Circulatory system
From Memory Alpha, the free Star Trek reference.
The circulatory system is the organ system that circulates blood and nutrients through the body.
The circulatory system of Jem'Hadar soldiers begins to shut down without ketracel-white. (DS9: "The Abandoned", "Hippocratic Oath", "To the Death")
The Breen have no liquid circulatory system. (DS9: "In Purgatory's Shadow")
A Borg drone's cardiopulmonary system is reinforced. (VOY: "The Haunting of Deck Twelve")
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")
