A B-double or consists of a prime mover towing two semi-trailers, where the first semi-trailer is connected to the prime mover by a fifth wheel coupling (aka 'converter dolly') and the second semi-trailer is connected to the first semi-trailer by a fifth wheel coupling.
1 Arteries. 2  Arteries are elastic vessels that transport blood away from the heart. 3  Pulmonary arteries carry blood from the heart to the lungs where oxygen is picked up by red blood cells. 4  Systemic arteries deliver blood to the rest of the body. 5  Veins. 6  Veins are elastic vessels that transport blood to the heart.
There are three basic types of blood vessels: the capillaries, which exchange water and chemicals between the blood and tissues; the arteries, which carry blood away from the beating heart and the veins, which transport blood from the capillaries to the heart, thus enabling the heart to continue beating.lood vessels are an integral part of the circulatory system. These components assist in the transportation of blood within the body, often in and out of the heart.