survey

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

10-12 mm Hg of resting values.

Under normal conditions, the partial pressure of oxygen in the alveoli is

100 mmHg.

A by-product of anaerobic glycolysis in red blood cells that is thought to alter the O2-Hb dissociation curve is

2-3 DPG

Under normal conditions, the characteristics of arterial blood include

=PO2 of 100 mmHg. =oxyhemoglobin saturation of 97-98%. = oxygen content of 20 ml O2/100 ml blood.

In general, because of blood hemoglobin concentration differences, males transport less oxygen per unit of blood volume than females.

False

Research demonstrates that respiratory muscle fatigue does not occur during exercise.

False

Research indicates that nasal strips increase endurance performance.

False

The pulmonary system may limit VO2 max only in elite endurance athletes.

False

Which of the following is correct?

The PO2 at sea level is 159 mmHg.

According to Fick's law of diffusion, the rate of diffusion for a gas is greater when the surface area for diffusion is large and the "driving pressure" (i.e., partial pressure) between the two sides of tissue is high.

True

An increase in alveolar ventilation serves to lower arterial PCO2 and increase blood pH.

True

During exercise, more oxygen is unloaded from hemoglobin to the tissues than at rest.

True

The ideal ventilation-perfusion ratio in the lung is 1.

True

The intrapleural pressure is lower than the intrapulmonary pressure.

True

The alinear rise in ventilation observed during incremental exercise (i.e., ventilatory threshold) is thought to be principally due to

a decrease in arterial pH.

Exercise-induced hypoxemia that may occur in elite endurance athletes during heavy exercise is likely dueto

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

23. At a low PO2, myoglobin has _______________ affinity for O2 than hemoglobin.

a higher

Activation of rectus abdominis muscles would result in

active expiration.

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

alveolar ventilation.

A decrease in arterial PO2 below 70 mm Hg would likely result in

an increase in alveolar ventilation.

Carbon dioxide is transported in the blood principally as

bicarbonate.

The most important muscle of inspiration is/are the

diaphragm.

In response to exercise training, the normal lung

does not undergo measurable changes.

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

greater

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

greater than

Ventilation may drift upward during constant-load submaximal exercise performed in a hot and humid environment due to

higher blood temperature.

Exercise-induced asthma would reduce airflow by

increasing airway resistance.

Mitochondrial PO2 is _____________ capillary PO2.

less than

The term ventilation refers to the

mechanical process of moving air in and out of the lungs.

The respiratory control center is located in the

medulla oblongata.

The ventilatory central chemoreceptors respond to changes in the

pH of cerebral spinal fluid.

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

pH, PCO2, and PO2.

In a pulmonary function test, a FEV1/FVC ratio of 0.70 is

suggestive of airway obstruction.

Most of the O2 that is transported in the blood is in

the form of oxyhemoglobin.

The amount of air inspired and expired at rest is called

tidal volume.

The primary purpose of the pulmonary system is

to provide an interface for gas exchange.

Myoglobin is a red pigment found in skeletal muscle that serves to

transport O2 from the cell membrane to the mitochondria.