasis using carbonic anhydrase