Respiratory System- Practice Quiz

A dry gas mixture at 760 mm Hg pressure contains 21% oxygen.
The PO2 of this gas mixture is

 

160

Which of the following statements about the bond between hemoglobin and oxygen is true?

 

The bond is weakened under acidotic conditions.

Respiration is the mechanical process that moves air into and out of the lungs.

F

Gas exchange can occur anywhere along the conducting passageways of the respiratory system.

F

Boyle's law states that, for a given quantity of gas, the

 

pressure is inversely proportional to volume

Inspiration occurs when the intrapulmonary (alveolar) pressure is greater than atmospheric pressure outside the body.

F

The PO2 of the blood is

 

none of these is correct

Most of the carbon dioxide in blood is ultimately dissolved in the plasma, leaving a lesser amount in the red blood cells.

T

Pulmonary arteriolar smooth muscle constricts when alveolar PO2 is low, sending blood away from alveoli that are poorly ventilated.

T

Peripheral chemoreceptors ae highly sensitive to changes in blood oxygen content.

F

A shift in the oxyhemoglobin dissociation curve to the left indicates a greater oxygen unloading from hemoglobin.

F

The oxyhemoglobin dissociation curve shifts to the right when hemoglobin experiences a

 

all of these are correct

Aerobic cellular respiration consumes oxygen, lowering venous blood PO2 to about 40 mm Hg and percent saturation to 75%.

T

The chloride shift in the tissues involves the diffusion of Cl- out of the red blood cells as bicarbonate ion diffuses into them.

F

Which statement about the respiratory rhythmicity center of the brain stem is false?

 

It controls pulmonary ventilation voluntarily