A&p2 Unit3/5

Front 1

decreased oxygen at the tissue level

Back 1

hypoxia

Front 2

no oxygen at the tissue level

Back 2

anoxia

Front 3

4 major types of hypoxia

Back 3

-hypoxemic hypoxia
-hypoperfusion hypoxia
-anemia hypoxia
-histotoxic hypoxia

Front 4

does hypoxemia itself lead to tissue hypoxia?

Back 4

no, as long as it is mild, there will be an increase in cardiac output that delivers adequate amounts of oxygen

Front 5

failure of adequate amounts of oxygen to reach the pulm cap blood is ?

Back 5

hypoxemic hypoxia/hypoxic hypoxia

Front 6

conditions causing hypoxemia hypoxia

Back 6

high altitude
hypoventilation
obstructive pulm diseases
anything impairing diffusion of oxygen across the pulm membrane, such as: fibrotic lung disorders, pulm edema, chf

Front 7

hypoxia resulting from failure to deliver adequate amts of oxygen to tissues b/c of reduced blood flow

Back 7

hypoperfusion hypoxia/stagnant hypoxia, circulatory hypoxia

Front 8

in hypoperfusion hypoxia, do you have problems oxygenating the blood at pulm caps?

Back 8

no, it is just not enough pulm cap blood getting to the tissues

Front 9

causes of hypoperfusion hypoxia are:

Back 9

severe hemorrhage-lack of bld
high PEEP settings-decreased VR, decreased CO

Front 10

hypoxia resulting in too little functioning Hgb available to transport adequate amts of oxygen to the tissues is?

Back 10

anemic hypoxia

Front 11

causes of anemic hypoxia

Back 11

-decrease in RBCs/Hct
-decrease in Hgb present w/i the RBC: hct is normal,
-Carbon monoxide poisoning: some of Hgb is bound to CO than to Oxygen

Front 12

hypoxia resulting from toxicity to the tissues: despite adequate amts of oxygen, tissues can't use it

Back 12

histotoxic hypoxia

Front 13

causes of histotoxic hypoxia

Back 13

cyanide poisoning
nipride toxicity

Front 14

sudden and severe hypoxia

Back 14

fulminating hypoxia

Front 15

heme protein naturally occurring in muscle

Back 15

myoglobin

Front 16

How does myoglobin differ from Hgb?

Back 16

-myo can bind only 1 molecule of oxygen, Hgb binds 4
-myo has much greater affinity for oxygen

Front 17

what is referred to as an oxygen reserve/reservoir?

Back 17

myoglobin d/t it picking oxygen up after it is released from tissues, and it shuttles it to the mito where it utilizes it as an electron acceptor

Front 18

causes of arterial hypoxemia

Back 18

-hypoventilation
-diffusion limitation: difficulty transferring across pulm memb
-shunts
-ventilation/perfusion mismatch

Front 19

resting CO2 production

Back 19

200ml of CO2/min

Front 20

how much CO2 is passing through systemic per liter?

Back 20

40ml CO2/L

Front 21

for every 100mls of blood going through tissue capillaries, how much CO2 is picked up? how about in lungs

Back 21

4 mls picked up by tissue capillaries, 4 mls released to alveoli

Front 22

4 ways of transport of CO2 by plasma

Back 22

-CO2 physically dissolved in the plasma
-CO2 transported as carbonic acid
-CO2 transported as Bicarb ions formed in plasma
-CO2 transported as carbamino cmpds

Front 23

what percent accts for the CO2 transported from the tissues to the lungs in the dissolved state?

Back 23

5-10%

Front 24

amt of CO2 physically dissolved in the plasma is directly proportional to?

Back 24

-CO2 solubility coefficient in plasma at body temp (37)
-partial pressure of CO2 in plasma (Henry's law)

Front 25

solubility coefficient of CO2 at normal body temp? how do you calculate it?

Back 25

0.063 ml CO2/100ml/toor
0.003 x 21=0.063
multiple by 21 b/c CO2 is 21 times more soluble than O2

Front 26

How do you calculate the amt of CO2 dissolved in plasma of venous blood? arterial?

Back 26

CO2 sol coeff x PCO2
v: 0.063 x 45=2.84mlCO2/100
a:0.063 x 40=2.52mlCO2/100

Front 27

how do you calculate the amt of CO2 released into the alveoli in the dissolved state?

Back 27

subtract amt in arterial bld from the amt in venous bld=
2.84ml-2.52ml=0.32 ml CO2/100mls blood is released into alveoli from pulm caps

Front 28

what is the percentage of CO2 is the dissolved state that is released into the alveoli?

Back 28

total of 4 mls of CO2 are released into alveoli.
0.32/4=8%, but he wants us to know 5-10%

Front 29

which two mechanisms of transport of CO2 by plasma are the least significant?

Back 29

transport as carbonic acid
transport as bicarb ions formed in the plasma

Front 30

does the formation of carbonic acid in the plasma occur rapidly?

Back 30

no, b/c there is no carbonic anhydrase present.
So, only a small amt forms and is transported from tissues to lungs

Front 31

what will happen to some of the carbonic acid that was formed in the plasma?

Back 31

-will dissociate into H+ and HCO3 ions
-CO2 will be transported by the bicarb formed in plasma
-very small amt, even smaller than the amt of carbonic acid formed in plasma

Front 32

how are carbamino cmps formed?

Back 32

when CO2 binds to terminal amine (amino acid residue) on the plasma protein.
(very small amts)

Front 33

why do we have a lower pH in mixed venous blood?

Back 33

due to incomplete buffering of H+ ions produced when CO2 binds to plasma proteins and produces carbamino cmpds

Front 34

3 forms of transport of CO2 by RBC

Back 34

-physically dissolved in fluid of the RBC
-in combination w/ Hgb
-via the formation of HCO3 ions that are formed in the RBC that will be transported as dissolved CO2 in plasma

Front 35

is CO2 physically dissolved in the fluid of the RBC significant?

Back 35

no

Front 36

describe the sequence of events for CO2 to enter the RBC

Back 36

-CO2 diffuses into plasma (40) from tissues (45) d/t PG
-CO2 tension of plasma rises, RBC tension is still 40 b/c it came from arterial side.
-PG develops b/t plasma and RBC, CO2 moves in RBC and dissolves by the time it leaves systemic capillary
-resulting in PCO2 of 45 for both plasma and fluid of RBC

Front 37

PCO2 at the tissue level ranges from ?

Back 37

45-48 torr

Front 38

PCO2 tensions as blood reaches pulm arteriole are:

Back 38

both 45 torr

Front 39

describe sequence of events for CO2 to leave RBC at the alveoli

Back 39

-PCO2 of RBC & plasma are 45 and PACO2 is 40
-PG forms b/t RBC and plasma, CO2 starts moving out of RBC into plasma
-plasma PCO2 levels rise, creating PG b/t plasma and alveoli
-CO2 leaves out of pulm cap into alveoli and bloowwwwwsss away

Front 40

which is more plentiful, carbaminohgb or carbamino cmpds? why?

Back 40

carbaminohgb b/c there is 4x's more Hgb in RBC than plasma proteins in the plasma

Front 41

CO2 binding with the terminal amine/aa residue on the globin portion of the Hgb molecule results in ?

Back 41

formation of a carbaminohgb

Front 42

what is responsible for 5-10% of CO2 transported from tissues to lungs?

Back 42

carbamino cmpds, majority is from carbaminohgb

Front 43

where does O2 and CO2 bind on the Hgb molecule? how does this affect each others binding?

Back 43

O2-ferrous iron site of heme grps
CO2-terminal amine of globin portion
effect: bind of each gas, inhibits the others ability to bind to Hgb

Front 44

What describes oxygen transport at tissue level?

Back 44

Bohr effect

Front 45

Describe Bohr effect

Back 45

-bld passes thru systemic capillaries
-becomes high in CO2
-CO2 binds to Hgb
-decreases Hgb's affinity for oxygen
-Oxygen is released from Hgb and made available to tissues

Front 46

what describes CO2 transport at the lungs?

Back 46

Haldane effect

Front 47

describe haldane effect

Back 47

-bld flows thru pulm capillary
-becomes high in O2
-favors the binding of O2 to Hgb
-decreases Hgb's affinity for CO2
-CO2 releaseed and diffuses into alveoli and blown off

Front 48

major mechanism in which CO2 is transported from tissue to lungs?

Back 48

Via the formation of bicarb ions that are formed in RBC that will be transported into the plasma

Front 49

where is the formation of carbonic acid rapid?

Back 49

in the rbc, d/t carbonic anhydrase being present.
it is formed 13000 times faster in RBC than in plasma

Front 50

in the RBC, when the carbonic acid dissociates, most of the H+ ions are buffered by?

Back 50

deoxygenated hemoglobin

Front 51

describe how bicarb fromed in the RBC, is transported in the plasma

Back 51

-CO2 diffuses from tissues into the plasma
-diffuses into RBC
-here it combines w/ H2O to form carbonic acid
-carbonic acid dissociates into H+ and HCO3 ions
-most H+ are buffered and HCO3 ions build up
-PG exists b/t RBC and plasma and HCO3 starts to leave out to go to lungs

Front 52

what accts for 80-90% of CO2 transported from tissues to lungs?

Back 52

bicarb formed in RBCs and transported in plasma

Front 53

after HCO3 amt builds up and leaves RBC, what occurs?

Back 53

inside of cell has lost his negative particles, so a Cl- ion moves into cell to maintain neutrality

Front 54

movement of Cl- into the cell by a Cl-/HCO3 countertransporter after depletion of HCO3 is termed?

Back 54

Chloride Shift (hamburger interchange/shift)

Front 55

during the chloride shift, H+, HCO3, and Cl is being added to RBC. What occurs as a result of this?

Back 55

RBC's are actually gaining OAS's, water is drawn in to dilute osmolarity back to 300
-at tissue level/venous blood, the RBC's start to swell as a result

Front 56

is there a difference in the number of RBC's present in arterial and venous bld?

Back 56

no, the Hct of venous bld will be higher than arterial bld when spun down d/t the increased volume of packed cells at bottom

Front 57

when bld returns from tissue capillaries to pulm caps, does HCO3 simply move back into RBC?

Back 57

no, there is no conc gradient and it can't go a/g gradient

Front 58

describe movement of CO2 as blood returns from tissue capillaires to pulm capillaries

Back 58

-CO2 diffuses out of plasma (45) into alveoli (40) d/t PG
-This causes PG b/t RBC and plasma (<45)
-CO2 diffuses out of RBC into plasma, causing a shift to the left

Front 59

what states that for a reversible rxn the direction depends on whether we have more substrate or product?

Back 59

Law of Mass action (LeChatelier's Principle)

Front 60

what shows relationship b/t CO2 tension of blood and CO2 content of blood in terms of volume percent?

Back 60

carbon dioxide dissociation curve

Front 61

3 sources of CO2 content

Back 61

-bicarb ions dissolved in plasma (80-90%)
-carbamino cmpds (5-10%)
-CO2 dissolved in plasma (5-10%)

Front 62

1st physical characteristic of carbon dioxide dissociation curve

Back 62

shape is more linear as opposed to sigmoid shape of oxyhgb dissociation curve

Front 63

what affects position of CO2 dissociation curve?

Back 63

affected by oxygen tension of bld

Front 64

what expresses the relationship b/t oxygen and hgb's affinity for CO2?

Back 64

haldane effect

Front 65

what occurs at both the lung and tissue levels?

Back 65

haldane and bohr effect

Front 66

describe haldane effect occurring at the level of the lungs

Back 66

pulm capillaries are picking up oxygen, this decreases Hgb's affinity for CO2, causing greater unloading of CO2, decreasing CO2 content of the bld..shifting curve to the right

Front 67

describe haldane effect occurring at level of the tissues

Back 67

systemic capillaries are getting rid of O2, increasing Hgb's affinity for CO2, Hgb picks up additional Co2, increasing Co2 content of bld, shifting curve to left

Front 68

Haldane effect makes unloading CO2 possible at the ______, and facilitates loading of CO2 at the ________

Back 68

lung, tissue

Front 69

quantitatively, which is more important? Haldane or Bohr?

Back 69

Haldane is more quan imp in transport of CO2 than Bohr is w/ transport of O2

Front 70

the haldane effect accounts for how much additional CO2 transported to alveoli?

Back 70

2, this is half of the amt of total CO2 transported to lungs, it doubles amt of CO2 transported to lungs!

Front 71

if the Bohr effect were not present, increased CO2 did not decrease Hgb's affinity for O2 and shift oxydissociation curve to right, what would happen?

Back 71

venous bld would only have 16 volumes %, so only 4 mls would be given up at the tissues/100mls blood

Front 72

Bohr affect accounts for how much additional Oxygen given to the tissues?

Back 72

1 ml of O2, this is 1/5 of total amt of O2 released (20%) as opposed Haldane's effect of 50%

Front 73

2nd physical characteristic of the CO2 dissociation curve?

Back 73

it is much steeper than the oxyhgb curve

Front 74

ramification of CO2 curve being steeper than oxyhgb diss curve?

Back 74

for any given change in oxygen or CO2, there is greater change in CO2 content and lesser change in O2 content

Front 75

what is the ratio of CO2 output to O2 uptake by the lungs?

Back 75

Respiratory exchange ratio

Front 76

Normal resp exchange ratio:
calculate it!

Back 76

CO2 output/O2 uptake
200ml/min/250ml/min=0.8 if pt is eating a balanced diet

Front 77

resp exchange ratio varies depending upon ?

Back 77

metabolic activity in the body

Front 78

resp exchange ratio if consuming 100% carbs

Back 78

1.0
-for every molecule O2 consumed, 1 molecule of CO2 produced

Front 79

resp exchange ratio if consuming 100% fats

Back 79

0.7, will take more than 1 O2 molecule to give us 1 molecule of CO2

Front 80

ratio of CO2 production to O2 consumption, occurring at level of tissues is termed?

Back 80

respiratory quotient

Front 81

normal resp quotient, how do you calculate?

Back 81

CO2 production/O2 consumption
200ml/min/250ml/min=0.8

Front 82

under steady-state conditions, what should your resp exchange ratio and resp quotient be in comparison w/ each other?

Back 82

should be the same