Why do arteries have such thick walls?

• To store blood

• To prevent blood loss

• To withstand high pressure

• To slow down blood flow

• To withstand low pressure

Why do veins have the lowest blood pressure on average?

• They are closer to the heart

• They have thicker walls

• They are farther from the heart

• They carry oxygenated blood

• They have more valves

Which type of blood vessel carries blood away from the heart?

• Veins

• Capillaries

• Arteries

• Venules

• Arterioles

What is the primary function of red blood cells?

• To fight infections

• To transport oxygen

• To clot blood

• To regulate body temperature

• To produce hormones

What component of red blood cells binds to oxygen?

• Plasma

• Platelets

• White blood cells

• Hemoglobin

• Fibrinogen

Which blood vessels have valves to prevent backflow of blood?

• Arteries

• Veins

• Capillaries

• Arterioles

• Venules

What is the main structural difference between arteries and veins?

• Arteries have valves

• Veins have thicker walls

• Arteries have thicker walls

• Veins carry oxygenated blood

• Arteries carry deoxygenated blood

What shape are red blood cells?

• Spherical

• Cuboidal

• Biconcave

• Cylindrical

• Irregular

Which type of blood vessel is involved in the exchange of nutrients and gases?

• Arteries

• Veins

• Capillaries

• Arterioles

• Venules

Why do red blood cells lack a nucleus and organelles?

• To reduce their size

• To increase their lifespan

• To maximize space for hemoglobin

• To prevent infections

• To make them more flexible