Chap 16 Physiology

Functions of the Respiratory System

Obtain O2 for use by the body and eliminate CO2 produced by the body cells.

External Respiration

Events involved in the exchange of O2 and CO2 between the external environment and body cells.

Ventilation

Movement of air in and out of the lungs.

Boyle’s Law

The pressure exerted by a gas varies inversely with the volume of gas.

Alveoli

Thin-walled inflatable sacs that are the site of gas exchange.

Type I Alveolar Cells

Cells that form the structure of the alveoli.

Type II Alveolar Cells

Cells that secrete surfactant in the alveoli.

Diaphragm

Dome-shaped sheet of skeletal muscle that separates the thoracic cavity from the abdominal cavity.

Pleural Sac

Double-walled sac that separates each lung from the thoracic wall.

Intrapleural Fluid

Fluid that lubricates the pleural surfaces.

Minute Ventilation (VE)

Volume of air breathed in and out in one minute.

Tidal Volume

Amount of air breathed in or out during normal breathing.

Inspiratory Reserve Volume (IRV)

Amount of air that can be inhaled after a normal inhalation.

Expiratory Reserve Volume (ERV)

Amount of air that can be exhaled after a normal exhalation.

Residual Volume (RV)

Amount of air remaining in the lungs after maximum exhalation.

Total Lung Capacity

Maximum amount of air the lungs can hold.

Hypoxia

Condition of having insufficient O2 at the cell level.

Hyperoxia

Condition of having an above-normal arterial PO2.

Acclimatization to High Altitude

Physiological adjustment to lower atmospheric pressure and oxygen availability.

Oxygen Transport

Transported dissolved in plasma (2%) and bound to hemoglobin (98%).

Carbon Dioxide Transport

Transported dissolved in plasma (10%), bound to hemoglobin (30%), and as bicarbonate ion (60%).