The history of anatomy as a science extends from the earliest
examinations of sacrificial victims to the sophisticated analyses of
the body performed by modern scientists. It has been marked, over time,
by a continually developing understanding of the functions of organs
and structures in the body. Methods have also advanced drastically,
advancing from examination of animals through dissection of cadavers to technologically complex techniques developed in the last century.
begins at least as early as 1600 BC, the date of publication of an Egyptiananatomicalpapyrus that has survied to this day; this treatise identifies a number of organs and shows a basic knowledge of blood vessels.
The earliest medical scientist of whose works any great part survives today is Hippocrates, a Greek
physician active in the late 5th and early 4th centuries BC (460-377
BC). His work demonstrates a basic understanding of musculoskeletal
structure, and the beginnings of understanding of certain organs, such
as the kidneys. Much of his work, however, and much of that of his
students and followers later, relies on speculation rather than
empirical observation of the body.
In the 4th century BC, Aristotle
and several contemporaries produced a more empirically founded system,
based on dissection of animals; works produced around this time are the
first to identify the difference between arteries and veins, and the relations between organs are described more accurately than in previous works.
The first use of human cadavers for anatomical research occurred later in the 4th century BC, when Herophilos and Erasistratus performed dissections of cadavers in Alexandria under the auspices of the Ptolemaic dynasty.
Herophilos in particular developed a body of anatomical knowledge much
more informed by the actual structure of the human body than previous
works had been.
The final major anatomist of ancient times was Galen,
active in the 2nd century AD. He compiled much of the knowledge
obtained by previous writers, and furthered the inquiry into the
function of organs by performing vivisection on animals. His collection of drawings, based mostly on dog anatomy, would hold as a "Gray's Anatomy of the ancient world" for 1500 years. The original text is long gone, and his work was only known to the Rennaissance
doctors through the careful custody of Arabic medicine, since the
Church destroyed it as heresy. Hampered by the same religious
restrictions as anatomists for centuries after him, Galen assumed that
anatomical structures in dogs were the same as for humans.
Anatomical research in the past hundred years has taken advantage of
technological developments and growing understanding of sciences such
as evolutionary and molecular biology to create a thorough understanding of the body's organs and structures. While disciplines such as endocrinology have explained the purpose of glands that previous anatomists could not explain, medical devices such as MRI machines and CAT scanners
have enabled researchers to study the organs of living people. Progress
today in anatomy is centered in the field of molecular biology, as the
macroscopic aspects of the field have now been catalogued and addressed.
History of anatomy
From Wikipedia, the free encyclopedia
Anatomy first found wide acceptance as a
science in ancient Greece.
(a) Hippocrates is regarded as the father of medicine because of the sound principles of medical practice he
(b) The Greek philosophy of body humors dominated medical thought for over 2,000 years.
(c) Aristotle pursued a limited type of scientific method in obtaining data; his writings contain some basic anatomy.
6. Alexandria was a center of scientific learning from 300 to 30 B.C.
(a) Human dissections and vivisections were performed in Alexandria.
(b) Erasistratus is referred to as the father of physiology because of his interpretations of various body functions.
7. Theoretical data was deemphasized during the Roman era.
(a) Celsus’s eight-volume work was a compilation of medical data from the
(b) Galen was an influential medical writer who made some important advances in anatomy; at the same time he introduced serious errors into the literature that went unchallenged for centuries.
(c) Science was suppressed for nearly
1,000 years during the Middle Ages, and dissections of human cadavers were prohibited.
(d) Anatomical writings were taken from Alexandria by Arab armies, and thus saved from destruction during the Dark Ages in Europe.
8. During the Renaissance, many great European universities were established.
(a) Andreas Vesalius and Leonardo da Vinci were renowned Renaissance men who produced monumental studies of the human form.
(b) De Humani Corporis Fabrica, written by Vesalius, had a tremendous impact on the advancement of human anatomy. Vesalius is regarded as the father of human anatomy.
9. Two major scientific contributions of the seventeenth and eighteenth centuries were the explanation of blood flow and the development of the microscope.
(a) In 1628, William Harvey correctly described the circulation of blood.
(b) Shortly after the microscope had been perfected by Antoni van Leeuwenhoek, many investigators added new discoveries to the rapidly changing specialty of microscopic anatomy.
10. The cell theory was formulated during the nineteenth century by Matthias Schleiden and Theodor Schwann, and cellular biology became established as a science separate from anatomy.
11. A trend toward simplification and standardization of anatomical nomenclature began in the twentieth century. In addition, many specialties within anatomy developed, including cytology, histology, embryology, electron microscopy, and radiology.
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Muscle (from Latin
musculus "little mouse" ) is contractile tissue of the body and is derived from the
mesodermal layer of embryonic
germ cells. Its function is to produce force and cause motion, either locomotion or movement
organs. Much of muscle contraction occurs without conscious thought and is necessary for survival, like
the contraction of the heart, or peristalsis (which pushes food
through the digestive
system). Voluntary muscle contraction is used to move the body, and can be
finely controlled, like movements of the finger or gross movements like the quadriceps muscle
of the thigh. There are 2 types of muscle
movement, slow twitch and fast twitch. Slow twitch movements act for a long time
but not very fast, whilst fast twitch movements act quickly, but not for a very
Agonist A muscle that causes motion.
AntagonistA muscle that can move the joint opposite to the movement produced by the agonist.
Target The primary muscle intended for exercise.
Synergist A muscle that assists another muscle to accomplish a movement.
StabilizerA muscle that contracts with no significant movement
Origin (b): muscle attatchment that moves least, generally more proximal.
Insertion (a): muscle attatchment that moves most, generally more distal.
Abduction: Lateral movement away from the midline of the body
Adduction: Medial movement toward the midline of the body
Circumduction: circular movement (combining flexion, extension, adduction, and abduction) with no shaft rotation
Extension: Straightening the joint resulting in an increase of angle
Eversion: Moving sole of foot away from medial plane
Flexion: Bending the joint resulting in a decrease of angle
Hyperextension: extending the joint beyond anatomical position
Inversion: Moving sole of foot toward medial plane
Pronation: Internal rotation resulting in appendage facing downward
Protrusion: Moving anteriorly (eg: chin out)
Supination: External rotation resulting in appendage facing upward
Retrusion: Moving posteriorly (eg: chin in)
Rotation: Rotary movement around the longitudinal axis of the bone
The cell is the structural and functional unit of all living organisms, and is sometimes called the "building block of life."Some organisms, such as bacteria, are unicellular, consisting of a single cell. Other organisms, such as humans, are multicellular. (Humans have an estimated 100 trillion or 1014 cells; a typical cell size is 10 µm; a typical cell mass is 1 nanogram.) The largest known cell is an ostrich egg.
The cell theory, first developed in 1839 by Schleiden and Schwann, states that all organisms
are composed of one or more cells. All cells come from preexisting
cells. Vital functions of an organism occur within cells, and all cells
contain the hereditary information necessary for regulating cell functions and for transmitting information to the next generation of cells.
The word cell comes from the Latin cellula, a small room. The name was chosen by Robert Hooke when he compared the cork cells he saw to the small rooms monks lived in.
Skeletal muscle is made up of thousands of cylindrical muscle fibers
often running all the way from origin to insertion. The fibers are bound
together by connective tissue through which run blood vessels and nerves.
Each muscle fibers contains:
an array of myofibrils that are stacked lengthwise and run the entire
length of the fiber.
an extensive smooth endoplasmic reticulum
The multiple nuclei arise from the fact that
each muscle fiber develops from the fusion of many cells (called
The number of fibers is probably fixed early in life. This is regulated by
myostatin, a cytokine that is
synthesized in muscle cells (and circulates as a hormone later in life).
Myostatin suppresses skeletal muscle development. Cattle and mice with
inactivating mutations in their myostatin genes develop much larger muscles.
Some athletes and other remarkably strong people have been found to carry one
mutant myostatin gene. These discoveries have already led to the growth of an
illicit market in drugs supposedly able to suppress myostatin.
In adults, increased strength and muscle mass comes about through an increase
in the thickness of the individual fibers and increase in the amount of
connective tissue. In the mouse, at least, fibers increase in size by attracting
more myoblasts to fuse with them. The fibers attract more myoblasts by releasing
the cytokine interleukin 4 (IL-4). Anything that lowers the level of
myostatin also leads to an increase in fiber size.
Because a muscle fiber is
not a single cell, its parts are often given special names such as
sarcolemma for plasma membrane
sarcoplasmic reticulum for endoplasmic reticulum
sarcosome for mitochondrion
sarcoplasm for cytoplasm
although this tends to obscure the
essential similarity in structure and function of these structures and those
found in other cells
The secretory cells can release their secretory products by one of three mechanisms.
the process of exocytosis. Vesicles open onto the surface of the cell,
and the secretory product is discharged from the cell without any further
loss of cell substance.
designates a mechanism
in which part of the apical cytoplasm of the cells is lost together
with the secretory product. The continuity of the plasma membrane is
restored by the fusion of the broken edges of the membrane, and the
cell is able to accumulate the secretory product anew. This mechanism
is used by apocrine sweat glands, the mammary glands and the prostate.
secretion designates the
breakdown and discharge of the entire secretory cell. It is only seen
in the sebaceous glands of the skin.
, branch of biology concerned with the study of body structure of
various organisms, including humans.
Comparative anatomy is concerned
with the structural differences of plant and animal forms.
Gunther von Hagens, the German anatomist who created "Body Worlds,"
poses with one of his displays. The exhibit puts real human specimens
on show, such as this one in Dallas. (Media Credit: Associated Press)Christopher Placek
The study of
similarities and differences in anatomical structures forms the basis
for classification of both plants and animals. Embryology (see embryo)
deals with developing plants or animals until hatching or birth (or
germination, in plants); cell biology covers the internal anatomy of
the cell, while histology
is concerned with the study of aggregates of similarly specialized
cells, called tissues. Related to anatomy is morphology, which involves
comparative study of the corresponding organs in humans and animals.
There are four major types of tissue present in the human body:
epithelial tissue (see epithelium), muscular tissue (see muscle), connective tissue, and nervous tissue (see nervous system).
Human anatomy is often studied by considering the individual systems
that are composed of groups of tissues and organs; such systems include
the skeletal system (see skeleton), muscular system, cutaneous system (see skin), circulatory system (including the lymphatic system), respiratory system (see respiration), digestive system, reproductive system, urinary system, and endocrine system.
Little was known about human anatomy in ancient times because
dissection, even of corpses, was widely forbidden. In the 2d cent., Galen,
largely on the basis of animal dissection, made valuable contributions
to the field. His work remained authoritative until the 14th and 15th
cent., when a limited number of cadavers were made available to the
medical schools. A better understanding of the science was soon
reflected in the discoveries of Vesalius, William Harvey, and John Hunter. Various modern technologies have significantly refined the study of anatomy: X rays, CAT scans, and magnetic resonance
imaging (MRI) are only several of the tools used today to obtain clear,
accurate representations of the inner human anatomy. In 1994, for the
first time, a detailed three-dimensional map of an entire human being
(an executed prisoner who volunteered his body) was made available
worldwide via the Internet using data from thousands of photographs,
CAT scans, and MRIs of tiny cross sections of the body.[H. Gray, Gray's Anatomy (1987).]
Longitudinal (interhemispheric) fissure
Between the cerebral
hemispheres. Its floor is the corpus callosum.
Lateral sulcus (sylvian fissure)
Separates temporal lobe
from frontal and parietal lobes
Landmark for underlying
Landmark for primary
motor and somatic sensory areas
Primary motor area
expressive speech area
Control of movement
Initiation of movements
Saccadic eye movements
(not pursuit or vergence)
association area; lesions cause apraxia, neglect
Higher order association
areas for language, calculation; lesions cause receptive aphasia
Higher order association
area for vision; eye-field for pursuit movements
(and the adjacent gyri)
Primary visual area
the occipital lobe
Visual association cortex
Highest order visual
association area, including memories of complex scenes
& middle part
Primary auditory area
and posterior parts
area; also called Wernicke's area; part of the association area for
Primary olfactory cortex
Includes primary and
association cortex for
olfaction. Afferents from all sensory association areas. Efferents to
to collateral sulcus)
association cortex for remembering people's faces