"In physiology, respiration is the movement of oxygen from the outside environment to the cells within tissues, and the removal of carbon dioxide in the opposite direction that's to the environment."
The study of how the respiratory system works, including the mechanics of breathing and gas exchange in the lungs.
"The physiological definition of respiration differs from the biochemical definition, which refers to a metabolic process by which an organism obtains energy (in the form of ATP and NADPH) by oxidizing nutrients and releasing waste products."
"Although physiologic respiration is necessary to sustain cellular respiration and thus life in animals, the processes are distinct: cellular respiration takes place in individual cells of the organism, while physiologic respiration concerns the diffusion and transport of metabolites between the organism and the external environment."
"Gas exchanges in the lung occur by ventilation and perfusion."
"Ventilation refers to the in and out movement of air of the lungs..."
"Perfusion is the circulation of blood in the pulmonary capillaries."
"In mammals, physiological respiration involves respiratory cycles of inhaled and exhaled breaths."
"Contraction of the diaphragm muscle causes a pressure variation, which is equal to the pressures caused by elastic, resistive and inertial components of the respiratory system."
"Exhalation (breathing out) is usually a passive process, though there are many exceptions..."
"...powerlifting, when exhaling underwater (swimming, diving), at high levels of physiological exertion (running, climbing, throwing)..."
"The process of breathing does not fill the alveoli with atmospheric air during each inhalation (about 350 ml per breath), but the inhaled air is carefully diluted and thoroughly mixed with a large volume of gas (about 2.5 liters in adult humans) known as the functional residual capacity which remains in the lungs after each exhalation."
"Physiological respiration involves the mechanisms that ensure that the composition of the functional residual capacity is kept constant, and equilibrates with the gases dissolved in the pulmonary capillary blood, and thus throughout the body."
"During respiration, the C-H bonds are broken by oxidation-reduction reaction, and so carbon dioxide and water are also produced."
"The cellular energy-yielding process is called cellular respiration."
"Thus, in precise usage, the words breathing and ventilation are hyponyms, not synonyms, of respiration..."
"...even though it would need to be consistently replaced with ventilation rate if the precise usage were to be followed."
"Physiologic respiration is necessary to sustain cellular respiration and thus life in animals."
"In physiology, respiration is the movement of oxygen from the outside environment to the cells within tissues..."
"The inhaled air is carefully diluted and thoroughly mixed with a large volume of gas (about 2.5 liters in adult humans) known as the functional residual capacity which remains in the lungs after each exhalation..."
"During respiration, the C-H bonds are broken by oxidation-reduction reaction, and so carbon dioxide and water are also produced."