Vertebrate Physiology - Ch 11

External respiration

Sequence of events involving gas exchange between external environment and cellular mitochondria

Atmospheric pressure

Pressure exerted on objects by atmospheric air

How is air different from water as a respiratory medium?

Less viscous → easier bulk transport, more oxygen

What do respiratory surfaces exposed to air need?

Moisture (skin) and coverage (lungs)

Tidal breathing

External medium inhales and exhaled via same opening

Flow-through breathing

External medium enters one opening and exits separate opeing

How odes intra-alveolar pressure relate to air pressure?

Seeks equilbrium with air pressure

How does intrapleualr pressure compare to air pressure?

Normually just less than atmospheric pressure

How does the intrapleural fluidity hold the pleural surfaces together?

Polar molecules in fluid resist being pulled apart