MEDICAL PHYSIOLOGY

Detailed explanation-1: -Some, like the aorta, have a wide diameter. For example, a normal aorta in the abdomen is about 2 centimeters wide (about the size of a nickel). But other blood vessels, such as capillaries, are extremely small. They range from 2 to 12 micrometers, which is even less than the diameter of a human hair.

Detailed explanation-2: -Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins).

Detailed explanation-3: -Capillaries are small, normally around 3-4µm, but some capillaries can be 30-40 µm in diameter. The largest capillaries are found in the liver. (capillar comes from the greek for hairlike). Capillaries connect arterioles to venules.

Detailed explanation-4: -Arteries are the largest blood vessels with the thickest walls, and capillaries are the smallest. Arteries are only located deep inside your muscles, but capillaries are inside tissues all over your body.