Blood squirt (blood spurt, blood spray, blood gush, or blood jet) is the effect when an artery, a blood vessel in the alive human body (or other organism's body) is ruptured. Blood pressure causes the blood to bleed out at a rapid, intermittent rate in a spray or jet, coinciding with the pulse, rather than the slower, but steady flow of venous bleeding. Also known as arterial bleeding, arterial spurting, or arterial gushing, the amount of blood loss can be copious, occur very rapidly, and can lead to death.
In cut carotid arteries with 100 mL of blood through the heart at each beat (at 65 beats a minute), a completely severed artery will spurt blood for about 30 seconds and the blood will not spurt much higher than the human head. If the artery is just nicked, on the other hand, the blood will spurt longer but will be coming out under pressure and spraying much further.
To prevent hand ischemia, there is a "squirt test" that involves squirting blood from the radial artery, which is used in intraoperative assessment of collateral arm blood flow before radial artery harvest. This is more commonly called "Allen's test" by microvascular surgeons, and is used before harvesting radial artery based free tissue transfers (cf Allen's test).
Chinnamasta, a self-decapitated Hindu goddess, is depicted holding her head with three jets of blood spurting out of her bleeding neck, which are drunk by her severed head and two attendants. Saint Miliau, a Christian martyr killed c. 6th century AD, is sometimes represented holding his severed head, as in the retable of the Passion of the Christ at Lampaul-Guimiliau, where blood gushes from his neck.
Insects and animalsEdit
Some animals deliberately autohaemorrhage or squirt blood as a defense mechanism. Armored crickets, which are native to Namibia, South Africa, and Botswana, drive away predators by spewing vomit and spurting hemolymph (the mollusk and arthropod equivalent of blood) from under their legs and through slits in their exoskeleton. Katydids do it too, and in Germany the species has acquired the nickname "Blutspritzer", or "blood squirter". The regal horned lizard, too, uses the blood-spewing tactic, shooting the substance from a pocket near its eyes.
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- Intraoperative confirmation of ulnar collateral blood flow during radial artery harvesting using the "squirt test" Archived July 17, 2011, at the Wayback Machine, Inderpaul Birdi and Andrew J. Ritchie of Papworth Hospital, The Annals of Thoracic Surgery at CTSNet, 2002
- "Medicine: Blood Spurt", Time Magazine, 8 April 1935, retrieved 17 March 2010
- "See It to Believe It: Animals Vomit, Spurt Blood to Thwart Predators", Allison Bond, Discover Magazine blog, 28 July 2009, retrieved 17 March 2010