Cardiovascular Physiology
425
SECTION E CLINICAL TERMS
SECTION E REVIEW QUESTIONS
1. Draw a fl ow diagram illustrating the refl ex compensation for
hemorrhage.
2. What happens to plasma volume and interstitial fl
uid volume
following a hemorrhage?
3. What causes hypotension during a severe allergic response?
4. How does gravity infl uence effective blood volume?
5. Describe the role of the skeletal muscle pump in decreasing
capillary fi ltration.
6. List the directional changes that occur during exercise for all
relevant cardiovascular variables. What are the specifi c efferent
mechanisms that bring about these changes?
7. What factors enhance venous return during exercise?
8. Diagram the control of autonomic outfl ow during exercise.
9. What is the limiting cardiovascular factor in endurance exercise?
10. What changes in cardiac function occur at rest and during
exercise as a result of endurance training?
11. What is the abnormality in most cases of established hypertension?
12. State how fl uid retention can help restore stroke volume in
heart failure.
13. How does heart failure lead to edema in the pulmonary and
systemic vascular beds?
14. Name the major risk factors for atherosclerosis.
15. Describe changes in lifestyle that may help prevent coronary
artery disease.
16. List some ways that coronary artery disease can be treated.
angina pectoris
422
angiotensin-converting enzyme
(ACE) inhibitors
420
atherosclerosis
422
automatic electronic defi
brillator
(AED)
422
beta-adrenergic receptor
blocker
421
calcium channel blocker
420
cardiac inotropic drug
421
cardiogenic shock
414
cardiopulmonary resuscitation
(CPR)
422
congestive heart failure
419
coronary artery disease
422
coronary balloon
angioplasty
424
coronary bypass
424
coronary stent
424
coronary thrombosis
422
defi
brillation
422
diastolic dysfunction
420
digitalis
421
diuretic
419
embolism
424
embolus
424
folic acid
422
heart attack
422
heart failure
419
homocysteine
422
hypertension
419
hypotension
413
hypovolemic shock
414
ischemia
422
left ventricular hypertrophy
419
low-resistance shock
414
myocardial infarction
422
nitroglycerin
423
primary hypertension
419
pulmonary edema
421
renal hypertension
419
shock
414
stroke
419
systolic dysfunction
420
transient ischemic attack
(TIA)
424
vasodilator drug
421
vasovagal syncope
414
ventricular fi
brillation
422
SECTION F
Blood and Hemostasis
Blood was defi ned earlier as a mixture of cellular components
suspended in a fl uid called plasma. In this section we will take
a more detailed look at blood cells and plasma, and then dis-
cuss the complex mechanisms that prevent blood loss follow-
ing injury.
Plasma
Plasma consists of a large number of organic and inorganic sub-
stances dissolved in water. Inside this book’s back cover are listed
substances dissolved in plasma, and their typical concentrations.
The
plasma proteins
constitute most of the p
lasma
solutes, by weight. Their role in exerting an osmotic pressure
that favors the absorption of extracellular fl
uid into capillaries
was described earlier. They can be classifi ed into three broad
groups: the
albumins,
the
globulins,
and
brinogen.
The
fi rst two have many overlapping functions, which are dis-
cussed in relevant sections throughout the book. Fibrinogen
functions in clotting, discussed in detail in the latter part
of this section.
Serum
is plasma with fi brinogen and other
proteins involved in clotting removed as a result of clotting.
The albumins are the most abundant of the three plasma
protein groups and are synthesized by the liver. Cells nor-
mally do not take up plasma proteins; cells use plasma amino
acids, not plasma proteins, to make their own proteins. Thus,
plasma proteins must be viewed differently from most of the
other organic constituents of plasma, which use the plasma as
a medium for transport to and from cells. In contrast, most
plasma proteins perform their functions in the plasma itself or
in the interstitial fl
uid.
In addition to the organic solutes, including proteins,
nutrients, metabolic waste products, and hormones, plasma
contains a variety of mineral electrolytes. These ions contrib-
ute much less to the
weight
of plasma than do the proteins,
but in most cases they have much higher
molar concentrations.
This is because molarity is a measure not of weight, but of
number of molecules per unit volume. Thus, there are many
more ions than protein molecules, but the protein molecules
are so large that a very small number of them greatly out-
weighs the much larger number of ions.
The Blood Cells
Erythrocytes
The major functions of erythrocytes are to carry oxygen taken
in by the lungs and carbon dioxide produced by the cells.
Erythrocytes contain large amounts of the protein
hemoglo-
bin
with which oxygen and, to a lesser extent, carbon diox-
ide reversibly combine. Oxygen binds to iron atoms (Fe
2+
) in
the hemoglobin molecules. The average concentration of
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