MICROANATOMY

Detailed explanation-1: -Hint: Capillaries are very thin blood vessels. They connect arteries and veins. The hollow opening inside the blood vessel is called lumen.

Detailed explanation-2: -The arteriolar lumen regulates the flow of blood through the capillaries. Venules are the smallest veins and receive blood from capillaries. They also play a role in the exchange of oxygen and nutrients for water products.

Detailed explanation-3: -Arterioles: Arteries branch into smaller vessels called arterioles. Both arteries and arterioles are very flexible. They get bigger or smaller to help maintain your body’s blood pressure.

Detailed explanation-4: -These are blood vessels that carry oxygenated blood from the heart to the tissues. These have thick-walled and narrower lumens because they carry blood from the heart with great pressure.

Detailed explanation-5: -Vessels that, when relaxed, measure <400 m in lumen diameter act as the major site of vascular resistance and include a network of small arteries (lumen ≈100 to 400 m) and arterioles (<100 m).