Question

Breathing 100% oxygen will:

A. Increase p02 and the rate of oxygen unloading at the tissues.

B. Cause a right shift in the oxygen-hemoglobin dissociation curve.

C. Significantly increase oxyhemoglobin saturation.

2. All of the following play a role in increasing the oxygen unloading at tissue in someone with iron deficiency anemia except?

A. Respiratory acidosis

B. An increase in 2-3 DPG

C. An increase in deoxyhemoglobin

D. The affinity of 2-3 DPG for hemoglobin

Answer 1

1.Our blood has evolved to capture the oxygen we breathe in and bind it safely to the transport molecule called haemoglobin. If you breathe air with a much higher than normal O2 concentration, the oxygen in the lungs overwhelms the blood's ability to carry it away.

The result is that free oxygen binds to the surface proteins of the lungs, interferes with the operation of the central nervous system and also attacks the retina.

Breathing 100% oxygen also eventually leads to collapse of the alveoli (atelectasis), while—at the same partial pressure of oxygen—the presence of significant partial pressures of inert gases, typically nitrogen, will prevent this effect.

So option C, significantly increases oxyhaemoglobin saturation is the correct answer.

2. The blood hemoglobin concentration is determinant of oxygen delivery. In anemic patients, oxygen delivery decreases and oxygen extraction is increased. This leads to decreased venous hemoglobin saturation and a lower tissue oxygen saturation.

The blood hemoglobin concentration is determinant of oxygen delivery. In anemic patients,oxygen delivery decreases and oxygen extraction is increased. This leads to decreased venous hemoglobin saturation and a lower tissue oxygen saturation. The rate of tissue deoxygenation during ischemia is dependent on oxygen consumption and on the amount of oxygen available in the tissue.

C. Increase in deoxyhaemoglobin doesnt induce oxygen delivery at tissues.

Rest all options increases oxygen delivery at tissues.