5B-GAS transport/perfusion ratios

Question 1

How much oxygen is dissolved in plasma?

Answer 1

1.5% the rest is in hemoglobin!

Question 2

Which state is the iron in for hemoglobin?

Answer 2

FERR-OUS (Fe2+)

Question 3

What is the normal adult hemoglobin sometimes called?

Answer 3

Alpha2Beta2

Question 4

What is the partial pressure of O2 in venous blood? Somewhat confusing to me :) What about arterial blood?

Answer 4

40mmHg veins……100mmHg arteries

Question 5

What percent hemoglobin saturation is happening at 25mmHg?

Answer 5

50% saturation…NO BUENO!

Question 6

What does the flat part of the O2 dissociation curve mean?

Answer 6

O2 is being taken up by heme in the lungs

Question 7

What does the steep part of the O2 dissociation curve mean?

Answer 7

O2 is being dropped off at the tissues

Question 8

What is the concept that the heme gets more attraction to O2 as it picks one up?

Answer 8

Positive Cooperativity

Question 9

What is the ALVEOLUS partial pressure of O2(hint: even HIGHER then arterial P-O2)

Answer 9

104mmHg

Question 10

What is the approximate P-O2 at the myoglobin in the muscle?

Answer 10

23mmHg…Really hungry for O2!

Question 11

What are the four factors that influence hemoglobin saturation?

Answer 11

1.Temp 2.blood pH 3.[CO2] 4.[2,3-B(orD)PG]

Question 12

What is 2,3B(orD)PG a product of?

Answer 12

Glycolysis in the RBC..It binds REVERSIBLY to hemoglobin

Question 13

What does a shift to the RIGHT in the heme dissociation curve indicate?

Answer 13

An O2 affinity decrease (HIGH CO2, LOW pH, HIGH Temp, HIGH 2,3BPG)

Question 14

What is the Bohr effect on Heme saturation? What is the BEST example of when the Bohr effect takes place?

Answer 14

JUST considering HIGH CO2 and LOW pH…DURING EXERCISE!

Question 15

Other then Bohr’s effect, what about exercise is going to cause a Right shift in the heme affinity chart?

Answer 15

Increased Temp!

Question 16

Which chain of heme does 2,3BPG bind to?

Answer 16

the BETA chains!

Question 17

Which of the 4 affinity factors does living at high altitude change?

Answer 17

2,3 BPG goes up at high altitude

Question 18

Overall, what does a shift to the left on the hemoglobin dissociation curve indicate?

Answer 18

MORE AFFINITY for O2!!

Question 19

How much more affinity does heme have for CO compared to O2?

Answer 19

Heme is 200x more attracted to bind CO!!

Question 20

What does the Heme-O2 dissociation curve look like with CO poisoning?

Answer 20

Plateaus big time

Question 21

_______ is a decrease in arterial PO2, whereas _______ is decreased O2 delivery to the tissues.

Answer 21

Hypoxemia………hypoxia

Question 22

Hypoxia can be caused by ______ cardiac output, _____ O2-binding capacity of hemoglobin, or ______ arterial PO2.

Answer 22

decreased……decreased…..decreased

Question 23

________ reflects poor O2 delivery resulting from TOO FEW RBCs or from RBCs that contain abnormal or too little Hb.

Answer 23

Anemic hypoxia

Question 24

_________ results when blood circulation is IMPAIRED or blocked. Congestive heart failure may cause body-wide this, whereas emboli or thrombi block oxygen delivery only to tissues distal to the obstruction.

Answer 24

Ischemic (stagnant) hypoxia

Question 25

_________ occurs when body cells are unable to use O2 even though adequate amounts are delivered. This variety is the consequence of metabolic poisons, such as cyanide.

Answer 25

Histotoxic hypoxia

Question 26

_________ is indicated by reduced ARTERIAL PO2. Possible causes include disordered or abnormal ventilation-perfusion coupling, pulmonary diseases that impair ventilation, and breathing air containing scant amounts of O2.

Answer 26

Hypoxemic hypoxia

Question 27

What are the three ways CO2 is transported in the blood? What are the percentages of each method?

Answer 27

Dissolved-7%……Bound to hemoglobin-23%……BOOM-BICARB-70%-90%

Question 28

Which ion is exchanged with Bicarb to maintain osmotic equilibrium?

Answer 28

Cl-The “Chloride shift” yo!

Question 29

What happens between Chloride and Bicarb at the lungs?

Answer 29

Chloride out of the RBC, Bicarb in then converted to CO2 for exhale!

Question 30

A ______ is the ratio of alveolar ventilation (V) to pulmonary blood flow (Q). Ventilation and perfusion matching is important to achieve the ideal exchange of _____ and ____.

Answer 30

V/Q ratio…..O2…..CO2

Question 31

What is a normal V/Q ratio? What is the normal ventilation? What is the normal blood flow to get this number?

Answer 31

0.8….V=4.2L/min Q=5.5L/min blood flow

Question 32

There are relatively marked differences in this ventilation/perfusion ratio in various parts of the lung as a result of the effect of _____.

Answer 32

gravity!

Question 33

If the ventilation to an alveolus is reduced relative to its perfusion, the pO2 in the alveolus ___ because less O2 is delivered to it and the alveolar pCO2 _____ because less CO2 is expired.

Answer 33

falls…..rises

Question 34

If the airways are completely blocked (e.g., by a piece of food caught in the trachea), then ventilation is zero. If blood flow is normal, then V/Q is zero, which is called a _____. What is the V/Q ratio?

Answer 34

shunt…V/Q=0 (0/5.5)

Question 35

If blood flow to a lung is completely blocked (e.g., by an embolism occluding a pulmonary artery), then blood flow to that lung is zero. If ventilation is normal, then V/Q is infinite, which is called ______. What is the V/Q ratio?

Answer 35

dead space…V/Q= INFINITY!! (4.2/0)