C H A P T E R 7
Introduction to cell physiology
79
■■
Channels or pores in the cell membrane allow for
easier movement of specific substances needed by the
cell for normal functioning.
■■
Mitochondria are rod-shaped organelles that produce
energy in the form of ATP for use by cells.
■■
Ribosomes are sites of protein production within the
cell cytoplasm. The specific proteins produced by
a cell are determined by the genetic material within
the cell nucleus.
■■
The Golgi apparatus packages particular substances
for removal from the cell (e.g. neurotransmitters,
hormones).
■■
Lysosomes are packets of digestive enzymes located
in the cell cytoplasm. These enzymes are responsible
for destroying injured or non-functioning parts of the
cell and for promoting cellular disintegration when
the cell dies.
■■
Endocytosis is the process of moving substances into
a cell by extending the cell membrane around the
substance and engulfing it. Pinocytosis refers to the
engulfing of necessary materials, and phagocytosis
refers to the engulfing and destroying of bacteria or
other proteins by white blood cells.
■■
Exocytosis is the process of removing substances
from a cell by moving them towards the cell
membrane and then changing the cell membrane
to allow passage of the substance out of the cell.
■■
Cells maintain homeostasis by regulating the
movement of solutes and water into and out of
the cell.
■■
Diffusion, which does not require energy, is
the movement of solutes from a region of high
concentration to a region of lower concentration
across a concentration gradient.
■■
Osmosis, which, like diffusion, does not require
energy, is the movement of water from an area low
in solutes to an area high in solutes. Osmosis exerts
a pressure against the cell membrane that is called
osmotic pressure.
■■
Active transport, an energy-requiring process, is
the movement of particular substances against a
concentration gradient. Active transport is important
in maintaining cell homeostasis.
■■
Cells replicate at differing rates, depending on the
genetic programming of the cell. All cells go through
a life cycle consisting of the following phases: G
0
,
the resting phase; G
1
, which involves the production
of proteins for DNA synthesis; S, which involves the
synthesis of DNA; G
2
, which involves the manufacture
of the materials needed for mitotic spindle production;
and M, the mitotic phase, in which the cell splits to
form two identical daughter cells.
■■
Chemotherapeutic drugs act on cells to cause cell
death or alteration. All properties of the drug that
affect cells should be considered when administering
a chemotherapeutic agent.
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ONLINE RESOURCES
An extensive range of additional resources to enhance teaching
and learning and to facilitate understanding of this chapter may
be found online at the text’s accompanying website, located on
thePoint at
These include Watch and
Learn videos, Concepts in Action animations, journal articles,
review questions, case studies, discussion topics and quizzes.
WEB LINKS
Healthcare providers and students may want to consult
the following Internet source:
Information on cell structure, properties and division.
BIBLIOGRAPHY
Alberts, B. (2008).
Molecular Biology of the Cell
(5th edn).
New York: Garland Science.
Cartwright, K. (2007). Cell markers.
Australian Prescriber, 30(5)
,
128–129.
Cooper, G. & Hausman, R. (2013).
The Cell: A Molecular
Approach
(6th edn). Sunderland MA: Sinauer Associates.
Goodman, L. S., Brunton, L. L., Chabner, B. & Knollmann, B. C.
(2011).
Goodman and Gilman’s Pharmacological Basis of
Therapeutics
(12th edn). New York: McGraw-Hill.
Guyton, A. & Hall, J. (2011).
Textbook of Medical Physiology
(12th edn)
.
Philadelphia: Saunders Elsevier.
Landowne, D. (2006).
Cell Physiology.
New York: McGraw-Hill.
Lodish, H. F. (2013).
Molecular Cell Biology
(7th edn). New York:
W. H. Freeman.
Morgan, D. (2007).
The Cell Cycle: Principles of Control
. London:
New Science Press.
Nair, M. & Peate, I. (2013).
Fundamentals of Applied
Pathophysiology: An Essential Guide for Nursing and
Healthcare Students
(2nd edn). Ames, Iowa: Wiley-Blackwell.
Porth, C. M. (2011).
Essentials of Pathophysiology: Concepts
of Altered Health States
(3rd edn). Philadelphia: Lippincott
Williams & Wilkins.
Porth, C. M. (2009).
Pathophysiology: Concepts of Altered Health
States
(8th edn). Philadelphia: Lippincott Williams & Wilkins.
Sherwood, L. (2013).
Human Physiology from Cells to Systems
(8th edn)
.
Belmont CA: Brooks Cole Cengage Learning.
