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INTRODUCTION HUMAN ANATOMY
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Anatomy: the word anatomy is derived from a Greek
word“Anatome” meaning to cut up. It is the study of
structures that make up the body and how those structures
relate with each other.
The study of anatomy includes many sub specialties. These
are Gross anatomy, Microscopic anatomy, Developmental
anatomy and Embryology.
Gross anatomy studies body structure without microscope.
Systemic anatomy studies functional relationships of organs
within a system whereas Regional anatomy studies body
part regionally. Both systemic and regional approaches may
be used to study gross anatomy
Microscopic anatomy (Histology) requires the use of
microscope to study tissues that form the various organs of
the body.
Homeostasis
When structure and function are coordinated the body
achieves a relative stability of its internal environment called
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homeostasis / staying the same. Although the external
environmental changes constantly, the internal environment
of a healthy body remains the same with in normal limits.
Under normal conditions, homeostasis is maintained by
adaptive mechanisms ranging from control center in the
brain to chemical substances called hormones that are
secreted by various organs directly into the blood streams.
Some of the functions controlled by homeostasis
mechanisms are blood pressure, body temperature,
breathing and heart rate.
Level of structural organization of the body
The human body has different structural levels of
organization, starting with atoms molecules and compounds
and increasing in size and complexity to cells, tissues, organs
and the systems that make up the complete organism.
Atoms molecules and compounds: - At its simplest level,
the body is composed of atoms. The most common elements
in living organism are carbon, hydrogen, oxygen, nitrogen
phosphorus and sulfur.
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Atoms → Molecule → Compounds.
Cell: The smallest independent units of life. All life depends
on the many chemical activities of cells. Some of the basic
functions of cell are: growth, metabolism, irritability and
reproduction.
Tissue: tissue is made up of many similar cells that perform
a specific function. The various tissues of the body are
divided in to four groups. These are epithelial, connective,
nervous and muscle tissue.
Epithelial tissue: - Found in the outer layer of skin, lining of
organs, blood and lymph vessels and body cavities.
Connective tissue: - Connects and supports most part of the
body. They constitute most part of skin, bone and tendons.
Muscle tissue: - Produces movement through its ability to
contract. This constitutes skeletal, smooth and cardiac
muscles.
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INTRODUCTION HUMAN ANATOMY
1
,2|Page
Anatomy: the word anatomy is derived from a Greek
word“Anatome” meaning to cut up. It is the study of
structures that make up the body and how those structures
relate with each other.
The study of anatomy includes many sub specialties. These
are Gross anatomy, Microscopic anatomy, Developmental
anatomy and Embryology.
Gross anatomy studies body structure without microscope.
Systemic anatomy studies functional relationships of organs
within a system whereas Regional anatomy studies body
part regionally. Both systemic and regional approaches may
be used to study gross anatomy
Microscopic anatomy (Histology) requires the use of
microscope to study tissues that form the various organs of
the body.
Homeostasis
When structure and function are coordinated the body
achieves a relative stability of its internal environment called
2
,3|Page
homeostasis / staying the same. Although the external
environmental changes constantly, the internal environment
of a healthy body remains the same with in normal limits.
Under normal conditions, homeostasis is maintained by
adaptive mechanisms ranging from control center in the
brain to chemical substances called hormones that are
secreted by various organs directly into the blood streams.
Some of the functions controlled by homeostasis
mechanisms are blood pressure, body temperature,
breathing and heart rate.
Level of structural organization of the body
The human body has different structural levels of
organization, starting with atoms molecules and compounds
and increasing in size and complexity to cells, tissues, organs
and the systems that make up the complete organism.
Atoms molecules and compounds: - At its simplest level,
the body is composed of atoms. The most common elements
in living organism are carbon, hydrogen, oxygen, nitrogen
phosphorus and sulfur.
3
, 4|Page
Atoms → Molecule → Compounds.
Cell: The smallest independent units of life. All life depends
on the many chemical activities of cells. Some of the basic
functions of cell are: growth, metabolism, irritability and
reproduction.
Tissue: tissue is made up of many similar cells that perform
a specific function. The various tissues of the body are
divided in to four groups. These are epithelial, connective,
nervous and muscle tissue.
Epithelial tissue: - Found in the outer layer of skin, lining of
organs, blood and lymph vessels and body cavities.
Connective tissue: - Connects and supports most part of the
body. They constitute most part of skin, bone and tendons.
Muscle tissue: - Produces movement through its ability to
contract. This constitutes skeletal, smooth and cardiac
muscles.
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