Table 1.1
System(s)
Function
Integum entary and lym phatic system s
Protect your body from disease
Integum entary and nervous system s
Se n se the outside and process
inform ation
Skeletal and m uscular system s
Move
D igestive system
Eat and get nutrients from food
Respiratory and cardiovascular s y s -
tem s
Exchange gases with the air and
body tissu es
Card iovascu lar system
Distribute nutrients from food
and gases throughout you r body
D igestive and urinary system s
Elim inate w astes
Integum entary, cardiovascular, and
endocrine system s
Regulate body tem perature
N ervous and endocrine system s
Coordinate body functions
Reproductive and endocrine system s
Reproduce
As you proceed through this book, you will
learn the anatomy and function of each system
separately, but keep in mind that they all work
together in a normally functioning individual
(
Table 1.1
).
C O N C EP T C H EC K
1.
What
is the difference between anato-
my and physiology?
2.
What
are the levels of organization of
the body, from lowest to highest?
3.
Which
body system helps distribute
oxygen and nutrients to cells and tis-
sues, while removing carbon dioxide
and wastes?
All Living Organisms Carry Out
Common Life Processes
LEARNING OBJECTIVES
1.
Outline
the important life processes of humans.
2.
Distinguish
between negative and positive
feedback systems.
3.
Define
homeostasis
and describe how it is af-
fected by aging and disease.
ike any other organism, humans must carry
out certain life processes and maintain a
constant internal environment. Failure to do
these things can lead to disease and death.
Let’s look at life processes.
Life Processes Include Every Function
Necessary to Sustain Life
Your organ systems enable your body to carry out various pro-
cesses (
Figure 1.3
). Their functions include the following:
1.
M etabolism
(me-TAB-o-lizm)
is
all
the
chemical
processes that occur in the body.
2.
R esponsiveness
is the ability to detect and respond
to changes that occur both inside and outside the
body. Different cells in the body detect different types
of changes and respond in characteristic ways. If
you touch a hot pot, nerve cells sense the change or
possible damage, make electrical signals called nerve
impulses, and send these impulses to muscle cells,
which contract to move your hand away, sometimes
even before you are aware of the heat.
3.
M ovem ent
includes
motion
of
the
whole
body,
individual organs, single cells, and even tiny structures
inside cells.
4.
G row th
is an increase in body size due to an increase
in the size of existing cells, the number of cells, or the
amount of material surrounding cells.
5.
D iffe re n tia tio n
(dif'-er-en-she-A-shun) is the process
that unspecialized cells undergo to become specialized
cells. Specialized cells differ in structure and function
from the unspecialized cells that gave rise to them.
6.
R e p ro d u ctio n
(re-pro-DUK-shun) refers to either the
production of a new individual or the formation of new
cells for growth, repair, or replacement.
Not all of these processes continually occur in cells through-
out the body. However, when life processes cease to occur
properly, cell death may occur. When cell death is extensive
and leads to organ failure, the organism usually dies.
6 CHAPTER 1
Organization of the Human Body
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