Transcript History and branches of Anatomy

HISTORY AND BRANCHES OF ANATOMY
Anatome
Anatomy
(Greek anatome, “dissection”)
 a subfield of biology, the
study of the structure of living
things.
 3 main areas of anatomy:
cytology studies the
structure of cell; histology
examines the structure of
tissues; and gross anatomy
deals with organs and organ
groupings called systems.
 Comparative anatomy
strives to identify general
structural patterns in families
of plants and animals,
provided the basis for the
classification of species.
 Human anatomy is a crucial
element of the modern
medical curriculum.
 The proper understanding of
structure implies a
knowledge of function, hence
inseparable to Physiology.
The birth of biology: 5th - 4th century BC
 The first man to make a
significant contribution in
biology is Alcmaeon, living in
Crotona in the 5th century.
Alcmaeon is the first scientist
known to have practised
dissection in his researches.
 The subsequent Greek theory,
subscribed to even by Aristotle,
is that the heart is the seat of
intelligence.
 Alcmaeon reasons that since a
blow to the head can affect the
mind, in concussion, this must
be where reason lies.
 His aim is not anatomical, for his
interest lies in trying to trying to
find the whereabouts of human
intelligence.

In dissecting corpses to pursue
this idea, he observes passages
linking the brain with the eyes
(the optic nerves) and the back
of the mouth with the ears
(Eustachian tubes).
Human vivisection: c.300 BC
 Early in the 3rd century
BC two surgeons in
Alexandria, Herophilus
and Erasistratus,
make the first scientific
studies designed to
discover the workings
of human anatomy.
 Basis of science in the
modern times.
 (they acquire much of
their information from
vivisection of convicted
criminals).
The influential errors of Galen: 2nd century AD

Galen - The newly appointed chief
physician to the gladiators in
Pergamum, in AD 158

The appointment gives him the
opportunity to study wounds of all
kinds.

But it is Galen's dissection of apes
and pigs which give him the detailed
information for his medical tracts on
the organs of the body. Nearly 100
of these tracts survive.
 Galen is able to demonstrate
that living arteries contain
blood.

His error :the blood goes back
and forth from the heart in an
ebb-and-flow motion.
 Through his experiments Galen
is able to overturn many longheld beliefs that the arteries
contain air - carrying it to all
parts of the body from the heart
and the lungs (based originally
on the arteries of dead animals,
which appear to be empty).
Leonardo's anatomical drawings: AD 1489-1515
 Leonardo da Vinci made
a series of anatomical
drawings.
 Over the next twenty-
five years he dissects
about thirty human
corpses, many of them
at a mortuary in Rome.
 His drawings, amounting
to some 750, include
studies of bone
structures, muscles,
internal organs, the brain
and even the position of
the foetus in the womb.
 His studies of the heart
suggest that he was on
the verge of discovering
the concept of the
circulation of the blood.
Vesalius and the science of anatomy: AD
1533-1543
 Vesalius gives a public
demonstration of the
inaccuracies of Galen's
anatomical theories, which
are still the orthodoxy of
the medical profession.
 Vesalius is able to show
that in many cases
Galen's observations
are indeed correct for
the ape, but bear little
relation to the man.
 He ensured accurate distribution
of an image in printed form - the
art of the woodcut.

His studies inaugurate the
modern science of anatomy.
 in 1543 - De humani corporis
fabrica
(The Structure of the
Human Body).
Harvey and the circulation of
the blood: AD 1628
 William Harvey – Wrote
Exercitatio anatomica de motu
cordis et sanguinis in animalibus
('The Anatomical Function of the
Movement of the Heart and the
Blood in Animals').
 Blood, he shows, does not drift
in the body in any sort of
random ebb and flow.

Instead it is pumped endlessly
round a very precise circuit.

By a long series of
dissections (from dogs and
pigs down to slugs and
oysters), and by a process of
logical argument
 But there are two missing
ingredients. His theory
implies that there must be a
network of tiny blood
vessels bringing the blood
from the arterial system to
the venous system and
completing the circuit
Malpighi and the microscope:
AD 1661
 Malpighi is the first
scientist to observe the
capillaries, the tiny
blood vessels in which
blood circulates
through flesh.
 (frog's lung) In the
enlarged image of the
blood is all contained
within
 This strengthened the
missing link in Harvey's
circulation of the blood
has been found.
Leeuwenhoek and the
microscope: AD 1674-1683
 he uses a simple microscope
with a single lens - in effect a
tiny and extremely powerful
magnifying glass.
 he is the first scientist to give an
accurate description of red blood
corpuscles.
 he observes and depicts
spermatozoa in the semen of a
dog.
 he provides a drawing of
animalculae (or bacteria) seen in
saliva and dental plaque.
 the first to wander with such
enlarged vision among the
minutiae of the animal
kingdom.
 His account of the common
flea follows its development
from egg to the practical
perfection of its adult
anatomy. His researches
demonstrate for the first time
that the tiniest living things
have a life cycle and
generative systems like any
larger creature
Microscopic anatomy: 17th 20th century AD

 Félix Dujardin identifies a
viscous translucent substance
as being common to all forms
of life; it is later given the
name protoplasm.
 Robert Brown discovers in
plants the nucleus at the
centre of every cell.
Matthias Schleiden and Theodor Swann
give the first coherent account of cell
formation as the building process of all life
Anatomy - Anatomical Nomenclature
 What are these?
 4D/4E – just an add on
to your studies... It
might help in the
future...
 Research.
Anatomy - Anatomical Nomenclature
 standard anatomical
position - When the
human body is in the
standard anatomical
position it is upright,
erect on two legs,
facing frontward, with
the arms at the sides
each rotated so that
the palms of the hands
turn forward.

In the standard anatomical position,
superior means toward the head or
the cranial end of the body.

The term inferior means toward the
feet or the caudal end of the body.

The frontal surface of the body is
the anterior or ventral surface of the
body. Accordingly, the terms
"anteriorly" and "ventrally" specify a
position closer to—or toward—the
frontal surface of the body. The back
surface of the body is the posterior
or dorsal surface and the terms
"posteriorly" and "dorsally" specify a
position closer to—or toward—the
posterior surface of the body.


The terms superficial and deep relate
to the distance from the exterior
surface of the body. Cavities such as
the thoracic cavity have internal and
external regions that correspond to
deep and superficial relationships in
the midsagittal plane.
The bones of the skull are fused by
sutures that form important
anatomical landmarks. Sutures are
joints that run jaggedly along the
interface between the bones. At
birth, the sutures are soft, broad,
and cartilaginous. The sutures
eventually fuse and become rigid
and ossified near the end of puberty
or early in adulthood.

The sagittal suture unties the parietal bones of
the skull along the midline of the body. The
suture is used as an anatomical landmark in
anatomical nomenclature to establish what
are termed sagittal planes of the body. The
primary sagittal plane is the sagittal plane that
runs through the length of the sagittal suture.
Planes that are parallel to the sagittal plane,
but that are offset from the midsagittal plane
are termed parasagittal planes. Sagittal planes
run anteriorly and posteriorly, are always at
right angles to the coronal planes. The medial
plane or midsagittal plane divides the body
vertically into superficially symmetrical right
and left halves.

The medial plane also establishes a centerline
axis for the body. The terms medial and lateral
relate positions relative to the medial axis. If a
structure is medial to another structure, the
medial structure is closer to the medial or
center axis. If a structure is lateral to another
structure, the lateral structure is farther way
from the medial axis. For example, the lungs
are lateral to the heart.

The coronal suture unites the frontal bone with the parietal
bones. In anatomical nomenclature, the primary coronal
plane designates the plane that runs through the length of
the coronal suture. The primary coronal plane is also
termed the frontal plane because it divides the body into
frontal and back halves.

Planes that divide the body into superior and inferior
portions, and that are at right angles to both the sagittal
and coronal planes are termed transverse planes.
Anatomical planes that are not parallel to sagittal, coronal,
or transverse planes are termed oblique planes.

The body is also divided into several regional areas. The
most superior area is the cephalic region that includes the
head. The thoracic region is commonly known as the chest
region. Although the celiac region more specifically refers to
the center of the abdominal region, celiac is sometimes
used to designate a wider area of abdominal structures. At
the inferior end of the abdominal region lies the pelvic
region or pelvis. The posterior or dorsal side of the body has
its own special regions, named for the underlying
vertebrae. From superior to inferior along the midline of the
dorsal surface lie the cervical, thoracic, lumbar and sacral
regions. The buttocks is the most prominent feature of the
gluteal region.

The term upper limbs or upper extremities
refers to the arms. The term lower limbs
or lower extremities refers to the legs.

The proximal end of an extremity is at
the junction of the extremity (i.e., arm or
leg) with the trunk of the body. The distal
end of an extremity is the point on the
extremity farthest away from the trunk
(e.g., fingers and toes). Accordingly, if a
structure is proximate to another
structure it is closer to the trunk (e.g.,
the elbow is proximate to the wrist). If a
structure is distal to another, it is farther
from the trunk (e.g., the fingers are distal
to the wrist).

Structures may also be described as
being medial or lateral to the midline
axis of each extremity. Within the upper
limbs, the terms radial and ulnar may be
used synonymous with lateral and
medial. In the lower extremities, the
terms fibular and tibial may be used as
synonyms for lateral and medial.


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
Rotations of the extremities may de
described as medial rotations (toward the
midline) or lateral rotations (away from the
midline).
Many structural relationships are described
by combined anatomical terms (e.g. the
eyes are anterio-medial to the ears).
There are also terms of movement that are
standardized by anatomical nomenclature.
Starting from the anatomical position,
abduction indicates the movement of an
arm or leg away from the midline or
midsagittal plane. Adduction indicates
movement of an extremity toward the
midline.
The opening of the hands into the
anatomical position is supination of the
hands. Rotation so the dorsal side of the
hands face forward is termed pronation.

The term flexion means movement toward the flexor
or anterior surface. In contrast, extension may be
generally regarded as movement toward the extensor
or posterior surface. Flexion occurs when the arm
brings the hand from the anatomical position toward
the shoulder (a curl) or when the arm is raised over the
head from the anatomical position. Extension returns
the upper arm and or lower to the anatomical position.
Because of the embryological rotation of the lower
limbs that rotates the primitive dorsal side to the adult
form ventral side, flexion occurs as the thigh is raised
anteriorly and superiorly toward the anterior portion of
the pelvis. Extension occurs when the thigh is returned
to anatomical position. Specifically, due to the
embryological rotation, flexion of the lower leg occurs
as the foot is raised toward the back of the thigh and
extension of the lower leg occurs with the kicking
motion that returns the lower leg to anatomical
position.

The term palmar surface (palm side) is applied to the
flexion side of the hand. The term plantar surface is
applied to the bottom sole of the foot. From the
anatomical position, extension occurs when the toes
are curled back and the foot arches upward and flexion
occurs as the foot is returned to anatomical position.

Rolling motions of the foot are described as inversion
(rolling with the big toe initially lifting upward) and
eversion (rolling with the big toe initially moving
downward).
Human anatomy in a nutshell

Human anatomy divides the body into the following distinct functional
systems: cutaneous, muscular, skeletal, circulatory, nervous, digestive,
urinary, endocrine, respiratory, and reproductive. This division helps the
student understand the organs, their relationships, and the relations of
individual organs to the body as a whole.

The cutaneous system consists of the integument—the covering of the
body, including the skin, hair, and nails. The skin is the largest organ in
the body, and its most important function is to act as a barrier between
the body and the outside world. The skin's minute openings (pores) also
provide an outlet for sweat, which regulates the body temperature.
Melanin, a dark pigment found in the skin, provides protection from
sunburn. The skin also contains oil-producing cells.


The muscles of the muscular system enable the body to move and
provide power to the hands and fingers. There are two basic types of
muscles. Voluntary (skeletal) muscles enable movements under
conscious direction (e.g., to walk, move an arm, or smile). Involuntary
(smooth) muscles are not consciously controlled, and operate
independent of conscious direction. For example, they play an important
role in digestion. The third type of muscle, cardiac muscle is involuntary,
but also is striated, as in skeletal muscles. Because cardiac muscle is selfcontractile it allows the heart to pumps blood throughout the body,
without pause, from early in embryogenesis to death.
The skeletal system, or the skeleton, is the general supportive structure
of the body. In addition, the skeletal system is the site of many important
and complex physiological and immunological processes. The skeletal
frame provides the support that muscles need in order to function. Of the
206 bones in the human body, the largest is the femur, or thigh bone.
The smallest are the tiny ear ossicles, three in each ear, named the
hammer (malleus), anvil (incus), and stirrup (stapes). Often included in
the skeletal system are the ligaments, which connect bone to bone; the
joints, which allow the connected bones to move; and the tendons, which
connect muscle to bone.

The circulatory system comprises the heart, arteries, veins, capillaries, blood and bloodforming organs, and the lymphatic sub-system. The four chambers of the heart allow the
heart to act as a dual pump to propel blood to the lungs for oxygenation (pulmonary system)
and to pump blood throughout the body (systemic circulation). From the heart, the blood
circulates through arteries. The blood is distributed through smaller and smaller tubes until it
passes into the microscopic capillaries which bathe every cell. The veins collect the "used"
blood from the capillaries and return it to the heart.

The nervous system consists of the brain, the spinal cord, and the sensory organs that
provide information to them. For example, our eyes, ears, nose, tongue, and skin receive
stimuli and send signals that travel both electrically and chemically to the brain. The brain is
an intricate system of complicated neurons (nerve cells) that allow us to process sensory
information, visceral signals (e.g. regulating breathing, body temperature, etc.), and perform
cognitive thought.

The digestive system is essentially a long tube extending from the mouth to the anus. Food
entering the mouth is conducted through the stomach, small intestine, and large intestine,
where accessory organs contribute digestive juices to break down the food, extracting the
molecules that can be used to nourish the body. The unusable parts of the ingested food are
expelled through the anus as fecal matter. The salivary glands (in the mouth), the liver, and
the pancreas are the primary digestive glands.

The urinary system consists of the kidneys, the bladder, and the connecting tubules. The
kidneys filter water and waste products from the blood and pass them into the bladder. At
intervals, the bladder is emptied through the urinary tract, ridding the body of unneeded
waste.

The endocrine system consists of ductless (endocrine) glands that produce hormones that
regulate various bodily functions. The pancreas secretes insulin to regulate sugar
metabolism, for example. The pituitary gland in the brain is the principal or "master" gland
that regulates many other glands and endocrine functions.

The respiratory system includes the lungs, the diaphragm, and the tubes that connect them
to the outside atmosphere. Respiration is the process whereby an organism absorbs oxygen
from the air and returns carbon dioxide. The diaphragm is the muscle that enables the lungs
to work.

Finally, the reproductive system enables sperm and egg to unite and the egg to remain in the
uterus or womb to develop into a functional human.