Which structure contains deoxygenated blood?
Pulmonary arteries
Pulmonary veins
Left ventricle
Aorta
Left atrium
Which of the following is true of arteries?
Their thick walls are due entirely to the bulk of elastic fibers in the middle layer
Their walls are thick and muscular compared with veins
Arteries lack an endothelial layer
The walls of arteries and veins are about the same thickness in a given tissue
Vein walls are thicker than arteries because veins must pump blood up from the lower body
