Search results
Results from the WOW.Com Content Network
Ventilation–perfusion coupling is the relationship between ventilation and perfusion processes, which take place in the respiratory system and the cardiovascular system. [1] Ventilation is the movement of gas during breathing, and perfusion is the process of pulmonary blood circulation, which delivers oxygen to body tissues. [2]
A number of medical conditions may affect the pulmonary circulation: Pulmonary hypertension describes an increase in resistance in the pulmonary arteries. [9] Pulmonary embolism is occlusion or partial occlusion of the pulmonary artery or its branches by an embolus, usually from the embolization of a blood clot from deep vein thrombosis. [10]
Perfusion may also refer to fixation via perfusion, used in histological studies. Perfusion is measured as the rate at which blood is delivered to tissue, [2] or volume of blood per unit time (blood flow) per unit tissue mass. The SI unit is m 3 /(s·kg) [citation needed], although for human organs perfusion is typically reported in ml/min/g. [3]
This is an accepted version of this page This is the latest accepted revision, reviewed on 7 January 2025. Circumstances, mechanisms, and factors of tobacco consumption on human health "Health effects of smoking" and "Dangers of smoking" redirect here. For cannabis, see Effects of cannabis. For smoking crack cocaine, see Crack cocaine § Health issues. "Smoking and health" redirects here. For ...
This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung. On the other side Ventilation-perfusion mismatch is the term used when the ventilation and the perfusion of a gas exchanging unit are not matched. The actual values in the lung vary depending on the position within the lung.
Inhaling cigarette smoke increases blood levels of carbon monoxide which negatively affects oxygenation throughout the body leading to hypoxia. [1] One response to hypoxia is the upregulation in synthesis of the major methyl donor S-adenosylmethionine. Upregulation of this methyl donor through heightened expression of methionine ...
The ventilation/perfusion ratio (V/Q ratio) is higher in zone #1 (the apex of lung) when a person is standing than it is in zone #3 (the base of lung) because perfusion is nearly absent. However, ventilation and perfusion are highest in base of the lung, resulting in a comparatively lower V/Q ratio.
Ventilation Scan is abnormal but perfusion scan is normal indicating abnormal airway suggesting COPD or asthma. Ventilation Scan is normal but perfusion is abnormal indicating any obstruction to the blood flow (perfusion), may be because of the pulmonary embolism obstructing the flow. Both scans are abnormal. It may be found in pneumonia or COPD.