Breathing and exchange of gasses

Question

In carbon monoxide (CO) poisoning, CO

binds to the heme of hemoglobin much

easier than oxygen. What effect will this

have on the ability of the tissues to get

oxygen?

1. More carbonic acid will be produced,

and the hemoglobin will give up more

oxygen to the tissue.

2. Hemoglobin will bind to less oxygen,

and hemoglobin will not release as

much oxygen to the tissue.

3. Carbon monoxide makes hemoglobin

give up oxygen more readily in the

tissues.

4. Carbon monoxide ties up hemoglobin's

ability to bind to oxygen, but more

hemoglobin will be produced, so no

decline in oxygen in the tissue will be

noticed.

Answer 1

The answer here is B. Since CO binds to hemoglobin with an affinity about 100x that of oxygen, CO will bind more readily to hemoglobin, making less hemoglobin sites available for binding and oxygen delivery to tissue. In chronic cyanosis, the body will produce more hemoglobin, but this takes time, and CO poisoning is an acute process.