Word: carotid
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...been based on mistaken theories of how human nerve networks function. He concluded that a minute organ buried in the fork of an artery in the neck, and no bigger than a grain of rice, is an important element in breathing control. Discovered in 1743, it is called the carotid body, or glomus caroticum*; there is one on each side of the neck...
...carotid body, Dr. Nakayama's research indicated, is not only a junction point for many nerves (see diagram), but, by its responses to minute changes in the composition of the blood, it does much to regulate breathing. Most notably, an increase in the blood's carbon dioxide content sets off a carotid body reaction that can bring on a choking attack of asthma by causing fast, shallow breathing in lungs unable to handle the added load. To suppress these excessive reactions, Dr. Nakayama wondered, why not cut out one or both carotid bodies? After tests on animals...
...surgical team headed by Dr. John E. Connolly made an incision in the anesthetized patient's neck, to get at one of the carotid arteries that supply blood to the brain. First they drew out some blood, and added donor blood, to fill the pump-oxygenator ("heart-lung machine"). To this was attached a cooler that chilled the oxygenated blood. The surgeons led this chilled blood into the brain arteries. After about 15 minutes the brain temperature dropped to 68°. The doctors then stopped the flow and clamped all the brain arteries shut. The patient...
...Circle of Willis can also be afflicted by a kind of malign predestination. Some people are candidates for certain types of strokes as a result of what happened-or didn't happen-before they were born. The human fetus goes through a phase in which the internal carotid artery on each side feeds into three branch arteries and supplies most of the blood to its hemisphere of the brain...
Before birth these vessels are supposed to rearrange their connections so that the internal carotid supplies only two main branches. But, said Dr. Kirgis, about 14% of all brains studied at autopsy show the internal carotid still feeding three branch arteries on one side of the brain, and in a few cases this is true on both sides. A hemorrhage or, more common, a clot in the internal carotid of such people is apt to do far more damage than in people of normal arterial development, because there is a greater bottleneck for blood supply to essential areas...