Blood vessels include arteries (and arterioles) that takeblood away from the heart; capillaries, where exchangeof substances with the tissues occurs; and veins (andvenules) that take blood to the heart.

The movement of blood in the cardiovascular sys-tem is dependent on the beat of the heart. During thecardiac cycle, the SA node (pacemaker) initiates thebeat and causes the atria to contract.

The AV node conveys the stimulus and initiatescontraction of the ventricles. The heart sounds, lub-dup,are due to the closing of the atrioventricular valves,followed by the closing of the semilunar valves.

Blood pressure accounts for the flow of blood inthe arteries, but because blood pressure drops off after thecapillaries, it cannot cause blood flow in the veins. Skele-tal muscle contraction pushes blood past a venous valve,which then shuts, preventing backward flow. The ve-locity of blood flow is slowest in the capillaries, whereexchange of nutrients and wastes takes place.

The cardiovascular system is divided into the pul-monary circuit and the systemic circuit. In the pul-monary circuit, two pulmonary arteries take blood fromthe right ventricle to the lungs, and four pulmonary veinsreturn it to the left atrium. To trace the path of blood inthe systemic circuit, start with the aorta from the leftventricle. Follow its path until it branches to an artery goingto a specific organ. It can be assumed that the artery di-vides into arterioles and capillaries and that the capil-

laries lead to venules. The vein that takes blood to the venacava most likely has the same name as the artery that de-livered blood to the organ. In the adult systemic circuit,unlike the pulmonary circuit, the arteries carry oxy-genated blood and the veins carry deoxygenated blood.

Blood has two main parts: plasma and cells. Plasmacontains mostly water (90–92%) and proteins (7–8%),but it also contains nutrients and wastes.

The red blood cells contain hemoglobin and func-tion in oxygen transport. Defense against disease de-pends on the various types of white blood cells. Granularneutrophils and monocytes are phagocytic. Agranularlymphocytes are involved in the development of immu-nity to disease.

The platelets and two plasma proteins, prothrombinand fibrinogen, function in blood clotting, an enzymaticprocess that results in fibrin threads.

When blood reaches a capillary, water moves outat the arterial end, due to blood pressure. At the venuleend, water moves in, due to osmotic pressure. In between,nutrients diffuse out and wastes diffuse in.

Hypertension and atherosclerosis are two car-diovascular disorders that lead to heart attack and tostroke. Medical and surgical procedures are available tocontrol cardiovascular disease, but the best policy is pre-vention by following a heart-healthy diet, getting regu-lar exercise, maintaining a proper weight, and not smokingcigarettes.

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13CARDIOVASCULAR SYSTEM

CHAPTER REVIEW

STUDY EXERCISES

Study the text section by section as you answer the questions that follow.

13.1 THE BLOOD VESSELS (P. 240)

• A series of vessels delivers blood from the heart to the capillaries, where exchange of substances takes place,and then another series of vessels delivers blood from the capillaries back to the heart.

1. Label the blood vessels in this diagram, using the alphabetized list of terms.arteriolesarterycapillariesheartveinvenules

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2. Match the vessel in the key to the statements that follow.Key artery vein capillary

a. _______________________ Has the thickest walls.

b. _______________________ Has valves.

c. _______________________ Takes blood away from the heart.

d. _______________________ Takes blood to the heart.

e. _______________________ Exchanges carbon dioxide and oxygen with tissues.

f. _______________________ Nervous stimulation causes these to constrict during hemorrhaging; these also act as a

blood reservoir.

3. Explain how it is possible to bypass capillary beds by shunting blood directly from arteriole to venule.

13.2 THE HEART (P. 242)

• The human heart is a double pump; the right side pumps blood to the lungs, and the left side pumps blood thethe rest of the body.

4. Trace the path of blood through the heart from the vena cava to the lungs. a.

from the lungs to the aorta. b.

5. Label the parts of the heart using the alphabetized list of terms.aortaaortic semilunar valveatrioventricular (mitral) valveatrioventricular (tricuspid) valveAV nodechordae tendineaeinferior vena cavaleft atriumleft ventriclepulmonary arteryright atriumright ventricleSA nodeseptumsuperior vena cava

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6. How does the thickness of the walls of the ventricles relate to their functions?

7. Referring to Figure 13.6 in the text, fill in the following table with the words systole (contraction) and diastole(relaxation) to show what happens during the 0.85 seconds of one heartbeat.

8. Heart sounds. When the atria contract, this forces blood through the a._______________ valves into the chambers

called the b._______________. The closing of these valves is the lub sound. Next, the ventricles contract and force the

blood into the arteries. Now the c._______________ valves close, making the dub sound.9. Match the following phrases to this key.

Key SA node AV node

a. ___________________ pacemaker

b. ___________________ contraction of ventricles

c. ___________________ base of right atrium near the septum

d. ___________________ Purkinje fibers10. Electrocardiogram. Of what significance is each of the following?

P wave a._____________________________________

QRS wave b.____________________________________

T wave c.______________________________________

a.

b.

c.

d.e.

f.

g.

h.

i.

j.

k

l.

m.n.

o.

time Atria Ventricles

0.15 sec a. d.

0.30 sec b. e.

0.40 sec c. f.

R

P T

S Q

.04 seconds

0.1mV

11. Match the following actions to the divisions of the nervous system.Key parasympathetic system sympathetic system

a. _______________________ normal body functions

b. _______________________ active under times of stress

c. _______________________ releases norepinephrine to speed up heart

d. _______________________ slows heart rate

12. Does the hormone thyroxine from the thyroid speed or slow the heart rate? a.________________ Does the adrenal

gland hormone, epinephrine, speed or slow the heart rate? b.___________________

Questions 13–16 are based on this diagram.

13. What force accounts for blood flow in arteries?

14. Why does this force fluctuate?

15. What causes the pressure and velocity to drop off?

16. What force accounts for blood flow in the veins?

17. What keeps blood from flowing backwards in veins?

pressure

velocity

blood flow

totalcross-sectionalarea ofvessels

arteries capillaries veinsarterioles venules

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13.3 VASCULAR PATHWAYS (P. 246)

• The pulmonary arteries transport blood low in oxygen to the lungs, and the pulmonary veins return blood highin oxygen to the heart.

• The systemic circuit transports blood from the left ventricle of the heart to the body and then returns it to theright atrium of the heart.

18. Trace the path of blood to the lungs: from the legs:right ventricle legsa._________________________________ c.____________________________________

lungsb._________________________________ d.____________________________________

left atrium right atrium

19. Trace the path of blood from the aorta to the liver: from the liver:aorta livera.__________________________ c._______________________________________

digestive tract vena cavab.__________________________

liver

13.4 BLOOD (P. 249)

• Blood is composed of cells and a fluid containing proteins and various other molecules and ions.• Blood clotting is a series of reactions that produces a clot—fibrin threads in which red blood cells are trapped.

20. Plasma is mostly a.________________ and b.________________.21. Place the correct plasma protein in the blank: fibrinogen, albumin, globulin, or all plasma proteins.

a.___________________ transports cholesterol.b.___________________ helps blood clot.c.___________________ transports bilirubin.d.___________________ helps maintain the pH and osmotic pressure of the blood.

22. The red blood cells, scientifically called a._______________, are made in the b._______________. Upon maturation,

they are biconcave disks that lack a(n) c._______________ and contain d.__________________. After about 120 days,

red blood cells are destroyed in the e._______________ and _________________. The condition off._______________ is characterized by an insufficient number of red blood cells or not enough hemoglobin.

23. Circle the items that describe hemoglobin correctly:a. heme contains ironb. globin contains ironc. becomes oxyhemoglobin in the tissuesd. becomes deoxyhemoglobin in the tissuese. makes red blood cells redf. makes eosinophils red

24. White blood cells, scientifically called a._________________, are made in the b._________________.

25. Name three differences between red blood cells and white blood cells. White blood cells area.______________________ in size than red blood cells; they do have a b.________________; and they do not containc.________________.

26. Place the name of the correct white blood cell (neutrophil, eosinophil, basophil, lymphocyte, or monocyte) next to theproper description.a.___________________ An agranular cell with a large, round nucleus that occurs in two versions. The B lymphocytes

produce antibodies and the T lymphocytes destroy cells that contain viruses.b.___________________ An abundant granular cell with a multilobed nucleus that phagocytizes pathogens.c.___________________ A large agranular cell that takes up residence in the tissues and differentiates into a voracious

macrophage.d.___________________ A cell with blue-staining granules that takes up residence in the tissues; these become mast

cells and release histamine.e.___________________ A cell with a bilobed nucleus and red-staining granules that becomes abundant during

allergies and parasitic infections.

27. A type of cancer called a.__________________ occurs when abnormally large numbers of immatureb.________________ fill red bone marrow. The patient becomes both anemic and incapable of fighting disease organisms.

28. The following shows the reactions that occur as blood clots:platelets ————————> prothrombin activatorprothrombin ———————> thrombinfibrinogen ————————> fibrin threads

Does the left-hand side or the right-hand side list substances that are always present in the blood? a._________________

Which substances function as enzymes? b._________________ Which substance is the actual clot? c._________________

29. Several nutrients are necessary for clotting to occur. Vitamin a.______________ is needed for the production of

prothrombin. The element b.______________ is needed for the conversion of prothrombin to thrombin.

Capillary Exchange (p.255)

• Exchange of substances between blood and tissue fluid across capillary walls supplies cells with nutrients andremoves wastes.

30. Label this diagram using these terms: arterial end of the capillary; blood pressure (two times); net pressurein; osmotic pressure (two times); water, oxygen, and nutrients; venous end of the capillary; water and wastes;tissue fluid.

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Venousend of thecapillary

a.

protein

c.

mm

Hg

30 m

mH

g

21 m

mH

g

15 m

mH

g

21 m

mH

g

h.9

6

0

10

20

30

j.

red blood cell salt

d.b.

e.f.

i.g.

31. Explain the diagram.________________________________________________________________________

32. Why is there excess tissue fluid and what happens to it?____________________________________________

________________________________________________________________________________________

13.5 CARDIOVASCULAR DISORDERS (P. 256)

• Although the cardiovascular system is very efficient, it is still subject to degenerative disorders.

33. Match the items in the key to the statements that follow.Key artificial pacemaker needed dietary restriction of salt and/or cholesterol donor heart transplant

coronary bypass

Clearing clogged arteries was unsuccessful. a.

Blood pressure is 200/140. b.

Heartbeat is irregular. c.

Congestive heart failure is present. d. 34. Match the items in the key to the phrases that follow.

Key thrombus and embolus atherosclerosis and hypertension varicose veins hemorrhoids

stroke and heart attack a.

varicose veins in rectum b.

weakened valves c.

blood vessels narrowed by plague d.

CHAPTER TEST

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OBJECTIVE QUESTIONS

Do not refer to the text when taking this test.____ 1.Which type of blood vessel allows the exchange

of material between the blood and the tissues?a. arteriesb. arteriolesc. capillariesd. veinse. venules

____ 2.Arteriesa. carry blood away from the heart.b. carry blood toward the heart.c. have valves.d. Both a and b are correct.

____ 3.Which of these vessels have the thinnest walls?a. arteriesb. veinsc. Both are the same.

____ 4.The venae cavaea. carry blood to the right atrium.b. carry blood away from the right atrium.c. join with the aorta.d. have a high blood pressure.

____ 5.The coronary arteries carry blooda. from the aorta to the heart tissues.b. from the heart to the brain.c. directly to the heart from the pulmonary cir-

cuit.d. from the lungs directly to the left atrium.

____ 6.Which of these chambers has the thickest walls?a. right atriumb. right ventriclec. left atriumd. left ventricle

____7. The SA nodea. works only when it receives a nerve impulse.b. is located in the left atrium.c. initiates the heartbeat.d. All of these are correct.

____ 8.What is the function of the heart valves?a. to push bloodb. to prevent backflowc. to stimulate the heartd. to give support to the heart

____9. The first wave (the P wave) of an ECG is due toa. atrial contraction.b. ventricular contraction.c. ventricular relaxation.d. atrial relaxation.

____10.The heart sounds are due toa. blood flowing.b. the closing of the valves.c. the heart muscle contracting.d. blood pressure in the aorta.

____11.Blood flows in veins because ofa. contraction of valves.b. arterial blood pressure.c. capillary blood pressure.d. skeletal muscle contraction.

____12.Systole refers to the contraction of thea. major arteries.b. SA node.c. atria and ventricles.d. major veins.

____13.Blood pressure falls off drastically in the capil-laries because the capillariesa. contain valves.b. become veins.c. have a large cross-sectional area.d. All of these are correct.

____14.The major portion of the cardiovascular systemis called thea. systemic circuit.b. pulmonary circuit.c. hepatic portal circuit.d. coronary circuit.

____15.Blood flowing to the lungs leaves the heart viathe _______________ and returns to the heartvia the _______________.a. aorta; superior vena cavab. superior vena cava; aortac. pulmonary arteries; pulmonary veinsd. aorta; pulmonary veins

16. A heart attack is due to a blockeda. pulmonary artery.b. coronary artery.c. aorta.d. vena cava.

17. Hemoglobina. transports O2.b. transports CO2.c. picks up hydrogen ions.d. all of these

18. Carbon monoxide is poisonous due to the factthat ita. combines more readily with hemoglobin than

oxygen does.b. destroys red blood cells.c. destroys the body’s tissues.d. destroys oxygen.

19. Which of the following characterizes anemia?a. low red blood cell count, low hemoglobin, or bothb. viral infectionc. congenital diseased. All of these are correct.

20. Aged red blood cells are destroyed in thea. red bone marrow.b. lungs.c. lymph nodes.d. spleen and liver.

21. Which of the following white blood cells hasgranules and is phagocytic?a. lymphocyteb. basophilc. monocyted. neutrophil

22. Which of these is not a valid contrast between redblood cells and white blood cells?

red whitea. erythrocyte–leukocyteb. phagocytic–motilec. lacks nucleus–has nucleusd. numerous–less numerous

23. Choose the best description of neutrophils.a. multilobed nuclei, phagocytic, do not take up

stainb. U-shaped nucleus, dark blue after staining,

turn into mast cellsc. bilobed nucleus, red after staining, present

with allergiesd. kidney-shaped nucleus, phagocytic, turn into

macrophages24. Choose the best description of basophils.

a. lobed nuclei, phagocytic, do not take up stainb. U-shaped nucleus, dark blue after staining,

related to mast cellsc. bilobed nucleus, red after staining, present

with allergiesd. kidney-shaped nucleus, phagocytic, turn into

macrophages25. Plasma transports

a. nutrients.b. CO2.c. hormones.d. All of these are correct.

26. Which plasma protein becomes the threads of a clot?a. prothrombinb. thrombinc. prothrombin activatord. fibrinogen

27. Which of these is not a normal function of plasmaproteins?a. maintaining osmotic pressureb. a widely used source of nutrition for the bodyc. fighting infectiond. contributing to blood clotting

28. Plasma isa. the same as tissue fluid.b. the liquid remaining after blood clots.c. the liquid portion of the blood.d. All of these are correct.

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109

29. At a capillarya. oxygen is exchanged for carbon dioxide.b. glucose is exchanged for amino acids.c. water is exchanged for proteins.d. waste material carried in blood is deposited into

tissues.

30. Water reenters capillaries at their venous ends because ofa. active transport from interstitial fluid.b. osmotic pressure of blood drawing fluid from

tissues.

THOUGHT QUESTIONS

Answer in complete sentences.31. How do you think lower osmotic pressure would affect capillary exchange?

32. What do you think would happen to the heartbeat if the SA node did not stimulate the AV node?

Test Results: _______ number correct ÷ 32 = _________ × 100 = _______%

110

STUDY EXERCISES

1. a. heart b. artery c. arterioles d. capillaries e. venulesf. vein 2. a. artery b. vein c. artery d. vein e. capil-lary f. vein 3. The shunting of blood around capillarybeds is possible because each bed has a thoroughfarechannel that allows blood to flow directly from arterioleto venule. Sphincter muscles prevent blood from flowinginto the capillaries. 4. a. vena cava, right atrium, atri-oventricular valve, right ventricle, pulmonary semilunarvalve, pulmonary artery, lungs b. lungs, pulmonary veins,left atrium, atrioventricular valve, left ventricle, aorticsemilunar valve, aorta 5. a. aorta b. superior vena cavac. SA node d. AV node e. right atrium f. atrioventric-ular (tricuspid) valve g. chordae tendineae h. right ven-tricle i. inferior vena cava j. pulmonary artery k. aorticsemilunar valve l. left atrium m. atrioventricular (mi-tral) valve n. septum o. left ventricle 6. The left ven-tricle is thicker-walled than the right ventricle because theleft one must pump blood the greater distance to the en-tire body. The right ventricle only pumps the shorter dis-tance to the lungs. 7. a. systole b. diastole c. diastoled. diastole e. systole f. diastole 8. a. atrioventricularb. ventricles c. semilunar 9. a. SA node b. AV node c.AV node d. AV node 10. a. associated with atrial sys-tole b. associated with ventricular systole c. associatedwith ventricular recovery 11. a. parasympathetic sys-tem b. sympathetic system c. sympathetic systemd. parasympathetic system 12. a. speeds b. speeds13. blood pressure 14. systole and diastole of the left ven-tricle of the heart 15. distance from heart and increasein cross-sectional area of blood vessels 16. skeletalmuscle contraction 17. valves 18. a. pulmonary ar-teries b. pulmonary veins c. iliac vein d. inferior venacava 19. a. mesenteric arteries b. hepatic portal vein c. hepatic vein 20. a. water b. plasma proteins21. a. globulin b. fibrinogen c. albumin d. all plasma

proteins 22. a. erythrocytes b. red bone marrow c. nu-cleus d. hemoglobin e. liver and spleen f. anemia 23. a,d, e, 24. a. leukocytes b. red bone marrow 25. a. largerb. nucleus c. hemoglobin 26. a. lymphocyte b. neu-trophil c. monocyte d. basophil e. eosinophil27 a. leukemia b. white blood cells (leukocytes) 28. a. left-hand side b. prothrombin activator and thrombin c. fib-rin threads 29. a. K b. calcium 30. a. arterial end ofcapillary b. blood pressure c. net pressure out d. os-motic pressure e. water, oxygen, and nutrients f. waterand wastes g. blood pressure h. net pressure in i. osmoticpressure j. tissue fluid. 31. At the arterial end of a cap-illary, blood pressure is higher than osmotic pressure.Therefore water, nutrients, and oxygen leave a capillary.At the venous end of a capillary, osmotic pressure ishigher than blood pressure; therefore water and wastes entera capillary. In this way tissue fluid is refreshed. 32. Thissystem never retrieves all the water that leaves capillar-ies, and excess tissue fluid is picked up by lymphatic ves-sels and returned to the bloodstream. 33. a. coronarybypass b. dietary restriction of salt and/or cholesterolc. artificial pacemaker needed d. donor heart transplant34. a. thrombus and embolus b. hemorrhoids c. varicoseveins d. atherosclerosis and hypertension

CHAPTER TEST

1. c 2. a 3. b 4. a 5. a 6. d 7. c 8. b 9. a10. b 11. d 12. c 13. c 14. a 15. c 16. b17. d 18. a 19. a 20. d 21. d 22. b 23. a24. b 25. d 26. d 27. b 28. c 29. a 30. b31. Tissue fluid would not be returned as efficiently to thevenous end of the capillary. It would remain in the tissuespaces, and edema would result. 32. The ventricleswould not be signaled to contract. Therefore, ventricularsystole would not take place, and oxygenated blood wouldnot effectively flow to the body’s tissues.

ANSWER KEY