Berne & Levy - Physiology-Elsevier 8th (2023) pdf
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Editors :
Bruce M. Koeppen, MD, PhD
Dean Emeritus
Frank H. Netter, MD School of Medicine,
Quinnipiac University
Hamden, Connecticut
United States
Bruce A. Stanton, PhD
Andrew C. Vail Professor
Microbiology and Immunology
Geisel School of Medicine at Dartmouth
Hanover, New Hampshire
United States
Associate Editors
Julianne M. Hall, PhD
Professor of Medical Sciences
Frank H. Netter, MD School of Medicine
Quinnipiac University
Hamden, Connecticut
United States
Agnieszka Swiatecka-Urban, MD
Professor of Pediatrics
Division Head of Pediatric Nephrology
University of Virginia
Charlottesvile, Virginia
United States
Pages: 1570
- Language: English
- Format: PDF
- Size : 37.1 MB
Contents:
. Cover Image
. Title Page
. Copyright
Dedication
. Section Authors
. Preface
Note to
. Instructors
. Table of Contents
Preface
We are pleased that the following section authors have continued as members of the eighth edition team:
Dr. James Watras (muscle), Dr. Withrow Gil Wier (cardiovascular system), Drs. Kim Barrett and Helen
Raybould (gastrointestinal system), and Drs. Bruce White and John Harrison (endocrine and reproductive
systems). We would like to thank the following individuals for their contributions to previous editions:
Drs. Kalman Rubinson and Eric Lang (nervous system), Dr. Achilles Pappano (cardiovascular system),
and Drs. Michelle Cloutier and Roger Thrall (respiratory system). We also welcome the following
authors: Dr. Mark Yeckel (nervous system), Dr. Robert Harvey (cardiovascular system), and Drs. Alix
Ashare and James Carroll (respiratory system). Importantly, Drs. Julianne Hall and Agnes SwiateckaUrban have joined us as authors and associate editors.
As in the previous editions of this textbook, we have attempted to emphasize broad concepts and to
minimize the compilation of isolated facts. Each chapter has been written to make the text as lucid,
accurate, and current as possible. We have included both clinical and molecular information in each
section, as feedback on these features has indicated that this information serves to provide clinical context
and new insights into physiologic phenomena at the cellular and molecular levels.
The human body consists of billions of cells that are organized into tissues (e.g., muscle, epithelia, and
nervous tissue) and organ systems (e.g., nervous, cardiovascular, respiratory, renal, gastrointestinal,
endocrine, and reproductive). For these tissues and organ systems to function properly, and thus allow
humans to live and carry out daily activities, several general conditions must be met.
First and foremost,
the cells within the body must survive. Survival requires adequate cellular energy supplies, maintenance
of an appropriate intracellular milieu, and defense against a hostile external environment. Once cell
survival is ensured, the cell can then perform its designated or specialized function (e.g., contraction by
skeletal muscle cells). Ultimately, the function of cells, tissues, and organs must be coordinated and
regulated. All of these functions are the essence of the discipline of physiology and are presented
throughout this book. What follows is a brief introduction to these general concepts.
Cells need a constant supply of energy. This energy is derived from the hydrolysis of adenosine
triphosphate (ATP). If not replenished, the cellular ATP supply would be depleted in most cells in less
than 1 minute. Thus, ATP must be continuously synthesized.
This in turn requires a steady supply of
cellular fuels. However, the cellular fuels (e.g., glucose, fatty acids, and ketoacids) are present in the
blood at levels that can support cellular metabolism only for a few minutes. The blood levels of these
cellular fuels are maintained through the ingestion of precursors (i.e., carbohydrates, proteins, and fats).
In addition, these fuels can be stored and then mobilized when ingestion of the precursors is not possible.
The storage forms of these fuels are triglycerides (stored in adipose tissue), glycogen (stored in the liver
and skeletal muscle), and protein. The maintenance of adequate levels of cellular fuels in the blood is a
complex process involving the following tissues, organs, and organ systems:
• Liver: Converts precursors into fuel storage forms (e.g., glucose → glycogen) when food is
ingested, and converts storage forms to cellular fuels during fasting (e.g., glycogen→ glucose
and amino acids → glucose).
• Skeletal muscle: Like the liver, stores fuel (glycogen and protein) and converts glycogen and
protein to fuels (e.g., glucose) or fuel intermediates (e.g., protein→ amino acids) during fasting.
•
Gastrointestinal tract: Digests and absorbs fuel precursors.
• Adipose tissue: Stores fuel during feeding (e.g., fatty acids → triglycerides) and releases the fuels
during fasting.
• Cardiovascular system: Delivers the fuels to the cells and to and from their storage sites.
• Endocrine system: Maintains the blood levels of the cellular fuels by controlling and regulating
their storage and their release from storage (e.g., insulin and glucagon).
• Nervous system: Monitors oxygen levels and nutrient content in the blood and, in response,
modulates the cardiovascular, pulmonary, and endocrine systems and induces feeding and
drinking behaviors.
In addition to energy metabolism, the cells of the body must maintain a relatively constant intracellular
environment to survive. This includes the uptake of fuels needed to produce ATP, the export from the cell
of cellular wastes, the maintenance of an appropriate intracellular ionic environment, the establishment of
a resting membrane potential, and the maintenance of a constant cellular volume. All of these functions are
carried out by specific membrane transport proteins.
The composition of the extracellular fluid (ECF) that bathes the cells must also be maintained
relatively constant. In addition, the volume and temperature of the ECF must be regulated. Epithelial cells
in the lungs, gastrointestinal tract, and kidneys are responsible for maintaining the volume and
composition of the ECF, while the skin plays a major role in temperature regulation. On a daily basis,
H2O and food are ingested, and essential components are absorbed across the epithelial cells of the
gastrointestinal tract. This daily intake of solutes and water must be matched by excretion from the body,
thus maintaining steady-state balance.
The kidneys are critically involved in the maintenance of steadystate balance for water and many components of the ECF (e.g., Na
+
, K+
, HCO3
−
, pH, Ca
++
, organic
solutes). The lungs ensure an adequate supply of O2
to “burn” the cellular fuels for the production of ATP
and excrete the major waste product of this process (i.e., CO2
). Because CO2 can affect the pH of the
ECF, the lungs work with the kidneys to maintain ECF pH.
Because humans inhabit many different environments and often move between environments, the body
must be able to rapidly adapt to the challenges imposed by changes in ambient temperature and
availability of food and water. Such adaptation requires coordination of the function of cells in different
tissues and organs as well as their regulation. The nervous and endocrine systems coordinate and regulate
cell, tissue, and organ function.
The regulation of function can occur rapidly (seconds to minutes), as is
the case for levels of cellular fuels in the blood, or over much longer periods of time (days to weeks), as
is the case for acclimatization when an individual moves from a cool to a hot environment or changes
from a high-salt to a low-salt diet.
The function of the human body represents complex processes at multiple levels. This book explains
what is currently known about these processes. Although the emphasis is on the normal function of the
human body, discussion of disease and abnormal function is also appropriate, as these often illustrate
physiologic processes and principles at the extremes.
The authors for each section have presented what they believe to be the most likely mechanisms
responsible for the phenomena under consideration. We have adopted this compromise to achieve brevity,
clarity, and simplicity.
