Oxygen and CO2 Transport Flashcards

0
Q

O2 Content

A

Dissolved O2 + 1.34(Hb)(Hb-O2)

Expressed as a volume percent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Henry’s Law

A

Amount of gas in a fluid depends on partial pressures

  • Means that gases move thru fluids by following their pressure gradient
  • Once combined w/ a molecule, like Hb, they no longer exhibit a partial pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Arterial Blood Saturation

A

97.4%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Venous blood O2 saturation

A

75%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Oxygen diffusion constant

A

.003/PatmO2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Affects of HbCO

A
  1. Reduces # of sites available for O2
  2. Increases the affinity for already bound O2
    - less release of O2 at tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

CO-poisoning

A

Decreased levels of tissue O2 leading to anemia

Symptoms include: Cherry-red appearance
Dizziness
Confusion

  • Lethal amount=0.6mmHg
  • Treatment=95%O2/5%CO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

O2 Capacity

A

Maximal amount of O2 Hb is capable of carrying; DOES NOT include dissolved O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hb Saturation

A

(HbO2/O2 capable of binding) X 100

or

(O2 content- O2 dissolved/ O2 capacity) X 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pulse oximeter

A

Compares photon reflectance of 2 different wavelengths of light to determine Hb/HbO2 ratio

650nm (red)- HbO2 reflects; Hb absorbs

900nm(infrared)- HbO2 absorbs; Hb reflects

*Not affected by concentrations or skin color because a ratio is measured

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pulse oximeter issues

A

Cannot tell you [Hb] and what Hb is saturated with (could be CO)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hypercapnia

A

Increased CO2 leads to respiratory acidosis

-Shortness of breath, confusion, fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hyperventilation

A

Can lead to respiratory alkalosis

-Dizziness, light-headedness, numbness of hands/feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Normal P50

A

About 26 mmHg

*Increased P50 => Hb-saturation curve shifts to right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

DPG in stored blood

A

Can degrade; leads to increased O2 affinity of Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Polycythemia

A

A result of chronic hypoxia; results in an increased Hcrt but also increased viscosity and work load on the heart

16
Q

Transportation mechanisms of CO2

A
  1. Dissolved in blood
    - diffuses 20x more rapidly than O2
  2. Bicarbonate buffer system
    - CO2 moves into RBCs and is converted to H2CO3 by carbonic anhydrase; H+ is added to Hb and HCO3- exits into the plasma and Cl- enters
    * Opposite @ the lung capillaries
  3. Carbamino compounds
    • Binds to Hb; high affinity to deoxyhemoglobin found primarily in the tissues
17
Q

Mixing blood samples w/ 2 different PCO2s

A

Average the PCO2s of the samples

-Can do this due to the fact that the curve is linear and shows no saturation

18
Q

Mixing Blood Samples w/ 2 different PO2s

A

Must average the O2 content of the samples and then find the corresponding PO2; occurs due to non-linear relationship of curve

*Lungs are continually doing this since different regions have different PO2s

19
Q

Non-Respiratory Functions of the Lung

A

Defense Mechanism: Macrophages phagocytize foreign particles and secrete activator substances for other WBCs

Air Condition: Nasal concha warm and humidify inspired air

Olfactory: Shmolfactory

Filtration: Performed by mucous lined, ciliated pseudostratified columnar epithelia; smoking decreases function of mucociliatory escalator

Blood Filter: can filter out harmful objects, like emboli, and store them in the pulmonary capillaries

Blood Reservoir: contains reserves of blood for left ventricle in times of increased stress

Metabolism of circulating substances: performed by the endothelial cells

20
Q

Bronchiectasis

A

Scarring of the airways due to recurrent infection/inflammation; can be caused by a damaged muscociliatory escalator

*Could also happen to incubated pts. since they have decreased coughing capabilities; foreign substance must be removed by suction

21
Q

Thiazide diuretics

A

Contribute to H+ loss and Ca2+ reabsorption