Mechanics of breathing and gas exchange Flashcards Preview

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Flashcards in Mechanics of breathing and gas exchange Deck (26):
1

Dalton's law of partial pressure

Partial pressure of a gas in a mixture of gases if it occupied the total vol o the mixture

2

PO2 mixed venous blood

40mmHg

3

PCO2 mixed venous blood

46mmHg

4

PO2 systemic arterial blood

100mmHg

5

PCO2 systemic arterial blood

40mmHg

6

What kind of oxygen produces partial pressure

Dissolved

7

Henry's law

Conc. of dissolved O2 proportional to PP of dissolved O2

8

Description of Hgb

Globular protein w/ 4 subunits each contains one reduced iron Fe2+ and 4 polypeptide chains=2 alpha and 2 beta

9

Property of heme that increases affinity of subsequent binding oxygens

positive cooperativity

10

normal adult Hb

HbA

11

Methemoglobin

contains oxidized iron Fe3+, doesn't bind O2

12

What causes Methemoglobin

Nitrites
sulfonamides
Genetic; decreased methemoglobin reductase enzyme in RBC

13

How can you treat Methemoglobin to make it functional

Methylene blue

14

Fetal Hb, HbF

Higher affinity than HbA to facilitate most of O2 from mom to fetus,
Hv 2 alpha and 2 gamma chains, replaced over far yr

15

HbS

Abnormal beta chain in sickle cell anemia. Lower affinity than HbA

16

Deoxyhemoglobin

Hb not bound to O2

17

Oxyhemoglobin

Hb bound to O2

18

Fully saturated Hb

all heme portions combine w/ O2

19

Primary factor in determining Hb saturation

PO2; high blood PO2 = high Hb saturation. Hb loads up at the lungs and unloads at the titssues

20

T/F: CO2 is more soluble than O2

T, 20x more

21

How is CO2 transported in the blood

Dissolved - 5%
Bound to Hb - 3%
Bicarb - 90%

22

CO2 bound to Hb

Carbaminohemoglobin

23

T/F: Reduced Hb has a greater affinity for CO2 than O2

T, this is what facilitates unloading at the tissues and pick up of CO2

24

How does dissociated bicarbonate get across the RBC membrane

Cl-/HCO3- exchanger - band 3 protein(same charge so balanced) and carried to the lungs in venous blood

25

What buffers the H+ produced from dissociation of dissolved CO2 in the RBC

Deoxyhemoglobin

26

Haldane effect

CO2 released from the dissociation of carbonic acid to carbon dioxide and bicarb. occurs in the lungs