Pulmonary shunt

From Wikipedia, the free encyclopedia

Pulmonary shunts exist when there is normal perfusion to an alveolus, but ventilation fails to supply the perfused region.

This will lead to a situation where the blood supply leaving a shunted area of the lung will have lower levels of oxygen and higher levels of carbon dioxide (i.e., the normal gas exchange doesn't occur).

A small degree of shunt is normal and may be described as 'physiological shunt'. A physiological shunt fraction of 5% is normal and upto 10% is compatible with normal gas exchange.

[edit] See also

• Cardiac shunt
• Systemic-to-pulmonary shunt
• Shunt (medical)

[edit] External links

• Physiology at MCG 4/4ch5/s4ch5_9
• calculator at medstudents.com.br

v • d • e Respiratory system, physiology: respiratory physiology

Volumes: lung volumes - vital capacity - functional residual capacity - respiratory minute volume - dead space - spirometry - body plethysmography - peak flow meter ventilation (V) (positive pressure) breath (inhalation, exhalation) - respiratory rate - respirometer - pulmonary surfactant - compliance - hysteresivity - airway resistance pulmonary circulation - perfusion (Q) - hypoxic pulmonary vasoconstriction - pulmonary shunt 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 high altitude - oxygen toxicity - hypoxia