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To the Reader
This book was written with the intent of making the subject of and master the essential content for your current as well as fu-
pathophysiology an exciting exploration that relates normal ture needs.
body functioning to the physiologic changes that participate in It is essential for any professional to use and understand the
disease production and occur as a result of disease, as well as vocabulary of his or her profession. Throughout the text, you
the body’s remarkable ability to compensate for these changes. will encounter terms in italics. This is a signal that a word and
Indeed, it is these changes that represent the signs and symp- the ideas associated with it are important to learn. In addition,
toms of disease. two aids are provided to help you expand your vocabulary and
Using a book such as this can be simplified by taking the improve your comprehension of what you are reading: the
time to find what is in the book and how to locate information glossary and the list of prefixes and suffixes.
when it is needed. The table of contents at the beginning of the The glossary contains concise definitions of frequently en-
book provides an overall view of the organization and content countered terms. If you are unsure of the meaning of a term
of the book. It also provides clues as to the relationships among you encounter in your reading, check the glossary in the back
areas of content. For example, the location of the chapter on of the book before proceeding.
neoplasia within the unit on cell function and growth indicates The list of prefixes and suffixes is a tool to help you derive the
that neoplasms are products of altered cell growth. The index, meaning of words you may be unfamiliar with and increase
which appears at the end of the book, can be viewed as a road your vocabulary. Many disciplines establish a vocabulary by
map for locating content. It can be used to quickly locate re- affixing one or more sounds or letters to the beginning or end
lated content in different chapters of the book or to answer of a word or base to form a derivative word. Prefixes are added
questions that come up in other courses. to the beginning of a word or base, and suffixes are added to
the end. If you know the meanings of common prefixes and
suffixes, you can usually derive the meaning of a word, even if
ORGANIZATION you have never encountered it before. A list of prefixes and suf-
fixes common to pathophysiology can be found on the inside
The book is organized into units and chapters. The units iden- covers.
tify broad areas of content, such as alterations in the circulatory
system. The chapters focus on specific areas of content, such as
heart failure and circulatory shock. The chapter outline that ap- BOXES
pears at the beginning of each chapter provides an outline of
the content in the chapter. Icons identify specific content related Boxes are used throughout the text to summarize and high-
light key information. You will encounter two types of boxes:
to infants and children , pregnant women, , and older Key Concept Boxes and Summary Boxes.
adults . One of the ways to approach learning is to focus on the
major ideas or concepts rather than trying to memorize a list
Many of the units have a chapter that contains essential in- of related and unrelated bits of information. As you have
formation about the structures being discussed in the unit. probably already discovered, it is impossible to memorize
These chapters provide the foundation for understanding the everything that is in a particular section or chapter of the
pathophysiology content presented in the subsequent chapters. book. First, your brain has a difficult time trying to figure out
where to store all the different bits of information. Secondly,
your brain doesn’t know how to retrieve the information
READING AND LEARNING AIDS when you need it. Thirdly, memorized lists of content can
seldom be applied directly to an actual clinical situation.
In an ever-expanding world of information you will not be able
The Key Concept Boxes guide you in identifying the major
to read, let alone remember, everything that is in this book, or
ideas or concepts that form the foundation for truly under-
in any book, for that matter. With this in mind, we have devel- standing the major areas of content. When you understand
oped a number of special features that will help you focus on
xiii
xiv To the Reader
the concepts in the Key Concept boxes, you will have a TABLES AND CHARTS
framework for remembering and using all of the facts given
in the text. Tables and charts are designed to present complex infor-
mation in a format that makes it more meaningful and eas-
KEY CONCEPTS
COMPONENTS OF THE IMMUNE SYSTEM
ier to remember. Tables have two or more columns, and are
■ The immune system consists of immune cells; the
often used for the purpose of comparing or contrasting
central immune structures (the bone marrow and information. Charts have one column and are used to sum-
thymus), where immune cells are produced and ma-
ture; and the peripheral immune structures (lymph marize information.
nodes, spleen, and other accessory structures),
where the immune cells interact with antigen. TABLE 6-5 Manifestations of Hypokalemia and Hyperkalemia
■ The immune cells consist of the lymphocytes (T and Hypokalemia Hyperkalemia
B lymphocytes), which are the primary cells of the
immune system, and the accessory cells such as the Laboratory Values Laboratory Values
macrophages, which aid in processing and presenta- Serum potassium <3.5 mEq/L Serum potassium >5.0 mEq/L
tion of antigens to the lymphocytes. Thirst and Urine
■ Cytokines are molecules that form a communication Increased thirst
Inability to concentrate urine with polyuria and
link between immune cells and other tissues and
urine with low specific gravity
organs of the body.
Effects of Changes in Membrane Potentials Effects of Changes in Membrane Potentials
■ Recognition of self from nonself by the immune cells in Neural and Muscle Function on Neural and Muscle Function
depends on a system of MHC membrane molecules Gastrointestinal Gastrointestinal
that differentiate viral-infected and abnormal cells Anorexia, nausea, vomiting Nausea, vomiting
from normal cells (MHC I) and identify immune cells Abdominal distention Intestinal cramps
from other types of cells (MHC II). Paralytic ileus (severe hypokalemia) Diarrhea
Neuromuscular Neuromuscular
Muscle weakness, flabbiness, fatigue Weakness, dizziness
Muscle cramps and tenderness Muscle cramps
The Summary Boxes at the end of each section provide a re- Paresthesias Paresthesias
Paralysis (severe hypokalemia) Paralysis (severe hyperkalemia)
view of the main content that has been covered. Use the sum- Central Nervous System Cardiovascular
maries to assure that you have covered and understand what Confusion, depression
Cardiovascular
Electrocardiogram changes
Risk of cardiac arrest with severe hyperkalemia
you have read. Postural hypotension
Predisposition to digitalis toxicity
Electrocardiogram changes
In summary, heart failure occurs when the heart fails to Cardiac dysrhythmias
pump sufficient blood to meet the metabolic needs of body Acid-Base Balance
tissues. The physiology of heart failure reflects an interplay Metabolic alkalosis
between a decrease in cardiac output that accompanies im-
paired function of the failing heart and the compensatory
mechanisms designed to preserve the cardiac reserve.
Compensatory mechanisms that contribute to maintenance CHART 5-2 TNM Classification System
of the cardiac reserve include the Frank-Starling mechanism, T (tumor)
sympathetic nervous system responses, the renin-angiotensin-
aldosterone mechanism, and myocardial hypertrophy. In the Tx Tumor cannot be adequately assessed
failing heart, early decreases in cardiac function may go un- T0 No evidence of primary tumor
noticed because these compensatory mechanisms maintain Tis Carcinoma in situ
the cardiac output. This is called compensated heart failure. T1–4 Progressive increase in tumor size or involvement
Unfortunately, the mechanisms were not intended for long- N (nodes)
term use, and in severe and prolonged heart failure, the
compensatory mechanisms no longer are effective and fur- Nx Regional lymph nodes cannot be assessed
ther impair cardiac function. N0 No evidence of regional node metastasis
Heart failure may be described as high-output or low-out- N 1–3 Increasing involvement of regional lymph nodes
put failure, systolic or diastolic failure, and right-sided or left- M (metastasis)
sided failure. With high-output failure, the function of the
heart may be supernormal but inadequate because of exces- Mx Not assessed
sive metabolic needs, and low-output failure is caused by M0 No distant metastasis
disorders that impair the pumping ability of the heart. With M1 Distant metastasis present, specify sites
systolic dysfunction, there is impaired ejection of blood from
the heart during systole; with diastolic dysfunction, there is
impaired filling of the heart during diastole. Right-sided fail-
ure is characterized by congestion in the peripheral circula-
tion, and left-sided failure by congestion in the pulmonary
circulation.
The manifestations of heart failure include edema, noc-
turia, fatigue and impaired exercise tolerance, cyanosis, signs
ILLUSTRATIONS
of increased sympathetic nervous system activity, and im-
paired gastrointestinal function and malnutrition. In right- The full-color illustrations will help you to build your own
sided failure, there is dependent edema of the lower parts of
the body, engorgement of the liver, and ascites. In left-sided mental image of the content that is being presented. Each
failure, shortness of breath and chronic, nonproductive
cough are common.
drawing has been developed to fully support and build upon
Acute pulmonary edema is a life-threatening condition in the ideas in the text. Some illustrations are used to help you
which the accumulation of fluid in the interstitium of the
lung and alveoli interferes with lung expansion and gas ex- picture the complex interactions of the multiple phenomena
change. It is characterized by extreme breathlessness, crack-
les, frothy sputum, cyanosis, and signs of hypoxemia. In car-
that are involved in the development of a particular disease;
diogenic shock, there is failure to eject blood from the heart, others can help you to visualize normal function or under-
hypotension, inadequate cardiac output, and impaired per-
fusion of peripheral tissues. Mechanical support devices, in- stand the mechanisms whereby the disease processes exert
cluding the intra-aortic balloon pump (for acute failure) and
the VAD, sustain life in persons with severe heart failure.
their effects. In addition, photographs of pathologic processes
Heart transplantation remains the treatment of choice for and lesions provide a realistic view of selected pathologic
many persons with end-stage heart failure.
processes and lesions.
To the Reader xv
Inhalation of
down your answers to the review questions at the end of the
tubercle bacillus chapter. If you are unable to answer a question, reread the rel-
evant section in the chapter. In addition, you will find multiple-
choice questions on the back-of-the-book CD-ROM and on the
Connection site (http://connection.LWW.com/go/porth). Use
these quizzes to test yourself as well.
Primary Secondary
tuberculosis tuberculosis
APPENDICES
Cell-mediated Development of
hypersensitivity cell-mediated Reinfection
response immunity
Your book contains two appendices. Appendix A, “Laboratory
Granulomatous
Values,” provides rapid access to normal values for many lab-
inflammatory
response
Positive skin
test oratory tests, as well as a description of the prefixes, symbols,
and factors (e.g., micro, µ, 10−6) used for describing these val-
Ghon's
Progressive ues. Knowledge of normal values can help you to put abnor-
or disseminated
complex
tuberculosis mal values in context. Appendix B, “Weblinks,” is provided to
help you in obtaining additional information on topics that are
Healed dormant Reactivated of interest to you. The websites in Appendix B will also help
lesion tuberculosis
you to keep abreast of new information that is constantly
■ FIGURE 20-2 ■ Pathogenesis of TB Infection
evolving. For your convenience, these weblinks are also found
on the book’s Connection site.
We hope that this guide has given you a clear picture of how
to use this book. Good luck and enjoy the journey!
MATERIALS FOR REVIEW
Several features have been built into the text to help you verify
your understanding of the material that you have just read.
After you have finished reading and studying the chapter, write
