Separate plasma by centrifugation. Transfer the serum, plasma or whole blood to a plastic transport tube (see Pediatric Specimen Tubes below). To prevent injury and exposure to potentially infectious material, do not ship frozen serum, plasma, or whole blood received in glass tubes or SST (glass or plastic).
The capillaries are the smallest of the blood vessels and are part of the microcirculation. The capillaries have a width of a single cell in diameter to aid in the fast and easy diffusion of gases, sugars and nutrients to surrounding tissues.fter travelling from the aorta, blood travels through peripheral arteries into smaller arteries called arterioles, and eventually to capillaries. Arterioles help in regulating blood pressure by the variable contraction of the smooth muscle of their walls, and deliver blood to the capillaries.
The microcirculation is composed of terminal arterioles, capillaries, and venules that drain capillary blood. The vessels on the arterial side of the microcirculation are called the arterioles, which are well innervated, are surrounded by smooth muscle[citation needed]cells, and are 10-100 Âµm in diameter.