______12. Which compartment of the heart would receive blood flowing in the wrong direction
through a defective mitral valve?
a. right atrium c. right ventricle
b. left atrium d. left ventricle
______13. Which of the following is found in veins but not in arteries?
a. smooth muscle cells c. connective tissue
b. endothelial cells d. valves
______14. Arteries that carry blood with a high concentration of carbon dioxide are part of
a. the cardiovascular system. c. pulmonary circulation.
b. the circulatory system. d. All of the above
15. The lymphatic system
a. transports blood back to the heart.
b. has veins.
c. connects with systemic circulation.
d. All of the above
______16. Which of the following is NOT a component of blood?
a. platelets c. alveolar cells
b. leukocytes d. red blood cells
______ 17. Which type of cell contains proteins that are important for oxygen transport?
a. erythrocytes c. platelets
b. leukocytes with nuclei d. alveolar cells
______18. Platelets are required for the formation of a. lymph. c. red blood cells.
b. blood clots. d. antibodies.
______19. Immediately before entering alveoli, inspired air passes through
a. veins. c. bronchioles.
b. the trachea. d. bronchi.
______20. What determines whether carbon dioxide is absorbed or released by blood?
a. air pressure within alveoli
b. concentration gradients
c. phagocytes
d. relative amounts of hemoglobin
______21. The diaphragm
a. divides the heart into a right and left side.
b. covers the aortic valve when it is closed.
c. is important for breathing.
d. None of the above
______22. Increased levels of carbon dioxide in the blood cause
a. the breathing rate to decrease.
b. the breathing rate to increase.
c. nerve cells in the cerebrum to increase activity.
d. oxygen levels in the blood to increase and then decrease.
______23. Lymph tissues include all of the following EXCEPT
a. lymph nodes
b. the spleen.
c. blood vessels.
d. tonsils.
Read each question, and write your answer in the space provided.
24. Is it important to know the blood type of a blood donor if only the donor’s plasma will be
used? Explain your answer.
25. What prevents backflow of blood as it returns to the heart?
26. What is systemic circulation?
27. Why is mucus important to the normal functioning of the respiratory system?
28. Briefly describe how air is inspired.