Question

The diagram given alongside shows the cross-section of two kinds of blood vessels:

1. Identify the blood vessels A and B. In each case give a reason to support your answer.
2. Name the parts numbered 1 and 2.
3. Name the blood vessel that
   1. begins and ends in capillaries.
   2. supplies blood to the walls of the heart.

Answer 1

1. A: Artery
   B: Vein
   A has a narrow lumen and a thick muscular wall, whereas B has a wide lumen and a thin muscular wall.
2. 1: Endothelium
   2: Lumen
3. The first sound LUBB is created when the atrio-ventricular (tricuspid and bicuspid) valves close abruptly at the commencement of ventricular systole. The second DUP sound is created when the semilunar valves at the aortic and pulmonary artery roots seal at the start of ventricular diastole.
4. 1. Hepatic portal vein
   2. Coronary artery