The circulatory system, or blood circulation, was the organ system that circulated circulatory fluid, typically blood, through the body. The flow of blood through this system was known as the bloodstream.
In 2367, after brainwashing by the Romulans, Geordi La Forge suffered from insomnia which was caused by a minor vascular irregularity in the visual cortex, a slight dilation of the blood vessels. (TNG: "The Mind's Eye")
In 2370, in the "Anatomical Scan - 9861" for Juliana Tainer, the blood circulation was listed under heart and blood supply in the coronal plane portion of the graphic. For her blood circulation, it was noted that it was 27% above normal. (TNG: "Inheritance")