Respiratory System Lecture Notes

Flashcards for respiratory system lecture review.

Pulmonary ventilation

The inflow and outflow of air between the atmosphere and the lung alveoli.

Diffusion

Diffusion of oxygen and carbon dioxide between the alveoli and the blood.

Gas Transport

Transport of oxygen and carbon dioxide to and from the body’s tissue cells.

Internal Respiration

Refers to the intracellular metabolic processes carried out within the mitochondria, which use O2 and produce CO2 while deriving energy from nutrient molecules.

External Respiration

Refers to the entire sequence of events in the exchange of O2 and CO2 between the external environment and the cells of the body.

Atmospheric pressure

Pressure exerted by the weight of the air in the atmosphere on objects on Earth’s surface.

Intra-alveolar pressure

Pressure within the alveoli.

Intrapleural pressure

Pressure within the pleural sac.

Inhalation

Always active and requires skeletal muscle contraction.

Exhalation

Passive or active.

Surfactant

Complex mixture of lipids and proteins that intersperses between water molecules and lowers the alveolar surface tension, thus reducing the tendency to recoil.

Oxygen Transport

Normally 97 % in combination with hemoglobin (oxyhemoglobin)

Carbon Dioxide Transport

From tissue cells out in dissolved form (7%)

Control of Respiration

The respiratory control centers in the brain stem establish a rhythmic breathing pattern.

Dorsal respiratory group

Associated with inspiration.

Ventral respiratory group

Associated with expiration.

Apneustic center

Has an excitatory function.

Pneumotaxic center

Can inhibit inspiration.

pre-Bötzinger complex

Displays pacemaker activity and drives the inspiratory neurons located in the dorsal respiratory group (DRG) of the medullary respiratory control center

Tidal volume (resting)

Amount of air one can move in or out of lungs in single respiratory cycle (resting conditions)

Inspiratory reserve volume (IRV)

Amount of air one can take in over and above tidal volume

Expiratory reserve volume (ERV)

Amount of air one can voluntarily expel after completed normal respiratory cycle

Residual volume

Amount of air remaining in lungs after maximal exhalation (1200 males; 1100 females)

Inspiratory capacity

Tidal volume + inspiratory reserve volume

Vital capacity

Maximum amount of air one can take into or out of lungs during forced exhalation and inhalation

Total lung capacity

Total volume of lungs = vital capacity and residual capacity (avg = 6000ml males; 4200ml females