Respiratory System: Gas Exchange and Internal Respiration

Vocabulary flashcards covering gas exchange mechanisms, structural adaptations, and pressure concepts in the respiratory system.

Gas Exchange

The process of swapping gases between the blood and the lungs inside the body.

Alveoli

Air sacs inside the lungs where gas exchange occurs with blood in the capillaries.

Capillaries

Blood vessels surrounding the alveoli that have thin, one-cell thick walls to make gas diffusion easier.

Diffusion

The movement of molecules from a higher concentration of molecules to a lower concentration of molecules.

Internal Respiration

Gas exchange between the alveoli and the capillaries that happens after external respiration to provide oxygenated blood for systemic circulation.

Deoxygenated Blood

Blood containing $CO_2$ that comes from the right side of the heart during pulmonary circulation.

Oxygenated Blood

Blood enriched with $O_2$ that travels back to the left side of the heart in the pulmonary vein before systemic circulation.

Outside Environment Pressure

The ambient pressure outside the body, typically $760\,mmHg$.

Chest Cavity Pressure

The internal pressure within the human chest cavity, which is always lower than the outside environment, typically $752\,mmHg$.

Alveolar Adaptations

Features that assist gas exchange, including thin one-cell thick walls, moist surfaces for $O_2$ diffusion, and high quantity to increase total surface area.