The<unk>  <unk>  is the volume in the lungs at which its smallest airways, the respiratory bronchioles, collapse. It is defined mathematically as the sum of the<unk>  volume and the residual volume. The alveoli lack supporting cartilage and so depend on other factors to keep them open. The<unk>  is less than the Functional Residual<unk> , the amount of gas that normally remains in the lungs during respiration This means that there is normally enough air within the lungs to keep these airways open throughout both inhalation and exhalation. As the lungs age, there is a gradual increase in the<unk>  (i.e. The small airways begin to collapse at a higher volume/before expiration is complete). This also occurs with certain disease processes, such as asthma, chronic obstructive pulmonary disease, and pulmonary edema. Any process that increases the<unk>  by increasing the<unk>  volume (CV) can increase an individual's risk of hypoxemia, as the small airways may collapse during exhalation, leading to air trapping and atelectasis. A mnemonic for factors increasing<unk>  is ACLS-S: Age, Chronic bronchitis, LV failure, Smoking, Surgery. Alternatively, CLOSE: Cigarettes, LV failure, Old age, Surgery, Emphysema (& asthma). Often supine positioning will decrease functional residual<unk>  (FRC) but has no effect on<unk> .
Closing capacity
Contrast resolution
Parafunctional activity
Diffusing capacity
Efficiency of food conversion
Pain tolerance
Mechanical properties of biomaterials
Diastolic function