Acute<unk>  refers to intrinsic<unk> , or control, of arterial vascular tone at a<unk>  level, meaning within a certain tissue type, organ, or organ system. This intrinsic type of control means that the<unk>  vessels can automatically adjust their own vascular tone, by dilating (widening) or constricting (narrowing), in response to some change in the environment. This change occurs in order to match up the tissue's oxygen demand with the actual oxygen supply available in the<unk>  as closely as possible. For example, if a muscle is actively being utilized it will require more oxygen than if it was at rest, so the<unk>  vessels supplying that muscle will vasodilate, or widen in size, to increase the amount of<unk> , and therefore oxygen, being delivered to that muscle. There are several mechanisms by which vascular tone, and therefore<unk> <unk> , is controlled. The sympathetic nervous system and a variety of hormones, for instance, both exert some degree of control over vascular tone. However, the<unk>  intrinsic regulatory system described here is completely independent of these other mechanisms. Many organs or organ systems have their own unique mechanism of<unk> , as explained below.
Local blood flow regulation
Vascular recruitment
Lymphangiogenesis
Vascular permeability
Cardiac contractility modulation
Epineurial repair
Renal protein reabsorption
Cardiac rhythmicity