Circulation and Gas Exchange

These flashcards cover key vocabulary terms and concepts related to circulation and gas exchange as discussed in the lecture.

Gas Exchange

The uptake of molecular oxygen from the environment and the discharge of carbon dioxide to the environment.

Partial Pressure

The pressure exerted by a particular gas in a mixture of gases.

Respiratory Surfaces

The thin, moist surfaces through which gas exchange occurs, such as gills, tracheae, and lungs.

Alveoli

Air sacs at the tips of the tiniest bronchioles where gas exchange takes place.

Negative Pressure Breathing

A mechanism in which mammals pull air into the lungs by creating lower pressure inside the lungs compared to the outside.

Tidal Volume

The volume of air inhaled or exhaled in a single breath.

Surfactants

Secretions that coat the surface of alveoli to reduce surface tension and prevent collapse.

Hemoglobin

The respiratory pigment that binds oxygen in the blood and is composed of four subunits, each containing an iron heme group.

Bohr Shift

A phenomenon where an increase in carbon dioxide lowers blood pH, decreasing hemoglobin's affinity for oxygen.

Myoglobin

A protein in muscles that stores oxygen, allowing diving mammals to store large amounts of oxygen.