Gas Transoort In The Blood

Question 1

How does Hb affect O2 transport?

Answer 1

Blood carries >40x the amount of O2 that would be carried by just plasma due to Hb

Question 2

Most O2,_______, is transported by binding with hemoglobin

Answer 2

98.5%

Question 3

Hb molecule

Answer 3

4 heme and 4 goblin
2alpha and 2 beta goblin chains (fetal Hb has gamma)

Question 4

How do RBC generate energy?

Answer 4

Anaerobically
No organelles so can’t use the O2 they carry

Question 5

Oxyhemoglobin

Answer 5

O2-Hb combination

Question 6

Reduced Hb or deoxyHb

Answer 6

Hb that has released O2

Question 7

Oxyhemoglobin dissociation curve

Answer 7

Affinity of a heme group is influenced by the oxygenation of the other
Results in the Sigmoid shape of curve
Displays percent saturation of Hb as a function of O2 tension

Question 8

Oxygen capacity

Answer 8

Maximal amount of O2 that can be carried in blood at any given time
1 g of saturated Hb holds 1.34 ml of O2

Question 9

Oxygen content

Answer 9

Amount of oxygen in blood at any time

Question 10

SaO2

Answer 10

Arterial O2 saturation of Hb

Question 11

SvO2

Answer 11

Mixed venous O2 saturation

Question 12

What factors affect O2 content/ capacity

Answer 12

Anemia
Polycythemia

Question 13

Anemia

Answer 13

Decreasing RBC, Hb and capacity
Hemolytic disease, blood sucking parsites
Deficiencies (iron)

Question 14

Polycythemia

Answer 14

Increasing RBC, Hb and capacity
Exercise (contraction of spleen)
Blood doping

Question 15

Oxyhemoglobin dissociation curve smaller vs larger animals

Answer 15

Small animals: higher PO2 needed to saturate 50% of Hb and unload O2
Curve shifts right for smaller animals (reduced affinity of Hb for O2)

Question 16

What will shift the O2-Hb curve to the right?

Answer 16

Reduced affinity
Metabolism produces heat
Acids
BPG

Question 17

What will shift the O2-Hb curve to the left?

Answer 17

Increased affinity
Hypothermia
Alkaline
CO

Question 18

Oxygen- saturated Hb

Answer 18

Bright-red
Becomes purplish (bluish red) as it loses oxygen (cyanosis)

Question 19

Cyanosis

Answer 19

Due to deficient O2 uptake (inspired, diffusion)
Reduced blood flow to tissues (cardiovascular failure)

Question 20

Carbon monoxide (CO) poisoning

Answer 20

Produced by incomplete combustion of carbon-containing materials

Question 21

Nitrite poisoning

Answer 21

Nitrites oxidize ferrous ion to ferric iron forming Methemoglobin (methemoglobinemia)
Corrected by MetHb reductase of RBC or therapy

Question 22

What is the source of nitrites?

Answer 22

Spoiled feed
Nitrate-rich feeds in ruminants
Fertilizers

Question 23

What are the forms of CO2 transport

Answer 23

In plasma: Disolved CO2- 10%
In RBC:
Bicarbonate - 69%
Carbamino compounds - 21%
Carbonic acid (H2CO3)
Carbonate (CO32-)**- significant

Question 24

What does an increase in CO2 cause?

Answer 24

A negative effect on O2 bonding
Most deoxygenated blood carries more CO2 (higher buffering capacity)

Question 25

How is O2 demand met during exercise?

Answer 25

Increasing blood flow
Hb levels
O2 extraction from blood
Myoglobin released O2 when PO2 is low

Question 26

Myoglobin

Answer 26

Oxygen binding and storage pigment in muscle
More abundant in slow-twitch aerobic muscles than in fast-twitch muscles
Releases O2 only when PO2 is low
Increased by training