Bloody Vessels Trivia Quiz

Answer: Arteries carry blood away from the heart, veins towards the heart.

Most, but not all, arteries carry oxygenated blood: the pulmonary artery carries deoxygenated blood (to the lungs) and the pulmonary vein carries oxygenated blood, and the vessels of the umbilical cord are another exception.

Answer: capillaries

Capillaries are very small, but there are millions of them. Therefore, because the total cross-sectional area of all the capillaries is so large, the blood flow through them is correspondingly slow.

Answer: Less blood flows up your leg.

The capillaries are quite leaky, so some blood plasma is lost through the capillary walls into the tissue fluid. Much of this leaked fluid returns later to the circulation via the lymph system, which is a kind of drainage system - so, some of the blood that goes down your leg comes back as lymph, not as blood.

Answer: aorta

Blood flows from high pressure (in the arteries) to low pressure (in the veins). A higher pressure is generated in the aorta than in the pulmonary circulation, because the blood has to be forced through more capillary beds.

Answer: They are pushed open or closed by the blood pressure.

The valves are pocket-shaped flaps of tissue, which are pushed open or closed according to whether the blood pressure is higher on one side of the valve or on the other.

Answer: tunica intima

The tunica intima, also sometimes called the tunica interna, is a layer of flattened surface (endothelial) cells lining the lumen (or tube) of the artery. Outside this, there is the tunica media (mainly muscle and elastic tissue) and the tunica adventitia (connective tissue). The lumen is not part of the artery wall.

Answer: where the arteries supplying blood to the heart become narrowed or blocked

The coronary artery supplies oxygenated blood to the heart muscle itself. In coronary heart disease, this vessel becomes partly or completely blocked, cutting off the oxygen supply.

Answer: in the walls of the arteries

The larger arteries need their own blood supply - to carry oxygen etc to the cells that make up the artery wall. These "vessels within vessels" are the vasa vasorum.

Answer: It has no function.

In the foetus (where the lungs cannot be used for breathing), the ductus arteriosus diverts blood away from the pulmonary artery (and the lungs) to the aorta. After birth, this vessel closes up, but it remains as a vestigial structure, known as the ductus arteriosum, linking the pulmonary artery and the aorta.

Answer: loss of elasticity of the artery walls

In arteriosclerosis, or "hardening of the arteries", the artery walls lose their elasticity due to deposition of collagen fibres: this is an ageing process. The deposition of fatty plaques (which may be due to high blood cholesterol) is known as atherosclerosis.