There are two carotid arteries that feed blood to the brain, one on each side of the neck and head. one patient's carotid arteries are each 11.2 cm long and have an inside diameter of 5.3 mm . near the middle of the left artery, however, is a 2.0-cm-long stenosis, a section of the artery with a smaller diameter of 3.5 mm .

The answer is: Narrowing is usually the result of atherosclerosis.

Explanation:

Carotid artery stenosis is a narrowing of the large arteries that are located on both sides of the neck that carry blood to the head, face and brain. This narrowing is usually the result of an accumulation of plaque inside the arteries, a condition called atherosclerosis or atherosclerosis. Stenosis can get worse over time until the artery is completely blocked, causing a stroke.

The answer is: Narrowing is usually the result of atherosclerosis.