Chapter One: The Human Body
M.C. Shamier, MD
Shenzhou University
Subjects
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Anatomy
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Anatomy defined
The language of anatomy
Physiology
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Physiology defined
Levels of organization
Homeostasis
Anatomy
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Greek: ἀνατέμνειν “to cut open”
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tonsillec-tomy: cutting away the tonsils of the throat.
The study of the structure of living things
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Michiel van Mierevelt, 1617
Subdivisions
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Gross or macroscopic anatomy
Microscopic anatomy
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Histology
Cytology
Developmental anatomy and embryology
Radiographic anatomy
Pathological anatomy
Histology and cytology
Radiographic and pathological anatomy
The language of anatomy
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Anatomical position
Directional terms
Regional names
Body planes
Abdominopelvic
regions
Body cavities
Arbitrary
Physiologic
The language of anatomy
Anatomical position
Directional terms
Directional terms
Directional terms
Directional terms
Directional terms
Regional names
Body planes
Abdominopelvic regions
Body cavities
“Body cavities are spaces within the body that are closed to the
outside and contain the internal organs.”
Body cavities
Example: cranial and spinal cavity
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Together one continuous space, home to the central
nervous system (CNS)
Confined by bone: skull and vertebral column
Filled with cerebrospinal fluid
Are there any questions?
Next: Physiology
Physiology
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Greek:
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Φύσις: “nature
-λογία: “the study of”
The science of the functioning of living things.
Inseperately connected to anatomy:
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function reflects shape
Levels of structural organization
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Question:
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What is the smallest unit that the body is essentially composed
of?
Levels of structural organization
Question
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Could you think of a seventh level?
The seventh level: environmental context
Hendrick Avercamp
New York City
And the environment also contains:
Yellow fever
Organism and environment
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The organism is subject to:
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Climate
Microbes
Social interaction
Air pressure
And dependent on the environment for:
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Oxygen
Nutrients
Water
Boundaries
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Question:
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What seperates the organism from its environment?
‘Milieu intérieur’ and ‘milieu extérieur’
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“The fixity of the milieu supposes a perfection of the
organism such that the external variations are at each
instant compensated for and equilibrated. All of the vital
mechanisms, however varied they may be, have always
one goal, to maintain the uniformity of the conditions of life in
the internal environment.The stability of the internal
environment is the condition for the free and
independent life.”
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Claude Bernard, French Physiologist, 1854:
Example: Temperature
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Question
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What is the baseline temperature of the human body?
Question
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What happens when the environmental temperature drops?
Example: Temperature
This is called: Homeostasis
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Homeostasis:
 The ability of the body to maintain a relatively constant
internal environment, regardless of environmental changes.
How does it work?
The mechanism of negative feedback: failure leads to imbalance
which means disease.
Concluded
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There are several levels of structural organization within
an organism: from the atom to the organism (living in an
environment).
All vital systems work together to maintain a stable
internal environment, compensating for external
variations. The mechanism is negative feedback.
This is called homeostasis.
End of Chapter One