140 Chapter 7
- Heavy smokers often develop abnormally high blood
pressure. The nicotine in tobacco is a potent vasocon-
strictor. Explain the connection between these two facts,
including what kind of blood vessels are likely affected. - Before antibiotics were available, it wasn’t uncommon for
people in the United States (and elsewhere) to develop
rheumatic fever. The infection can trigger an inflammation
that ultimately damages valves in the heart. How must
this disease affect the heart’s functioning? What kinds of
symptoms would arise as a result? - Several years ago the deaths of several airline travelers led
to warnings about “economy-class syndrome.” The idea
is that economy-class passengers don’t have as much leg
room as passengers in more expensive seats, so they are
more likely to sit essentially motionless for long periods
on flights—conditions that may allow blood to pool and
clots to form in the legs. This condition is called deep-vein
thrombosis, or DVT. Given what you know about blood
flow in the veins, explain why periodically getting up and
moving around in the plane’s cabin during a long flight
may lower the risk that a clot will form.
You may remember from
Section 7.8 that the signs of
heart attack differ in males
and females. New research
suggests that gender
differences many also apply
to diagnosing heart attacks in
the first place. Researchers at
the Cardiac and Vascular Institute at New York University/
Langone studied a group of fifty women who all had suffered
heart attacks, even though 38 percent of the patients did not
have coronary arteries seriously clogged by atherosclerotic
plaques. Because imaging methods (called angiography) didn’t
reveal obvious clogs, affected women were initially told they
hadn’t had a heart attack at all. The NYU study discovered
that the heart attacks were real and had been triggered when
a relatively small plaque had suddenly ruptured or become
disrupted in some other way, causing a major blockage. The
research team hopes these findings will spur earlier diagnosis
of heart attack in women whose angiograms appear normal,
but who report heart attack symptoms. Then such patients can
receive medications, such as statins, that can help avert future
heart attacks.your Future
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