MICROANATOMY

Detailed explanation-1: -Capillaries are the smallest blood vessels in the body. How small are they? About ten of them equal the thickness of one human hair, and most are so small that only one blood cell can pass through them at a time.

Detailed explanation-2: -Most capillaries are only about 8 to 10 micrometers in diameter (a micrometer is 0.001 mm). They’re so tiny that red blood cells have to pass through in a single file line. Capillaries contain two layers of cells: Endothelial cells are inside the capillary.

Detailed explanation-3: -Out of all of the arteries in the body, the smallest arteries are called arterioles. Arterioles connect to the capillaries, which are the smallest blood vessels in the body.

Detailed explanation-4: -Arteries. Aorta (the largest artery, carries blood out of the heart) Arterioles. Capillaries (the smallest blood vessels) Venules. Veins. Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein.