Lec 36 Ox Transport and Delivery Flashcards
What percent of O2 in blood is dissolved free in solution?
2% of total O2
What is henry’s law?
Cx = Px * Solubility
What is solubility of O2?
0.0003 mL O2/100 mL blood / mmHg
What is conc of dissolved O2 when arterial PO2 is 100 mmHg?
0.3 mL O2/ 100 mL blood
What is O2 consumption of a person at rest?
250 mL O2/min
True or false: O2 deliver base on dissolved O2 alone is sufficient to meet tissue demands
false: dissolved O2 alone is too low/insufficient
What are the forms of O2 in blood?
2% free dissolved
98% bound to HbA
How much of O2 in blood is bound to HbA?
98%
How many O2 bind each HbA?
- each molec HbA has 4 subunits [2 a and 2 B]
- each subunit binds one molec O2
- each Hb binds 4 molec O2
How many mL O2 can 1 gm of HbA bind when 100% saturated?
1.34 mL O2
What is normal Hb concentration of blood?
15 gm/dL
What is normal O2 binding capacity of blood?
15 gm/dL * 1.34 mL = 20.1 mL O2/100 mL blood
What is O2 content of blood?
O2 content = actual amt O2 in mL/100 mL bood
= O2 bound to HbA + dissolved O2
What is equation for O2 bound to HbA?
O2 bound to HbA = O2 binding capacity * percent saturation
What is equation for O2 binding capacity?
O2 binding capacity = Hb conc * 1.34 mL O2/gm Hb at 100% saturation
What is the equation for O2 delivery to tissues?
O2 delivery = blood flow * O2 content of blood
in more detail:
O2 delivery = CO [Q] * (Oxygenated Hb + dissolved O2)
Is O2 binding Hb reversible or irreversible?
reversible
Is relationship of % saturation Hb and PO2 in arteries linear?
no - its nonlinear
What is P50?
PO2 at which Hb is 50% saturated
What is positive cooperativity?
change in affinity of heme groups for O2 as each successive O2 molecule binds = steep part of Hb-O2 dissociation curve
Where is Hb loading of O2?
into pulmonary capillaries from alveolar gas
Where is Hb unloading of O2?
from systemic capillaries into tissues
How saturated is Hb in systemic venous capillaries?
75% saturated
How saturated is Hb in alveolar arterial capillaries?
97.5% saturated = basically 100%