Critical and Creative Thinking Questions
1. Juan is having arrhythmias and must have surgery to implant
a pacemaker. A pacemaker produces an “artificial" electrical
stimulus of muscle. Explain how the heart conducts electric-
ity, what an arrhythmia is, and how a pacemaker might help a
patient with an arrhythmia.
2. Anita had surgery in her neck. During the procedure, the sen-
sory nerve from the baroreceptor was damaged. Now, every
time Anita stands up, she faints momentarily. Explain what has
happened to her and why she faints.
3. The Millers' baby was born with a hole in the interventricular
septum (see Figure 11.4a). The baby has a blue skin color.
Explain what's going on in this baby's heart to produce these
symptoms and how this might be corrected.
4. Kim's doctor has prescribed a class of drugs called angioten-
sin-converting enzyme (ACE) inhibitors to treat her hyperten-
sion. ACE is used during the formation of angiotensin II (AII).
How would ACE inhibitors help to lower blood pressure?
5. A cardiologist notices that the QRS complex of Cheryl's EKG
is occasionally “missing" from the EKG
pattern. What does
the QRS complex represent, and what could be causing this
unusual EKG
pattern?
Think Critic.lly»
Patients who experience chest pain and shortness of
breath during exercise stress tests m ay be at risk for coronary artery
disease. W hat do you think is happening to the blood flow through
the heart that may cause such sym ptom s?
What is happening in this picture?
In adults of middle age and older, a heart attack or myocar-
dial infarction typically occurs because a blood clot lodges in
an artery of the heart already narrowed by atherosclerosis.
During exercise, heart rate and blood pressure increase. Un-
der this stress, an unstable plaque may rupture, stimulating
the clotting process as the body tries to repair the damaged
artery. Exercise stress tests are often performed to help diag-
nose coronary artery disease.
Self-Test
(Check your answers in Appendix C.)
1. A patient comes into the ER
with a rapid pulse, mental disori-
entation, and cold, pale, sweaty skin. The patient is suffering
from______.
a. heart attack
c. shock
b. stroke
d. atherosclerosis
2. Which label indicates the chamber of the heart that pumps
blood to the body?
a.
A
b. E
c. B
d. D
3. What is the function of the part of the heart that is labeled A?
a. receives oxygenated blood from the lungs
b. pumps deoxygenated blood to the lungs
c. receives deoxygenated blood from the body
d. pumps oxygenated blood to the body
Use this figure to answer questions 2-5.
< \
I
A
C
B
D
F
H
E
G
340
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