This chapter discusses cardiac muscle (4.3) and the

junctions between cardiac muscle cells (4.6).

Blood vessels are built from layers of epithelium, connective

tissue, and smooth muscle (4.1–4.3).

Lipoproteins and cholesterol (2.10, 2.12) are two important

factors in our discussion of cardiovascular health.

Key ConCepts

LinKs to earLier ConCepts

Circulating Blood

The cardiovascular system consists

of a pump—the heart—and blood

vessels that carry pumped blood and

substances in it throughout the body.

S e c t i o n 7.1

Top and second from top: © Cengage Learning; Bottom two: Biophoto

Associates/Science Source

Pumping Blood

The heart’s pumping action drives

blood under pressure through two

circuits—one to the lungs and one

to other body regions. Sections

7. 2 –7. 5

Disorders of the

Cardiovascular System

S e c t i o n s 7. 8 –7. 9

Every day in the United States, in roughly 1,000 people,

the heart suddenly stops pumping blood. About half the cases of this

sudden cardiac arrest occur in people under 40 and often are due

to inborn heart disorders. In older people, heart attack is a common

culprit. Regardless, in nearly 90 percent of cases sudden cardiac

arrest is fatal. Blood carries oxygen, and when the flow abruptly

stops, oxygen-deprived brain cells begin to die unless the heart

can be restarted. Later in this chapter you’ll learn about emergency

procedures that can save the lives of cardiac arrest victims. First,

however, we examine the normal functioning of the cardiovascular

system—the heart and blood vessels that together perform the vital

function of circulating blood throughout the body.

CirCuLation: the heart

and bLood vesseLs

7

121

homeostasis preview

The cardiovascular system delivers oxygen, nutrients, hormones,

and other substances to body cells. It carries away wastes and

substances cells produce. Flowing blood also carries excess

heat to the body surface.

Blood vessels

Blood vessels, including arteries,

arterioles, capillaries, venules, and

veins, are specialized for different

blood transport functions. Sections

7. 6 –7.7

COnnECTiOnS:

The Cardiovascular System

and Blood in Homeostasis

S e c t i o n 7.11

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