DIFFUSING CAPACITY Meaning and
Definition
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Diffusing capacity, also known as lung diffusing capacity or transfer factor, is a medical term used to describe the ability of the lungs to transfer gases, particularly oxygen (O2) and carbon dioxide (CO2), between the lungs and the bloodstream. It measures how effectively these gases are diffused by the respiratory membrane.
The diffusing capacity of the lungs is an important indicator of respiratory function and is commonly assessed in pulmonary function tests. It provides information about the efficiency of gas exchange in the alveoli, the tiny air sacs in the lungs where oxygen is taken up from the inhaled air and carbon dioxide is released.
The measurement of diffusing capacity involves breathing in a small quantity of a test gas, such as carbon monoxide (CO), which has a high affinity for hemoglobin. The subject breathes in the test gas, and the rate at which it is taken up by the bloodstream is measured. This measurement allows for an estimation of the lung's capacity to transfer gases.
A reduced diffusing capacity may indicate certain conditions or diseases affecting the lungs, such as chronic obstructive pulmonary disease (COPD), lung fibrosis, pulmonary embolism, or other respiratory disorders. Monitoring diffusing capacity can aid in the diagnosis and management of these conditions.
In conclusion, diffusing capacity is a measure of the lung's ability to transfer gases across the respiratory membrane, providing crucial information about respiratory function and aiding in the evaluation of various lung disorders.
Etymology of DIFFUSING CAPACITY
The word "diffusing" derives from the Latin word "diffusus", which means "spread out" or "dispersed". It is the past participle of the verb "diffundere", where "dis-" means "apart" and "-fundere" means "to pour" or "to spread".
The term "capacity" comes from the Latin word "capacitas", which means "ability" or "capability". It is derived from the Latin word "capax", which means "able to hold" or "capable of containing".
Therefore, the etymology of the word "diffusing capacity" indicates that it refers to the ability or capability of a substance or gas to spread out, pour out, or disperse in a specific context, usually related to the respiratory system and gas exchange.
