Assess What You Learned
14. Which chamber generates the highest pressure during systole?
a. Right atrium
b. Right ventricle
c. Left atrium
d. Left ventricle
15. Fill in the blanks: The first heart sound is called _ _ _ __
valves.
and it is caused by the closing of the
It occurs at the beginning of the
phase
of the cardiac cycle. The second heart sound is called _ _ _ __
valves.
and it is caused by the closing of the
It occurs at the beginning of the
phase of the
cardiac cycle.
16. Cardiac output is equal to:
a. end-diastolic volume minus end-systolic volume.
b. heart rate multiplied by stroke volume.
c. stroke volume divided by end-diastolic volume.
d. heart rate multiplied by preload.
17. Fill in the blanks: An increase in preload causes a/an
- - - - - - in stroke vol ume in accordance with the
- - - - - - law. An increase in afterload causes a/an
______ in stroke vol ume. An increase in contractility
causes a/an - - - - - - in stroke vol ume.
18. Which of the following statements is false?
a. The sympathetic nervous system releases epinephrine
and norepinephrine, which are positive chronotropic and
inotropic agents.
b. The endocrine system regulates cardiac output through
chronotropic and inotropic hormones and through hormones
that regulate water balance.
c. The parasympathetic nervous system releases acetylcholine
and epinephrine, which are strongly negative inotropic
agents.
d. Factors such as electrolyte concentrations, body temperature,
and age all affect cardiac output.
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a. Which ventricle is thicker-walled, and why?
b. Considering your answer to part (a), predict the potential
effects of this birth defect.
2. Predict which would be more damaging to long-term survival:
a blood clot lodged in the right coronary artery or one in the
left coronary artery. Explain.
3. When the SA node doesn't function properly, the AV node
takes over pacing the heart and produces what is known as a
junctional rhythm. Explain why we don't see P waves on the
ECG of an individual with such a rhythm.
4. Common findings in heart failure are fluid retention by the
kidneys and stimulation of the heart by the sympathetic
nervous system. How would both of these findings help the
body to compensate for the failing heart?
LEVEL 3 Apply Your Knowledge
PART A: Application and Analysis
1. You are an athletic trainer who is working with someone
planning to run a marathon. Your trainee tells you to give him a
workout that will make his heart "beat faster than ever before."
What do you tell him about the effects of too rapid a heart rate?
2. A newer drug, ivabradine, lowers the heart rate by blocking
the nonselective HCN cation channels. Why would this action
decrease the heart rate? Would this drug have an effect on
pacemaker cells, contractile cells, or both? Explain.
3. Mr. Watson has been diagnosed with mitral insuffic iency, or
a malfunctioning mitral valve, which causes the valve to not
close proper Iy. Predict the signs and symptoms you might
expect from a disease of this valve. What would happen to the
patient's stroke volume and cardiac output? Explain. What
might help improve his cardiac output?
PART B: Make the Connection
LEVEL 2 Check Your Understanding
1. A birth defect called transposition ofgreat vessels results in
the pulmonary trunk emanating from the left ventricle and the
aorta stemming from the right ventricle.
4. An experimental toxin makes the refractory period of cardiac
muscle cells equal in length to that of skeletal muscle fibers.
Predict the consequences of this toxin. (Connects to Chapter JO)
See answers in Appendix A.
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
Overview of Arteries
and Veins
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e now tum our attention to the second portion of the cardiovascular system:
Physiology of Blood
Flow
chur; vascul- = "vessel"). The vasculature of one individual consists of
Maintenance of
Blood Pressure
Capillaries and
Tissue Perfusion
Capillary Pressures
and Water
Movement
Anatomy of the
Systemic Arteries
Anatomy of the
Systemic Veins
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the blood vessels, collectively called the vasculatur e (VASS-kyoo-lal1billions of blood vessels that transport blood to the tissues, \Vhere gases, nutrients, and
wastes are exchanged, and then transport it back to the heart. If these blood vessels were
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situated end to e nd, they \Vould measure over 60,000 1niles long. But blood vessels are
not 1nerely the "pipes" of the cardiovascular syste1n . They also regulate blood flo\v to
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tissues, control blood pressure, and secrete a variety of che1nicals.
In the heart chapter, \Ve discussed the two circuits that carry blood through the
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body: the pulmonary circuit, \Vhich transports blood between the heart and the lungs;
and the systemic circuit, \Vhich transports blood between the heart and the rest of the
body (see Chapter 17). Here we cover pri1narily the syste1nic circuit, as the pulmonary
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Putti ng It All Together:
The Big Picture of
Blood Vessel
Anatomy
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circuit is discussed \vith the respiratory system (see Chapter 21 ). The first part of this
chapter (Modules 18.1 through 18.5) explores the basic st:Jucture and function of the
different types of blood vessels; the physiology of blood pressure and circulation; and
the physiology of gas, nutrient, and waste exchange. In the second part (Modules 18.6
through 18.8), \Ve exrunine the anatomy of the vessels that make up the systemic circuit.
18.1
Overview of Arteries and Veins
Learning Outcomes
For practice applying concepts to
a clinical scenario, check out the
Running Case Study for this chapter
@
Mastering Anatomy & Physiology
1. Com pa re and contrast the s tructures of a rte ries and ve ins, a nd of a rterioles and
ve nules.
2. Define vascular a nas tomosis, and expla in the s ignifica nce of anas tomoses.
As you read about in the heart chapter, the pulmonary and systemic circuits are composed
of three ki nds of blood vessels- arteries, capillaries, and veins (revisit Figure 17 .8):
Computer-generated image: Blood vessels
are tubular organs that distribute blood
throughout the body.
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• Ar teries are the distribution syste,n of the vasculature. Arteries are vessels
that travel away from the heart, branching into vessels of progressively smaller
diameter. Recall that arteries in the pulmonary circuit carry deoxygenated blood,
whereas those in the syste1nic circuit carry oxygenated blood.