human anatomy and physiology
baisc

LEVELS OF ORGANIZATION
The human body is organized into structural and
functional levels of increasing complexity. Each higher
level incorporates the structures and functions of the
previous level, as you will see. We will begin with the
simplest level, which is the chemical level, and proceed
to cells, tissues, organs, and organ systems. All of
the levels of organization are depicted in Fig. 1–1.
CHEMICALS
The chemicals that make up the body may be divided
into two major categories: inorganic and organic.
Inorganic chemicals are usually simple molecules
made of one or two elements other than carbon (with
a few exceptions). Examples of inorganic chemicals are
water (H2O); oxygen (O2); one of the exceptions, carbon
dioxide (CO2); and minerals such as iron (Fe), calcium
(Ca), and sodium (Na). Organic chemicals are
often very complex and always contain the elements
carbon and hydrogen. In this category of organic
chemicals are carbohydrates, fats, proteins, and
nucleic acids. The chemical organization of the body
is the subject of Chapter 2.
CELLS
The smallest living units of structure and function are
cells. There are many different types of human cells,
though they all have certain similarities. Each type of
cell is made of chemicals and carries out specific
chemical reactions. Cell structure and function are
discussed in Chapter 3.
TISSUES
A tissue is a group of cells with similar structure and
function. There are four groups of tissues:
Epithelial tissues—cover or line body surfaces; some
are capable of producing secretions with specific
functions. The outer layer of the skin and sweat
glands are examples of epithelial tissues. Internal
epithelial tissues include the walls of capillaries
(squamous epithelium) and the kidney tubules
(cuboidal epithelium), as shown in Fig. 1–1.
4 Organization and General Plan of the Body
1. Chemical Level
2. Cellular Level
3. Tissue Level
4. Organ Level
5. Organ System
Level
6. Organism Level
Cuboidal epithelium
Squamous epithelium
Smooth muscle
Kidney
Urinary
bladder
Urinary
system
Figure 1–1. Levels of structural organization of the human body, depicted from the
simplest (chemical) to the most complex (organism). The organ system shown here is the
urinary system.
QUESTION: What other organ system seems to work directly with the urinary system?
5
Connective tissues—connect and support parts of
the body; some transport or store materials. Blood,
bone, cartilage, and adipose tissue are examples of
this group.
Muscle tissues—specialized for contraction, which
brings about movement. Our skeletal muscles and
the heart are examples of muscle tissue. In Fig. 1–1,
you see smooth muscle tissue, which is found in
organs such as the urinary bladder and stomach.
Nerve tissue—specialized to generate and transmit
electrochemical impulses that regulate body functions.
The brain and optic nerves are examples of
nerve tissue.
The types of tissues in these four groups, as well as
their specific functions, are the subject of Chapter 4.
ORGANS
An organ is a group of tissues precisely arranged so as
to accomplish specific functions. Examples of organs
are the kidneys, individual bones, the liver, lungs,
and stomach. The kidneys contain several kinds of
epithelial, or surface tissues, for their work of absorption.
The stomach is lined with epithelial tissue that
secretes gastric juice for digestion. Smooth muscle
tissue in the wall of the stomach contracts to mix
food with gastric juice and propel it to the small intestine.
Nerve tissue carries impulses that increase or
decrease the contractions of the stomach (see Box 1–1:
Replacing Tissues and Organs).
ORGAN SYSTEMS
An organ system is a group of organs that all contribute
to a particular function. Examples are the urinary
system, digestive system, and respiratory system.
In Fig. 1–1 you see the urinary system, which consists
of the kidneys, ureters, urinary bladder, and urethra.
These organs all contribute to the formation and
elimination of urine.
As a starting point, Table 1–1 lists the organ systems
of the human body with their general functions,
and some representative organs, and Fig. 1–2 depicts
6 Organization and General Plan of the Body
BOX 1–1 REPLACING TISSUES AND ORGANS
eventually be used to cover a large surface. Other
cells grown in culture include cartilage, bone, pancreas,
and liver. Much research is being done on
liver implants (not transplants), clusters of functional
liver cells grown in a lab. Such implants
would reduce or eliminate the need for human
donors. Tissue engineering is also being used to create
arteries and urinary bladders.
Many artificial replacement parts have also been
developed. These are made of plastic or metal and
are not rejected as foreign by the recipient’s
immune system. Damaged heart valves, for example,
may be replaced by artificial ones, and sections
of arteries may be replaced by tubular grafts made
of synthetic materials. Artificial joints are available
for every joint in the body, as is artificial bone for
reconstructive surgery. Cochlear implants are tiny
instruments that convert sound waves to electrical
impulses the brain can learn to interpret, and have
provided some sense of hearing for people with certain
types of deafness. Work is also progressing on
the use of a featherweight computer chip as an artificial
retina, on devices that help damaged hearts
pump blood more efficiently, and on small, selfcontained
artificial hearts.
Blood transfusions are probably the most familiar
and frequent form of “replacement parts” for people.
Blood is a tissue, and when properly typed and
cross-matched (blood types will be discussed in
Chapter 11) may safely be given to someone with
the same or a compatible blood type.
Organs, however, are much more complex structures.
When a patient receives an organ transplant,
there is always the possibility of rejection (destruction)
of the organ by the recipient’s immune system
(Chapter 14). With the discovery and use of
more effective immune-suppressing medications,
however, the success rate for many types of organ
transplants has increased. Organs that may be transplanted
include corneas, kidneys, the heart, the
liver, and the lungs.
The skin is also an organ, but skin transplanted
from another person will not survive very long.
Several kinds of artificial skin are now available to
temporarily cover large areas of damaged skin.
Patients with severe burns, for example, will eventually
need skin grafts from their own unburned
skin to form permanent new skin over the burn
sites. It is possible to “grow” a patient’s skin in laboratory
culture, so that a small patch of skin may
all of the organ systems. Some organs are part of two
organ systems; the pancreas, for example, is both a
digestive and an endocrine organ, and the diaphragm
is part of both the muscular and respiratory systems.
All of the organ systems make up an individual person.
The balance of this text discusses each system in more
detail.
METABOLISM AND HOMEOSTASIS
Metabolism is a collective noun; it is all of the chemical
reactions and physical processes that take place
within the body. Metabolism includes growing, repairing,
reacting, and reproducing—all the characteristics
of life. The pumping of the heart, the digestion of
food in the stomach, the diffusion of gases in the lungs
and tissues, and the production of energy in each cell
of the body are just a few of the thousands of aspects
of metabolism. Metabolism comes from a Greek word
meaning “change,” and the body is always changing in
visible ways (walking down the street), microscopic
ways (cells dividing in the skin to produce new epidermis),
and submicroscopic or molecular ways (RNA
and enzymes constructing new proteins). A related
concept, metabolic rate, is most often used to mean
the speed at which the body produces energy and heat,
or, put another way, energy production per unit of
time, such as 24 hours. Metabolic rate, therefore, is
one aspect of metabolism.

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As the science and arts of medicine and health care become increasingly complex,
so too does the education of those who pursue careers in nursing and other healthrelated
fields. Human anatomy and physiology is often a first course in many education
programs, and is the basis for so many of the more specialized courses. Teachers
of introductory anatomy and physiology thus take on a special challenge: We must
distill and express the complexities of human structure and function in a simple way,
without losing the essence and meaning of the material. That is the goal of this textbook:
to make this material readily accessible to students with diverse backgrounds
and varying levels of educational preparation.
No prior knowledge of biology or chemistry is assumed, and even the most fundamental
terms are defined thoroughly. Essential aspects of anatomy are presented
clearly and reinforced with excellent illustrations. Essential aspects of physiology are
discussed simply, yet with accuracy and precision. Again, the illustrations complement
the text material and foster comprehension on the part of the student. These illustrations
were prepared especially for students for whom this is a first course in anatomy
and physiology. As you will see, these are images in which detail is readily apparent.
All important parts have been labeled, but the student is not overwhelmed with
unnecessary labels. Illustrations of physiology lead the student step-by-step.
Wherever appropriate, the legends refer students to the text for further description or
explanation. Each illustration also has a question for the student; the illustration questions
in a chapter form an ongoing self-test. (The answers are given in Appendix G.)
The text has three unifying themes: the relationship between physiology and
anatomy, the interrelations among the organ systems, and the relationship of each
organ system to homeostasis. Although each type of cell, tissue, organ, or organ system
is discussed simply and thoroughly in itself, applicable connections are made to
other aspects of the body or to the functioning of the body as a whole. Our goal is to
provide your students with the essentials of anatomy and physiology, and in doing so,
to help give them a solid foundation for their future work, and an appreciation for the
incredible living organism that is the human body.
The sequence of chapters is a very traditional one. Cross-references are used to
remind students of what they have learned from previous chapters. Nevertheless, the
textbook is very flexible, and, following the introductory four chapters, the organ systems
may be covered in almost any order, depending on the needs of your course.
Each chapter is organized from the simple to the more complex, with the anatomy
followed by the physiology. The Instructor’s Guide presents modifications of the topic
sequences that may be used, again depending on the needs of your course. Certain
more advanced topics may be omitted from each chapter without losing the meaning
or flow of the rest of the material, and these are indicated, for each chapter, in the
Instructor’s Guide.
Clinical applications are set apart from the text in boxed inserts. These are often
aspects of pathophysiology that are related to the normal anatomy or physiology in the
text discussion. Each box presents one particular topic and is referenced at the appropriate
point in the text. This material is intended to be an integral part of the chapter
but is set apart for ease of reference and to enable you to include or omit as many of
these topics as you wish. The use of these boxes also enables students to read the text
material without interruption and then to focus on specific aspects of pathophysiology.
A comprehensive list of the boxes appears inside the book’s front and back covers, and
another list at the beginning of each chapter cites the boxes within that chapter.
Tables are utilized as summaries of structure and function, to present a sequence of
events, or additional material that you may choose to include. Each table is referenced
in the text and is intended to facilitate your teaching and to help your students learn.
New terms appear in bold type within the text, and all such terms are fully defined
in an extensive glossary, with phonetic pronunciations. Bold type may also be used for
emphasis whenever one of these terms is used again in a later chapter.
Each chapter begins with a chapter outline and student objectives to prepare the
student for the chapter itself. New terminology and related clinical terms are also
listed, with phonetic pronunciations. Each of these terms is fully defined in the glossary,
with cross-references back to the chapter in which the term is introduced.
At the end of each chapter are a study outline and review questions. The study outline
includes all of the essentials of the chapter in a concise outline form. The review
questions may be assigned as homework, or used by the students as a review or selftest.
Following each question is a page reference in parentheses. This reference cites
the page(s) in the chapter on which the content needed to answer the question correctly
can be found. The answers themselves are included in the Instructor’s Guide.
The questions in the sections titled For Further Thought may be used in a variety of
ways, and the answers are in the Instructor’s Guide.
An important supplementary learning tool for your students is available in the form
of a Student Workbook that accompanies this text. For each chapter in the textbook, the
workbook offers fill-in and matching-column questions, figure-labeling and figurecoloring
exercises, and crossword puzzles based on the chapter’s vocabulary list. Also
included are two comprehensive, multiple-choice chapter tests to provide a thorough
review. All answers are provided at the end of the workbook.
Ancillary materials for the teacher using this text are all on a CD-ROM: a complete
Instructor’s Guide, two computerized test banks, and an Image Ancillary presentation
of the text illustrations. The Instructor’s Guide contains notes on each chapter’s
organization and content (useful for modifying the book to your specific teaching
needs), topics for class discussion, answers to the chapter review questions from the
textbook, and detailed answers to the For Further Thought questions. The multiplechoice
test bank contains more than 2600 questions that have been organized in
relation to the chapter review questions, and further explanation may be found in the
Instructor’s Guide. The fill-in test bank contains more than 2100 questions organized
by textbook chapter. The Image Ancillary presentation contains many of the illustrations
from the textbook, with suggested points for use in classroom lectures.
Suggestions and comments from colleagues are always valuable, and yours would
be greatly appreciated.
Any suggestions that you can provide to help us achieve that goal are most welcome,