vas(o)-

A vessel.

Latin vas, vessel.

Most terms are medical ones relating to blood vessels and hence to blood pressure: vasoconstriction is the constriction of blood vessels, which increases blood pressure (the opposite is vasodilation); vasopressin (from pressor, something causing pressure) is a pituitary hormone which acts to increase blood pressure. However, vasectomy (Greek ektomē, excision), refers to the surgical cutting of the vas deferens, ducts which convey sperm from the testicles, typically as a means of sterilization.