Thoracic independent volume

A term coined by Dr. Gerald Gause of the University of Florida College of Pharmacy, Thoracic Independent Volume is the volume of the thoracic cavity without the lungs. Another way of looking at it is TIV is the volume at which the thoracic cavity's elastic forces are at equilibrium independent of the lung's inward elastic forces.

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This volume is approximately 70% of Total Lung Capacity, or 4060 mL in a typical healthy male of 70 kg. At any volume lower than TIV, the thoracic cavity wants to expand. At any volume higher, it wants to contract.

When taking into account the inward elastic forces of the lungs; above TIV, the forces work congruously (inward recoil of the lung, inward recoil of the thoracic cavity), below TIV, the forces work opposite (inward recoil of the lung, outward recoil of the thoracic cavity).

v • d • e Respiratory system, physiology: respiratory physiology
Volumes	lung volumes - vital capacity - functional residual capacity - respiratory minute volume - closing capacity - dead space - spirometry - body plethysmography - peak flow meter - thoracic independent volume - bronchial challenge test
Airways	ventilation (V) (positive pressure) - breath (inhalation, exhalation) -respiratory rate - respirometer - pulmonary surfactant - compliance - hysteresivity - airway resistance
Blood	pulmonary circulation - perfusion (Q) - hypoxic pulmonary vasoconstriction - pulmonary shunt
Interactions	ventilation/perfusion ratio (V/Q) and scan - zones of the lung - gas exchange - pulmonary gas pressures - alveolar gas equation - hemoglobin - oxygen-haemoglobin dissociation curve (2,3-DPG, Bohr effect, Haldane effect) - carbonic anhydrase (chloride shift) - oxyhemoglobin - respiratory quotient - arterial blood gas - diffusion capacity - Dlco
Control of respiration	pons (pneumotaxic center, apneustic center) - medulla (dorsal respiratory group, ventral respiratory group) - chemoreceptors (central, peripheral) - pulmonary stretch receptors (Hering-Breuer reflex)
Insufficiency	high altitude - oxygen toxicity - hypoxia