Exam 27: A: Physiology of the Respiratory System

The formation of carbaminohemoglobin is a reversible reaction.

Carbonic acid forms when carbon dioxide reacts with water in the blood plasma.

Hemoglobin is a quaternary protein consisting of four tertiary polypeptide chains.

The partial pressure of oxygen in the alveolar air is equal to the partial pressure of oxygen in the systemic venous blood.

In the lung,as the partial pressure of oxygen of the blood goes up,the partial pressure of oxygen in the alveolar air goes down proportionally.

Chemoreceptors can be found in both the carotid bodies and the aorta.

A poorly profused but well ventilated part of the lung wastes blood.

The terms oxygen partial pressure and oxygen tension are interchangeable.

Hemoglobin can carry oxygen more efficiently than it can carry carbon dioxide because all four polypeptide chains can carry oxygen,but only the beta chain can carry carbon dioxide.

In maximum inspiration and expiration,the inspiratory and expiratory reserve volumes would change but the residual volume would remain constant.

An increase in the partial pressure of carbon dioxide decreases the affinity between hemoglobin and oxygen.This is called a "right shift," or the Haldane effect.

A person who is trapped underwater for a long enough time will drown and this indicates that the cerebral cortex does not have complete control of breathing.

A primary function of the respiratory system is to supply tissue with adequate oxygen and to remove carbon dioxide.

Anatomical dead air space and physiological dead air space are interchangeable terms.

With emphysema,the amount of dead space air increases.

The expiratory center of the medulla seems to be inactive in normal,quiet breathing.

The pneumotaxic center operates mainly to prevent overinflation of lung tissue.

Although the respiratory system is responsible for ventilation,the circulatory system is responsible for perfusion.

Hypoventilation is characterized by low levels of carbon dioxide.

An increase in the plasma PCO₂ and a decrease in PO₂ cause an increase in the dissociation of CO₂ from hemoglobin.