Respiratory 4

Question 1

Carbon Monoxide : characteristics

Answer 1

Colorless. Odorless, tasteless, non-irritant has.
Competes for O2 binding sites on Hb
Can kill even in small concentration in air .

Question 2

The affinity of Hb for CO

Answer 2

Is 250 times more than O2

CO+Hb ~ HbCO( Carboxyhemoglobin)

Question 3

Carboxyhemoglobin : it’s role in hypoxia

Answer 3

HbCO cannot carry O2 leading to functional anemia …. anemic hypoxia occurs .
CO occupies O2 binding on Hb= decrease O2 binding capacity O2 Hb and O2 content of blood is decreased .

Question 4

Why is PO2 normal in CO poisoning ?

Answer 4

PO2 is the 3% dissolved O2 in plasma. But that amount is not sufficient to meets tissue oxygenation demand .
But since PO2 is normal : no cyanosis seen.