Exercise Physiology Chapter 10 Test Bank - UARK

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.

The volume of gas that reaches the gas-exchange zone of the lung is termed

alveolar ventilation.

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

greater than

Exercise-induced asthma could impair pulmonary gas exchange by

increasing airway resistance.

Most of the O2 contained in the blood

is bound to hemoglobin as oxyhemoglobin.

Carbon dioxide is transported in arterial blood principally as

bicarbonate.

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

a significant increase in body temperature.

The exercise-induced hypoxemia that occurs in elite endurance athletes during heavy exercise is likely due to

a diffusion limitation secondary to a rapid red blood cell transit time.

The respiratory control center is located in 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 alveoli region of the lung is

100 mm Hg.

In healthy and untrained subjects, the a linear 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.

The right shift in the oxyhemoglobin dissociation curve due to a rise in hydrogen ion concentration is called

the Bohr effect.

During exercise at sea level, young, healthy untrained subjects generally maintain exercise arterial PO2 within

10-12 mm Hg of resting values.

A significant increase in blood temperature (i.e. from 37ºC to 39ºC) 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 amount of gas moved per breath is termed

tidal volume.

In a pulmonary function test, a FEV1/FVC ratio of 0.60 is

suggestive of airway obstruction.

Small increases in arterial PCO2 have a ______________ effect on ventilation compared to small decreases in PO2.

greater

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?

Both 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 are correct.

Which of the following is NOT an important function of the pulmonary system?

to cool the airways.

Gas exchange in the lungs occurs

across approximately 300 million alveoli.

Which of the following statements about myoglobin are true?

1) myoglobin binds oxygen.

2) myoglobin shuttles oxygen from the cell membrane to the mitochondria.

3) myoglobin exists in relatively large quantities in slow-twitch muscle fibers.

The carotid bodies are chemoreceptors that are sensitive to changes in arterial _______.

pH, PCO2, and PO2

A ventilation-perfusion (V/Q) ratio of 0.64 would indicate

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

Which of the following statements about pulmonary physiology is correct?

1) The PO2 of inspired air at sea level is approximately 159 mm Hg.

2) The percentage of CO2 in the air is 0.0003.

3) The percentage of O2 in the air at sea level is the same as at high altitude.

An increase in alveolar ventilation (at rest) resulting in hyperventilation will reduce arterial ______ and increase ______.

PCO2; pH

According to Fick's law of diffusion, the rate of diffusion of a gas across a tissue is directly proportional to the

1) tissue area.

2) diffusion coefficient of the gas.

3) difference in partial pressure of the gas on the two sides of the tissue.

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

1) PO2 of approximately 100 mm Hg.

2) oxyhemoglobin saturation of 97-98%.

3) oxygen content of 20 ml O2/100 ml blood.

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

both is much steeper at PO2's below 20 mm Hg and reaches a plateau at a much lower PO2 are correct

An increase in PCO2 in the blood results in the formation of bicarbonate in the red blood cell. Because bicarbonate carries a negative charge (anion), the removal of negatively charged molecule from the red blood cell is required to prevent an electrochemical imbalance across the cell membrane. This problem is avoided by

movement of chloride molecules into the red blood cell.

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 during exercise?

1) Changes in breathing patterns during exercise are important to ensure that optimal mechanics of breathing are realized during exercise

2)Changes in breathing patterns during exercise are designed to reduce the risk of respiratory muscle fatigue

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