O2 & CO2 transfer between alveolus, Blood&tissue

Question 1

how does gas move through the conducting airways

Answer 1

by Convection

Question 2

how does gas is exchanged across the Blood-Gas barrier in the Alveolus

Answer 2

by diffusion

Question 3

2 forms of O2 that can be transported in blood

Answer 3

physical and chemical

Question 4

physical form of O2

Answer 4

is plasma soluble O2 (2%)

• less soluble than CO2
• function of partial pressure of O2 in alveolus
• 0.3ml O2/100ml blood at PO2 of 100mmHg (normoxic alveolar PO2)

Question 5

chemical form of O2

Answer 5

O2 bound to haemoglobin (98%)

• rapid and reversible interaction
• reversibility enable O2 off-loading to tissues
• Hb (Deoxyhemoglobin) +O2 HbO2 (Oxyhemoglobin)

Question 6

how much O2 is carried by Haemoglobin?

Answer 6

1g Hb binds 1.34ml O2
15g Hb/100ml total blood
=>Hb carrying capacity = 1.34 x 15=20mlO2/100ml

Question 7

total arterial Blood Oxygen content (CaO2)

Answer 7

O2 carrying capacity of Hb + Plasma soluble O2
20mlO2/100ml + 0.3mlO2/100ml
=20.3 mlO2/100ml total blood

Question 8

total venous Blood Oxygen (CvO2)

Answer 8

O2 carrying capacity of Hb + plasma soluble O2
= 15mlO2/100ml + 0.28 mlO2/100ml
= 15.28mlO2/100ml total blood

Question 9

tissue O2 uptake

Answer 9

you can find it by substracting the total O2 venous content from the O2 arterial blood content
=20.3-15.28=5.02 mlO2/100ml total blood