Structural Features of Blood Vessels

What is the innermost layer of a blood vessel called?

• Tunica externa

• Tunica media

• Tunica intima

• Myocardium

Which component forms the lining of the tunica intima?

• Smooth muscle

• Collagen fibers

• Endothelium

• Elastic fibers

Which type of tissue is found in the tunica intima along with endothelium?

• Cartilage

• Loose connective tissue

• Skeletal muscle

• Dense fibrous tissue

What distinguishes the tunica media of arteries from that of veins?

• Arteries have more smooth muscle and elastic fibers

• Veins have a thicker tunica media

• Arteries lack smooth muscle

• Veins contain more capillaries

What is the primary component of the tunica externa?

• Endothelial cells

• Elastic fibers

• Collagen fibers

• Smooth muscle

Which of the following carries oxygen-poor, CO₂-rich blood from the heart to the lungs?

• Pulmonary veins

• Pulmonary arteries

• Aorta

• Venae cavae

Which vessels return oxygen-rich blood from the lungs to the heart?

• Pulmonary arteries

• Venae cavae

• Aorta

• Pulmonary veins

Which chamber of the heart receives oxygen-rich blood from the lungs?

• Right atrium

• Left atrium

• Right ventricle

• Left ventricle

Which chamber pumps oxygenated blood into the systemic circuit?

• Right atrium

• Left atrium

• Right ventricle

• Left ventricle

Where does gas exchange occur between blood and body tissues?

• Pulmonary arteries

• Aorta

• Capillary beds

• Venae cavae