This swelling of the walls may partly or completely occlude the lumen of the vessels.
In many cases the colour-production is dependent on certain definite conditions - temperature, presence of oxygen, nature of the food-medium, &c. Ewart's important discovery that some of these lipochrome pigments occlude oxygen, while others do not, may have bearings on the facultative anaerobism of these organisms.
The cuff is then inflated to occlude the brachial artery.