A&P lecture 3/15

Autonomic function

A type of function that is automatic and not under conscious control, such as the control of respiration.

Bronchodilation

The widening of the bronchial airways caused by the relaxation of smooth muscles, typically due to sympathetic stimulation.

Bronchoconstriction

The narrowing of the bronchial airways caused by the contraction of smooth muscles, typically due to parasympathetic stimulation.

Pleura

The two-layered membrane covering the lungs, consisting of the visceral pleura (covering lungs) and parietal pleura (lining thoracic walls).

Intrapulmonary pressure

The pressure within the alveoli of the lungs.

Intrapleural pressure

The pressure within the pleural cavity, always less than intrapulmonary and atmospheric pressure.

Pulmonary ventilation

The process of moving air into and out of the lungs to refresh the air in the alveoli.

Boyle's law

The principle stating that the pressure of a gas is inversely proportional to its volume at constant temperature; when volume increases, pressure decreases.

Tidal volume

The volume of air exchanged during normal quiet breathing.

Vital capacity

The total amount of exchangeable air in the lungs, encompassing the maximum inhalation and exhalation.

Residual volume

The amount of air remaining in the lungs after a forced exhalation.

Total lung capacity

The total volume of air that the lungs can hold, which includes both exchangeable and non-exchangeable air.

Dead space

The volume of air in the respiratory system that does not participate in gas exchange, such as air in the trachea.

Dalton's law of partial pressures

The law stating that the total pressure exerted by a gas mixture is the sum of the partial pressures of each individual gas.

Bohr effect

The physiological phenomenon where increased levels of carbon dioxide and lower pH increase the release of oxygen from hemoglobin.

Halogen effect

The phenomenon where the release of one oxygen molecule from hemoglobin increases the likelihood of other oxygen molecules dissociating.

Surfactant

A substance secreted by type II alveolar cells that reduces surface tension in the lungs to prevent alveolar collapse.

Ventilation-perfusion coupling

The matching of air flow to blood flow in the lungs to optimize gas exchange.

Hyperventilation

An increase in the rate and depth of breathing that can lead to decreased carbon dioxide levels in the blood.

Hypoxic drive

A change in the normal control of breathing where low oxygen levels become a primary trigger for increasing respiration.