Two carotid arteries, one on each side of the neck, supply blood and oxygen to the brain. An area within each artery, called the carotid sinus, is sensitive to any change in blood pressure. The carotid body is an area of tissue near the carotid sinus. It monitors any change in the chemicals of the blood.
Atherosclerosis
Atherosclerosis is the most common problem of the carotid artery. In this disease, areas of saturated fat and cholesterol called plaques collect in the artery. Plaques reduce the amount of blood that can flow through the artery. A plaque can grow so large, it can completely block all blood flow and cause a stroke. In fact, in "Schwartz's Principles of Surgery," Peter Lin, M.D., Associate Professor of Surgery at the Baylor College of Medicine states that atherosclerosis in the carotid artery causes approximately 30 to 60 percent of ischemic strokes.
Fibromuscular Dysplasia
Fibromuscular dysplasia, the abnormal development of the fibrous tissue and muscles in the wall of an artery, usually affects women in their 40s and 50s. Sometimes, the smooth muscle replaces the connective tissue. Other times, there is too much smooth muscle. Scientists hypothesize that hormones may be involved somehow. When this disease affects one carotid artery, it usually affects both. In "Schwartz's Principles of Surgery," Dr. Lin writes that approximately 50 percent of people with fibromuscular dysplasia in one or both carotid arteries also have an aneurysm in a carotid artery or in the middle cerebral artery of the brain.
Takayasu's Arteritis
Arteritis refers to the inflammation of an artery. In Takayasu's arteritis, the inflammation is mainly in the aorta, but it can also affect the carotid artery. Physicians do not know what causes this disease, but it affects women eight times more often than men. Approximately two to three people in every 1 million are diagnosed with this disease every year in North America, according to the Merck Manuals Online Medical Library. The inflammation leads to thickening and scarring inside the wall of the artery. People can develop aneurysms or may have abnormal blood flow because the passage inside the artery becomes too narrow. As in atherosclerosis, blood flow can become completely blocked.
Carotid Coils
If the carotid artery is abnormally long, part of it will form a coil. As explained by Dr. Lin in "Schwartz's Principles of Surgery," the carotid artery is coiled in the early stages of the fetus. It straightens as the heart lowers into its proper place. In children, coiled carotid arteries may be the result of a congenital disorder. Adults can develop this problem if the artery becomes less elastic. Women have this problem more often than men.
References
- "Schwartz's Principles of Surgery"; F. Charles Brunicardi, M.D.; 2010
- The Merck Manuals Online Medical Library: Takayasu's Arteritis
