Respiratory System Flashcards

Flashcards about the respiratory system, gas exchange, transport, and control of ventilation.

External Respiration

The exchange of oxygen and carbon dioxide between the air in the alveoli and the blood.

Internal Respiration

The exchange of oxygen and carbon dioxide between the blood and the tissues.

Exchange of respiratory gases depends on…

Differences in the partial pressures of a gas, the thickness of the membrane, and the total surface area available for gas exchange.

Features that help gas exchange

Moist alveolar surface, thin respiratory membrane, large surface area, and many capillaries surrounding each alveolus.

Oxygen transport in blood

Almost all (98.5%) is chemically combined with haemoglobin (Hb).

Carbon dioxide transport in blood

Most (78%) is transported as bicarbonate ions in plasma.

The role of the respiratory centre

Controls the basic rhythm of breathing via the medulla oblongata and pons.

Modification of the basic rhythm

Cortical influences, the inflation reflex, and chemical stimuli (changes in pCO2 levels, H+ concentration, and large decreases in pO2).