Respiratory Intro

Front 1

oxygen transport cascade

Back 1

O2 supply (air)
lung alveoli
alveolar capillaries
Hb
Hb-bound O2
tissue capillaries
Mi
cellular O2 demand

Front 2

P

Back 2

pressure

Front 3

A

Back 3

alveolar

Front 4

E

Back 4

expiratory

Front 5

a

Back 5

arterial

Front 6

v

Back 6

venous

Front 7

c

Back 7

capillary

Front 8

F

Back 8

decimal fraction

Front 9

I

Back 9

inspired

Front 10

E'

Back 10

end-expiratory

Front 11

C

Back 11

concentration

Front 12

_
v

Back 12

mixed (mean) venous

Front 13

c'

Back 13

end-capillary

Front 14

ambient conditions of
O2
CO2
N2
H2O

Back 14

O2 20.93%
CO2 0.03%
N2 79.01%
H2O no water vapor

Front 15

Daltons Law of partial pressures

Back 15

Px = Fx (PB-PH2O)
PH2O = 40 mmHg

Front 16

boyles law

Back 16

P1 x V1 = P2 x V2

volume of gas is inversely related to its pressure

Front 17

charles' law

Back 17

V1/T1 = V2/T2

volume of gas is directly related to its temperature

Front 18

general gas law

Back 18

PV = nRT

(P1xV1)/T1 = (P2xV2)/T2

Front 19

henrys law of gas solubility

Back 19

Cx = (Kx)(Px)

molecules moving from gaseous to aqueous phase dissolve to their maximal conc according to this relationship

Cx = dissovled conc of substance X
Kx = temperature dependent solubility coefficient of substance X

Front 20

[H2CO3] =

Back 20

40 x 0.03
=1.2 mM

Front 21

whole blood contents

Back 21

cells and plasma

Front 22

centrigued blood layers (bottom to top)

Back 22

packed cells (RBCs)

light colored buffy coat of leukocytes and platelets

on top: plasma with lowest specific gravity

Front 23

plasma vs serum

Back 23

plasma: w/ fibrinogen (clotted form)

serum: w/o fibrinogen

Front 24

nL range of hematocrit

measured or derived

Back 24

38-47%

m

Front 25

nL range of adult [Hb]

measured or derived

Back 25

12-16 g/dL (100 mL)

m

Front 26

nL # of RBCs

measured or derived

Back 26

3.5 - 6.0 x 10^6

m

Front 27

mL range of MCV

equation

measured or derived

Back 27

mean cell volume
80-90 fL/cell

d
(Hct)*(10)/(#RBC)

Front 28

mL range of MCH

equation

measured or derived

Back 28

mean cell Hb content
25-30 pg/cell

d
([Hb])*(10)/(#RBC)

Front 29

mL range of MCHC

equation

measured or derived

Back 29

mean cell Hb concentration
32-35%

d
([Hb])*(100)/(Hct)

Front 30

O2 is carried in the blood in two forms

Back 30

dissolved or bound to Hb (most important)

Front 31

characteristics of Hb

Back 31

each subunit contains a heme moiety which is iron-containing porphyrin

iron is in ferrous state which binds to O2 (Fe+2)

each subunit has a polypeptide chain; 2 of the subunits has alpha chains and two of subunits have B chains

normal adult: alpha2beta2

Front 32

fetal Hb

Back 32

B chains are replaced by gamma chains alpha2gamma2

-O2 affinity is higher than adult becuase DPG binds less avidly
-b/c O2 affinity is higher, O2 moves from mother to fetus

Front 33

O2-binding capacity of blood

Back 33

max amount of O2 that can be bound to Hb in blood

dep on [Hb] in blood

limits amount of O2 that can be carried in blood

measured at 100% saturation

Front 34

O2 content in blood

Back 34

total amount of O2 carried in blood, including bound and dissolved O2

depends on [Hb], PO2, and P50 of Hb

O2 content = (O2binding capacity x %saturation) + dissolved O2

Front 35

O2 content =

Back 35

amoutn of O2 in blood

Front 36

O2 binding capacity =

Back 36

maximal amount of O2 bound to Hb at 100% saturation

Front 37

% saturation

Back 37

% of heme groups bound to O2

Front 38

dissolved O2 =

Back 38

unbound O2 in blood

Front 39

Hb combines rapidly with...

Back 39

and reversibly with O2 to form oxyHb

Front 40

Hb-O2 dissociation curve is a plot of

Back 40

saturation of Hb as a function of PO2

Front 41

At a PO2 of 100 mmHg
(i.e. ?)
what is the Hb saturation

Back 41

arterial blood

100% saturated: O2 is bound to all 4 heme groups on all Hb molecules

Front 42

At a PO2 of 40 mmHg
(i.e. ?)
what is the Hb saturation

Back 42

mixed venous blood

75% saturated: on average, three of 4 heme groups have O2 bound

Front 43

At a PO2 of 25 mmHg

what is the Hb saturation

Back 43

50% saturated

P50 = 2 of 4 hemes have O2 bound

Front 44

positive cooperativity facilitates

Back 44

increase in affinity for the next O2 molecular as each O2 molecule binds facilitates the loading of O2 in the lungs and unloading of O2 at the tissues

Front 45

alveolar gas PO2

Back 45

100 mmHg

Front 46

what facilitates the diffusion process

Back 46

the very high affinity of Hb for O2 at a PO2 of 100 mmHg facilitates the diffusion process

by tightly binding O2, the free O2 conc and O2 parital pressure are kept low, thus maintaning the partial pressure gradient

Front 47

maintenance of O2 diffusion in peripheral tissues

Back 47

cells consume O2 for aerobic metabolism, keeping the tissue PO2 low therefore O2 keeps diffusing to tissue from arterial blood

Front 48

causes of Hb-O2 dissociation curve to shift RIGHT

Back 48

inc PCO2
dec pH
inc temp
in 2,3-DPG

Front 49

causes of Hb-O2 dissociation curve to shift LEFT

Back 49

dec PCO2
inc pH
dec 2,3-DPG
HbF

Front 50

what does it mean when the Hb-O2 dissociation curve shifts to the RIGHT

Back 50

affinity of Hb for O2 is decreased

P50 is increased, and unloading of O2 from arterial blood to tissue is facilitated/easier

for any level of PO2, the % saturation of Hb is decreased

Front 51

bohr effect

Back 51

increasing concentration of protons and/or carbon dioxide will reduce the oxygen affinity of hemoglobin (shifting graph to RIGHT)

Front 52

bohr effect in exercise

Back 52

during exercise, the tissues produce more CO2 which decreases tissue pH, which reduces the O2 affinity of Hb, stimulating O2 delivery to exercising muscles

Front 53

temperature effect in exercise

Back 53

increase in temperature for high demand tissue will dec affinity of Hb for O2 and faciliate delivery of O2 to tissues during this period of high demand

Front 54

increases DPG concentration effect on curve

Back 54

DG binds to B chain of deoxyHb and decreases affinity of Hb for O2

Front 55

adaptation of people living at high altitude

Back 55

chronic hypoxemia
-increased synthesis of 2,3-DPG, which binds to Hb and facilitates the unloading of O2 in the tissues

Front 56

what does it mean when the Hb-O2 dissociation curve shifts to the LEFT

Back 56

-affinity of Hb for O2 is increased

-P50 is decreased and unloading of O2 from arterial blood into tissues is more difficult

-for any level of PO2, the percent saturation if increased

Front 57

HbF effect on curve

Back 57

to the LEFT

-decreased binding to 2,3DPG results in increased affinity of HbF for O2, decreased P50, and a shift to LEFT

Front 58

CO effect

Back 58

CO occupies O2 binding sites of Hb decreasing O2 content in blood

AND

increases affinity of remaining sites for O2 therefore decreases unloading and a shift to the LEFT

Front 59

physical findings of CO poisoning

Back 59

ruby lips and ruddy complexion
[Hb-CO]>40% is usually fatal

Front 60

tx for CO poisoning

Back 60

hyperbarric chambers

exposing pts to 2-3 atmpospheres of 100% O2

Front 61

transport of CO2 as HCO3

Back 61

CO2 is genertated in tissues and diffuses freel into venous plasma and then into RBCs

in RBCs: CO2 combines with H2O to form H2CO3 (catalyzed by carbonic anhydrase)

-H2CO3 dissociates to H and HCO3

HCO3 leads RBCs in exchange for Cl (chloride shift) and is transported to lungs in the plasma

H is buffered inside the RBCs by deoxyHb

in the lungs: all of the above by reversed:
HCO3 enters RBCs in exchange for Cl, combines with H to form H2CO3 which is decomposed to CO2 and H2O and CO2 is expired

Front 62

The respiratory quotient (RQ) is calculated from the ratio:

Back 62

RQ = CO2 eliminated / O2 consumed

Front 63

explain compensation

Back 63

if metabolic is messed up the respiratory will try to compensate therefore deviates from normal

if respiratory stays normal, it is not trying to compensate