Respiratory Gases and Necessity for Breathing Flashcards Preview

Tri 4 - Cardio Resp > Respiratory Gases and Necessity for Breathing > Flashcards

Flashcards in Respiratory Gases and Necessity for Breathing Deck (62)
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1
Q

what are the two respiratory gases associated with cellular metabolism?

A

O2

CO2

2
Q

CO2 reacts with H2O to produce

A

carbonic acid

3
Q

accumulation of CO2 casues increased

A

acidity

4
Q

what is the process called of oxidation of fuels to generate ATP and heat

A

cellular respiration

5
Q

_____ transport is via pulmonary venous return to the left heart and cardiac output from the left heart to the tissues

A

oxygen

6
Q

______ transport is via systemic venous return to the right heart and cardiac output from the right heart to the lungs

A

carbon dioxide

7
Q

the quantity of the respiratory gases within the blood are expressed in terms of both ____ and ____

A

content

partial pressure

8
Q

the concentration (quantity per volume) of respiratory gases within the blood (volume %)

A

content

9
Q

reflective of the quantity of O2 or CO2 dissolved within plasma expressed as either mm Hg or cm H2O (units of pressure)

A

partial pressure

10
Q

PO2

A

partial pressure of oxygen

11
Q

PCO2

A

partial pressure of carbon dioxide

12
Q

the dissolved concentration is dependent upon the partial pressure, in conjunction with the solubility of the gas within the liquid (solubility is a physical constant)

A

henry’s law

13
Q
A

Henry’s Law

14
Q

Cellular metabolism generates a continual tendency to

  1. ____ O2 from the surrounding interstitial fluid (___ the PO2)
  2. _____ CO2 into the interstitial fluid (___ the PCO2)
A

deplete O2

Load CO2

15
Q

PO2 of the blood ___ PO2 of the interstitial fluid

A

>

16
Q

PCO2 of the interstitial fluid ___ PCO2 of the blood

A

>

17
Q

the diffusion ___ results from the partial pressure of the dissolved molecules

A

diffusion force

18
Q

the diffusion ____ is the difference in partial pressure between blood entering the capillary and the interstitial fluid

A

diffusion gradient

19
Q

increased metabolism : _____ O2 in venous blood

A

decreased

20
Q

what establishes the diffusion gradient that draws O2 out of the blood

A

metabolic consumption of O2

21
Q

what is the partial pressure of CO2 in the blood from tissues

A

40mmHg

22
Q

what establishes the diffusion gradient that drives CO2 into the blood

A

metabolic production of CO2

23
Q

increased metabolism: ____ CO2 in venous blood

A

increased

24
Q

what establishes a dynamic disequilibrium (in terms of PO2 and PCO2) between the interstitial fluid and the systemic arterial blood flowing into the tissues

A

cellular metabolism

25
Q

(arterial blood -> systemic capillaries) the O2 content of the tissues is ____;

O2 diffuses from ____ into the ____

A

lower

blood into the tissues

26
Q

(arterial blood -> systemic cpaillaries) the CO2 content of the tissues is _____;

CO2 diffuses from ___ into ___

A

greater;

tissues into blood

27
Q

increased metabolism causes:

______ of O2 from systemic arterial blood

_____ of CO2 into systemic venous blood

A

removal of a greater quantity of O2 from systemic arterial blood

addition of a greater quantity of CO2 into systemic venous blood

28
Q

metabolism has NO change in ________

A

systemic arterial blood

29
Q

metabolism has a direct affect with _______ of respiratory gases

A

systemic venous

30
Q

the PCO2 of alveolar gas is ___

A

PCO2;

CO2 diffuses from the blood into alveolar gas

31
Q

the PO2 of alveolar gas is _____

A

higher;

O2 diffuses from alveolar gas into the blood

32
Q

increased metabolism: alveolar gas __ PO2, __ PCO2

A

increased PO2

decreased PCO2

33
Q

____ gas

  • provides a readily available reserve of molecular O2 for distribution to the tissues
  • receives and holds for subsequent excretion excess CO2 arising from tissue metabolism
A

alveolar

34
Q

what determins the PO2 and PCO2 of the systemic venous blood returning to the lungs

A

overall rate of metabolism

35
Q

what depends upon the magnitude of the diffusion gradients between blood perfusing the alveoli and the alveolar gas

A

rates of pulmonary diffusive exchange

36
Q

why must we breathe

A
  • remove excess CO2 generated by tissue metabolism that is loaded into the alveolar gas
  • replenish O2 within the alveolar gas relative to the amount that is loaded into the blood for transport to the tissues of cellular metabolism
37
Q

metabolism rate controls ______ rate

A

breathing

38
Q

what serves as the most immediate reserve to buffer the interstitial respiratory gas levels

A

blood

39
Q

imediately accessible reserve of available O2 for the tissues

A

systemic arterial blood

40
Q

absorbs (buffers) excess CO2 from the tissues

A

systemic venous blood

41
Q

__ is insoluble in the plasma, ___ is 20x more soluble in the plasma

A

O2 insoluble

CO2 20x soluble

42
Q

what is a single carries molecule for O2

A

hemoglobin (Hb)

43
Q

CO2 also binds to __ and ___ in the blood as carrier molecules

A

Hb

HCO3-

44
Q

CO2 dissolved in plasma is known as

A

carbonic acid and bicarbonate ion

45
Q

CO2 bound to proteins in the blood

A

binds to amino groups on Hb

binds to other plasma proteins

46
Q

the capability of Hb to bind CO2 is dependent upon the PO2

A

Haldane effect

47
Q

decreased PO2: ___ capacity of Hb to carry CO2

A

increased;

deoxyhemoglobin has a higher affinity for CO2

48
Q

increased PO2: ____ capacity of Hb to carry CO2

A

decreased;

as O2 bind to Hb, its affinity to bind CO2 lessens

49
Q

CO2 retention (increased PCO2): ___ pH

A

decreasing pH

50
Q

CO2 excretion (decreased PCO2): ___ pH

A

increasing pH

51
Q

what largely determines the capacity to load O2 into the blood

A

how much hemoglobin there is in the blood (Hb concentration)

52
Q

what expresses what percentage of the capacity provided by hemoglobin to bind O2 is currently used up

A

Hb saturation

53
Q

the average PO2 of blood leaving the lungs is

A

95mm Hg

  • Hb almost 100% saturated with O2
  • plateau region: O2 Hb binding is relatively insenstive to small changes in the PO2
54
Q

the average PO2 of blood leaving the tissues is

A

40mm Hg;

  • Hb is still 70% saturated with O2
  • steep region: O2 Hb binding is highly sensitive to small changes in the PO2
55
Q

the likelihood of O2 binding to hemoglobin is known as

A

affinity

56
Q

what causes a change in sensitivity of affinity of Hb for O2

(graph)

A

carbon monoxide causes leftward shift: increased affinity

increased metabolism causes rightward shift: reduced affinity

57
Q

how many molecules of hemoglobin are present within a unit of volume of blood - this represents the capacity to load CO2 inot that unit volume (size of the container of O2)

A

Hb concentration

58
Q

percent saturation with O2, which measures how much the capacity is utilized (how full the container is with O2)

A

affinity and PO2

59
Q
  • given Hb concentration and affinity-

the O2 content depends upon the ___ of the blood

A

PO2

60
Q
  • give PO2 -

the O2 content depends upon the ____

A

Hb concentration

61
Q

increased Hb concentration: ___ O2 content

A

increased

62
Q

changes in the Hb concentration will change the ____, but will NOT change the ____ or ____

A

will change - O2 content

will NOT change - percent saturation, nor PO2 of the blood