Pulmonary/Respiration Responses During Exercise – Chapter 10

What are the two main processes that make up pulmonary respiration?

Ventilation and the exchange of O2 and CO2 in the lungs.

How is cellular respiration defined in the context of exercise physiology?

The utilization of O2 and production of CO2 by the tissues.

List two primary purposes of the respiratory system during exercise.

Gas exchange between the environment and the body, and regulation of acid–base balance.

What is ventilation?

The mechanical process of moving air into and out of the lungs.

Define diffusion in the respiratory context.

Random movement of molecules from an area of higher concentration to an area of lower concentration.

Name the major organs of the respiratory system in order of air passage (upper to lower).

Nose/nasal cavities, pharynx, larynx, trachea, bronchial tree, lungs (alveoli).

Where does gas exchange occur in the lungs?

At the alveoli.

What muscle is considered the major muscle of inspiration?

The diaphragm.

Identify the two pleural membranes surrounding the lungs.

Visceral pleura (covers lung surface) and parietal pleura (lines thoracic wall).

Why is intrapleural pressure normally lower than atmospheric pressure?

To prevent the collapse of the alveoli.

What are the two functional zones of the respiratory tract?

Conducting zone and respiratory zone.

State two functions of the conducting zone besides air transport.

Humidifies and filters the incoming air (also warms it).

Which substance prevents alveolar collapse by reducing surface tension?

Pulmonary surfactant.

During inspiration, how do intrapulmonary pressure and lung volume change?

Lung volume increases and intrapulmonary pressure decreases.

Name two accessory muscles recruited during forced expiration.

Internal intercostals and abdominal muscles (e.g., rectus abdominis).

Do respiratory muscles fatigue during exercise? If so, under what conditions?

Yes; during prolonged (>120 min) or high-intensity (90–100 % VO2 max) exercise.

How does endurance training affect respiratory muscles?

Increases oxidative capacity, improving endurance and reducing work of breathing.

State the relationship of airflow to pressure gradient and airway resistance.

Airflow = (P1 – P2) / Resistance.

What characterizes exercise-induced asthma?

Bronchospasm occurring during or immediately after exercise, narrowing airways and impairing performance.

Which two diseases compose chronic obstructive pulmonary disease (COPD)?

Chronic bronchitis and emphysema.

Give the equation for minute ventilation (V̇E).

V̇E = Tidal volume (VT) × Breathing frequency (f).

What is alveolar ventilation (VA)?

The volume of air that reaches the respiratory zone per minute.

Define vital capacity (VC).

The maximum amount of gas that can be expired after a maximum inspiration.

What is residual volume (RV)?

The volume of gas remaining in the lungs after maximum expiration.

Which spirometric value represents the volume expired in the first second of a maximal expiration?

Forced expiratory volume in one second (FEV1