CHARACTERISTICS OF THE LIVING ORGNISUM

• Define the important life processes of the human body.

• Define homeostasis and explain its relationship to

of these sciences.

Two branches of science—anatomy and physiology—provide

the foundation for understanding the body’s parts and functions.

Anatomy

(a-NAT-o¯-me¯; ana- up; -tomy process of cutting)

is the science of body

structures and the relationships among

them. It was first studied by

dissection (dis-SEK-shun; dis-

apart;

-section act of cutting), the careful cutting apart of body

structures to study their relationships. Today, a variety of imaging

techniques (see

Table 1.3 on page 21) also contribute to the

advancement of anatomical knowledge. Whereas anatomy deals

with structures of the body,

physiology (fiz -e¯-OL-o¯-je¯; physio-

nature;

-logy study of) is the science of body functions—how

the body parts work.

Table 1.1 describes several subspecialties

of anatomy and physiology.

Because structure and function are so closely related, you will

learn about the human body by studying its anatomy and

physiology together. The structure of a part of the body allows

performance of certain functions. For example, the bones of the

skull join tightly to form a rigid case that protects the brain. The

bones of the fingers are more loosely joined to allow a variety of

movements. The walls of the air sacs in the lungs are very thin,

AN INTRODUCTION TO HUMAN BODY

T H E H U M A N B O D Y A N D H O M E O S T A S I S

Humans have many ways to maintain homeostasis, the state of

relative stability of the body’s internal environment. Disruptions

to homeostasis often set in motion corrective

cycles, called feedback systems, that help restore

the conditions needed for health and life.

•

1

Our fascinating journey through the human

body begins with an overview of the meanings                                         

of anatomy and physiology, followed

by a discussion of the organization of the

human body and the properties that it

shares with all living things. Next, you will discover

how the body regulates its own internal environment;

this unceasing process, called homeostasis, is a major

theme in every chapter of this book. Finally, we introduce

the basic vocabulary that will help you speak

about the body in a way that is understood by scientists  

and health-care professionals alike.                                     

AN INTRODUCTION TO HUMAN BODY

T H E H U M A N B O D Y A N D H O M E O S T A S I S

Humans have many ways to maintain homeostasis, the state of

relative stability of the body’s internal environment. Disruptions

to homeostasis often set in motion corrective

cycles, called feedback systems, that help restore

the conditions needed for health and life.

•

1

Our fascinating journey through the human

body begins with an overview of the meanings                                         

of anatomy and physiology, followed

by a discussion of the organization of the

human body and the properties that it

shares with all living things. Next, you will discover

how the body regulates its own internal environment;

this unceasing process, called homeostasis, is a major

theme in every chapter of this book. Finally, we introduce

the basic vocabulary that will help you speak

about the body in a way that is understood by scientists  

and health-care professionals alike.                                     

AN INTRODUCTION TO HUMAN BODY

T H E H U M A N B O D Y A N D H O M E O S T A S I S