Chapter 12

Which blood vessels will have walls only one cell think ? A. Capillaries B. Venules C. Veins D. Arteries

A. Arteries

Which of the following is true about capillaries? A. Capillaries are extremely narrow B. Capillaries join arteries to arterioles C. Capillaries are present in only a limited number of internal organs D. Capillaries work individually to carry out their function

A. Capillaries are extremely narrow

What is the correct sequence in which a drop of blood returning from the body encounters the heart chambers? A. Left atrium left ventricle right atrium right ventricle B. Right atrium left atrium left ventricle right ventricle C. Right atrium right ventricle left atrium left ventricle

C. Right atrium right ventricle left atrium left ventricle

The pulmonary semilunar valve prevents blood from re-entering the A. Right atrium B. Left atrium C. Right ventricle D. Left ventricle

C. Right ventricle

Which is NOT true of the heart? A. The heart is a double pump B. The heart helps maintain blood pressure C. The heart helps make red blood cells D. The heart is composed primarily of muscle

C. The heart helps make red blood cells

Which blood vessels carry blood away from the heart? A. Capillaries B. Venules C. Veins D. Arteries

D. Arteries