respiratory chapter 2

Capillary

Tiny blood vessel where gas exchange occurs between blood and tissues.

Alveolus

Tiny air sac in the lungs where oxygen and carbon dioxide exchange takes place.

Mediastinum

Central compartment of the thoracic cavity containing the heart, major blood vessels, esophagus, trachea, and thymus.

Diaphragm

Dome-shaped muscle separating the thoracic and abdominal cavities, essential for breathing.

Thoracic cage

Bony structure protecting the organs in the thoracic cavity, including the heart and lungs.

Bronchus

Large airway that branches from the trachea and leads to the lungs.

Hilum

Region on the medial surface of the lung where blood vessels, bronchi, and nerves enter and exit.

Pleura

Serous membrane covering the lungs (visceral pleura) and lining the thoracic cavity (parietal pleura).

Pleural cavity

Space between the visceral and parietal pleurae containing a thin film of serous fluid for lubrication.

Lobes

Divisions of the lungs - the right lung has superior, middle, and inferior lobes, while the left lung has superior and inferior lobes.

Lobar bronchus

Branch of the bronchial tree supplying air to each lobe of the lung.

Lobules

Smaller divisions within a lobe of the lung, containing terminal bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Respiratory system

Organ system responsible for gas exchange, including breathing and the transport of oxygen and carbon dioxide.

Inspiration

Breathing in, the process of inhaling air into the lungs.

Expiration

Breathing out, the process of exhaling air from the lungs.

Atmospheric pressure

Pressure exerted by the air around us, influencing the movement of air into and out of the lungs.

Boyle's law

Principle stating that pressure and volume of a gas are inversely related.

Phrenic nerves

Nerves that stimulate the diaphragm for breathing.

Trachea

Flexible tube connecting the larynx to the bronchial tree, allowing air passage to the lungs.

Intra-alveolar pressure

The pressure inside the alveoli, which decreases during inspiration to allow air to be forced into the lungs.

Surfactant

A mixture of lipoproteins produced by certain alveolar cells that reduces the tendency of alveoli to collapse by decreasing surface tension.

Compliance

The ease with which the lungs can expand and contract in response to pressure changes during breathing.

Pneumothorax

A condition where air enters the pleural cavity, equalizing pressure and potentially causing lung collapse.

Expiration

The process of air leaving the lungs, which can be aided by the contraction of various muscles to increase air pressure in the lungs.

Intrapleural pressure

The pressure between the pleural membranes, typically lower than atmospheric pressure, helping to keep the lungs inflated.

Expiration

The process of breathing out air from the lungs, involving relaxation of the diaphragm and external respiratory muscles.

Tidal Volume (TV)

The volume of air that enters or leaves the airways and alveoli during a respiratory cycle, typically around 500 milliliters.

Inspiratory Reserve Volume (IRV)

The maximum volume of air that can be inhaled in addition to the resting tidal volume, approximately 3,000 milliliters.

Expiratory Reserve Volume (ERV)

The maximum volume of air that can be exhaled in addition to the resting tidal volume, about 1,100 milliliters.

Residual Volume (RV)

The volume of air that remains in the lungs even after a maximal expiratory effort, approximately 1,200 milliliters.

Inspiratory Capacity (IC)

The maximum volume of air a person can inhale following a resting expiration, calculated as the sum of tidal volume and inspiratory reserve volume.

Functional Residual Capacity (FRC)

The volume of air that remains in the lungs following exhalation of resting tidal volume, calculated as the sum of expiratory reserve volume and residual volume.