Blood vessel
Blood vessels were part of the circulatory system and functioned to transport blood throughout humanoid bodies. Mind melds could cause pressure changes in a subject's nerves and blood vessels, something which Spock cautioned Simon Van Gelder about before beginning a meld with him in 2266. ()

In 2367, Doctor Beverly Crusher noted a slight dilation of the blood vessels in Geordi La Forge's visual cortex, adding that it was nothing serious. ()

Bajoran pregnancies developed blood vessels connecting the mother and child very quickly, as the gestation period was less than five months. For this reason, Dr. Julian Bashir recommended against removing Kirayoshi O'Brien's transplanted fetus from Kira Nerys's womb, as there was a risk of hemorrhage for her and respiratory trauma for the child. ()

In 2373, a Pah-wraith possessing Keiko O'Brien threatened Miles O'Brien that by destroying even a tiny blood vessel in her brain it would destroy all of Keiko's memories and emotions if he didn't cooperate. ()

Also that year, Bashir worried about an unconscious Garak potentially breaking a critical blood vessel in his brain as a result of psychological stimuli. ()

In 2374, The Doctor diagnosed a Romulan officer with third-degree burns, a hairline fracture of the jaw, and a ruptured blood vessel in his brain which required surgical intervention. ()

Types 
Brachial artery
Capillary
Carotid artery

External link
 
Anatomy