O2 Transport

Question 1

Define Cooperative Binding

Answer 1

Hb affinity for O2 increases as its saturation increases

Question 2

what alters PO2?

Answer 2

pH
temperature change
PCO2
2,3 DPG

Question 3

what shift of the curve increases O2 unloading?

Answer 3

right shift (bohr effect)

Question 4

what shift of the curve decreases O2 unloading?

Answer 4

Left

Question 5

why is there a big drop in pressure as O2 enters the body

Answer 5

O2 gets diluted because of the exchange of O2 coming in and out of body

Question 6

Blood perfusing the lungs is….

Answer 6

gravity dependent

bases are better perfused than apices

Question 7

explain starling effect

Answer 7

amount of blood returned to the heart (preload) determines the amount ejected

Question 8

what are some threats to O2 transport in regards to control of breathing?

Answer 8

altered CNS afferent Input
impaired efferent pathways
pharmacological and substance-abuse depression

Question 9

what are some threats to O2 transport in regards to airways?

Answer 9

aspiration
obstruction secondary to airway edema, bronchospasm or mucus
inhaled foreign bodies

Question 10

what are some threats to O2 transport in regards to airways ?

Answer 10

ineffective breathing pattern
ineffective airway clearance
chest wall abnormalities
impaired lung fluid balance and acute lung injury

Question 11

what are some threats to O2 transport in regards to blood?

Answer 11

bleeding abnormalities 
low hematocrit secondary to GI bleed 
anemia 
thrombocytopenia 
disseminated intravascular coagulation 
thromboemboli

Question 12

what are some threats to O2 transport in regards to gas exchange?

Answer 12

intrapulmonary shunt 
pulmonary edema 
V/Q mismatch 
diffusion defects 
alveolar collapse 
atelectasis 
body position

Question 13

what are some threats to O2 transport in regards to respiratory muscles?

Answer 13

weakness 
fatigue 
neuromuscular disease 
upper abdominal surgery 
intestinal obstruction

Question 14

what are some threats to O2 transport in regards to heart?

Answer 14

decreased venous return and CO 
conduction defects 
mechanical defects 
abnormal distension and myocardial wall compliance 
abnormal afterload

Question 15

what are some threats to O2 transport in regards to systemic Hemodynamics?

Answer 15

blood pressure
volume deficit
volume excess

Question 16

what are some threats to O2 transport in regards to tissue perfusion ?

Answer 16

impaired CO
atherosclerosis
thromboembolism
low O2 content in the blood

Question 17

does the respiratory system limit exercise?

Answer 17

not in healthy untrained (over built)

in highly trained athletes it may limit because it does not adapt

Question 18

how is EIAH characterized?

Answer 18

decrease in PaO2 and an increase in alveolar-to-arterial O2 difference

Question 19

what could possibly cause EIAH?

Answer 19

inadequate hyper ventilatory compensation
ventilation/perfusion mismatching
arterio-venous shunting
pulmonary diffusion limitation
respiratory muscle fatigue and steal of skeletal muscle blood flow

Question 20

define alveolar hypoventilation

Answer 20

alveolar ventilation below the rate metabolically required to maintain blood gases at normal levels
PaCo2>35mmhg

Question 21

define extra pulmonary shut

Answer 21

deoxygenated blood returning from exercising muscles bypasses the lungs completely

Question 22

define intrapulmonary shunt

Answer 22

deoxygenated blood that passes through the lungs but does not participate in gas exchange mixes with arterial blood and dilutes it

Question 23

what are the 2 major determinants for alveolar capillary diffusion during exercise?

Answer 23

decreased transit time of RBC in the pulmonary capillary

increased distance for diffusion

Question 24

what is the diffusion limitation functions of the Blood-gas barrier

Answer 24

must be able to perform pulmonary gas diffusion (thin walls)
but be able to withstand high capillary wall stresses with exercise so must be strong