Ex phys Final Pulmonary Fall24

The term ventilation refers to the

mechanical process of moving air in and out of the lungs

The most important muscle of inspiration is/are the

diaphragm

In the standing position, blood flow to the base of the lung is_________ blood flow to the apex.

greater than

Exercise-induced asthma can impair pulmonary gas exchange by

increasing airway resistance and reducing ventilation to the lung.

Most of the O2 contained in the blood

is bound to hemoglobin as oxyhemoglobin.

Carbon dioxide is transported in arterial blood principally as

bicarbonate ions (HCO3-).

Studies reveal that ventilation drifts upward during constant-load submaximal exercise performed in a hot and humid environment. This is likely due to

an increase in core temperature and the body's demand for greater oxygen intake.

The respiratory control center is located within the

medulla oblongata

The central chemoreceptors that influence the control of breathing respond to changes in the

PCO2 and H+ of cerebral spinal fluid

A decline in arterial PO2 to 70 mm Hg or below would likely result in

an increase in alveolar ventilation

Under normal conditions at sea level, the partial pressure of oxygen in the alveolar region of the lung is aprroximately

100mmgHg

In healthy and untrained subjects, the curvilinear rise in minute ventilation observed during incremental exercise (i.e., ventilatory threshold) could be due to

a decrease in arterial pH

Contraction of the rectus abdominis muscles would result in

active expiration

During very heavy exercise at sea level, young, healthy untrained subjects generally maintain arterial

PCO2 within

30–40 mm Hg of resting values

A significant increase in blood temperature (i.e. from 37°C to 39°C) would result in _________ in the oxyhemoglobin dissociation curve.

a rightward shift

At a low PO2, myoglobin has_________ affinity for O2 than hemoglobin.

a higher

The volume of gas inspired during a breath is defined as

tidal volume.

Diffusion is defined as

random movement of molecules from area of high concentration to an area of lower concentration.

Which of the following statements about sex differences in breathing are correct?

When matched for age and body weight, women have smaller airways compared to men and The energy requirement for breathing during exercise is higher for women compared to men

The carotid bodies are chemoreceptors that are sensitive to changes in arterial_________.

PH, PCO2, and PO2

A ventilation-perfusion (V/Q) ratio of 1.0 would indicate

that ventilation is higher than blood flow in this region of the lung.

A voluntary increase in alveolar ventilation (at rest) resulting in hyperventilation will reduce arterial _________ and increase arterial _________ .

PCO2; PO2

In a healthy individual at rest (sea level conditions), which of following characteristics of arterial blood are correct?

Oxygen content of 20ml O2/100 ml blood

Compared to the oxyhemoglobin dissociation curve, the myoglobin dissociation curve _________.

is much steeper at PO2’s below 20 mmhg

During a graded exercise test, the increase in ventilation during the transition from rest to moderate exercise is achieved by

an increase in both breathing frequency and tidal volume

Which of the following statements are true about the changes in ventilatory patterns (i.e., tidal volumes and breathing frequency) during exercise?

Increasing tidal volume during exercise ensures that dead space ventilation remains small.