Which layer of tissue in blood vessels is responsible for adjusting the diameter and pressure of the blood flow?

• Inner layer (endothelium)

• Middle layer of smooth muscle tissue

• Outer layer of connective tissue

• Lumen

What is the function of arteries in the circulatory system?

• Return deoxygenated blood to the heart

• Transport oxygenated blood quickly under high pressure

• Store blood for emergencies

• Filter waste from the blood

What is the name of the space through which blood flows inside a blood vessel?

• Endothelium

• Valve

• Lumen

• Muscle tissue

Which structural feature helps veins prevent the backflow of blood?

• Thick muscular walls

• Elastic tissue

• Valves

• Narrow lumen

How do the walls of veins compare to those of arteries?

• Veins have thicker walls than arteries

• Veins have thinner walls and a larger lumen than arteries

• Veins have the same wall thickness as arteries

• Veins have more elastic walls than arteries

Which blood vessel is the smallest and has a one-cell-thick wall that allows the exchange of gases, nutrients, and wastes between blood and tissues?

• Artery

• Vein

• Capillary

• Arteriole

What is the main function of arterioles in the circulatory system?

• Collect blood from capillaries and deliver it to veins

• Control blood flow into capillaries by vasoconstriction/vasodilation

• Exchange gases and nutrients with tissues

• Pump blood directly to the heart

Which blood vessel type collects blood from capillaries and delivers it to veins?

• Artery

• Capillary

• Venule

• Arteriole

Which blood vessel has thin walls, less smooth muscle than veins, and a larger lumen than capillaries?

• Artery

• Venule

• Capillary

• Arteriole

What is the main reason capillaries have very narrow lumens that fit only one red blood cell at a time?

• To increase blood pressure

• To allow efficient exchange of gases and nutrients

• To prevent blood from flowing backward

• To store blood