Download Learning Modules - Medical Gross Anatomy Anatomical

Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 1 of 9
In order to accurately describe the
human body, a basic set of anatomical
terms must be known.
To start, there are 3 types of
primary or cardinal planes that pass
through the body: sagittal, coronal,
and transverse.
The sagittal plane is named for
the sagittal suture, which is a mid-line
suture joint of the skull. It is also
known as the median or mid-sagittal
plane, and it divides the body into right
and left halves. Planes passing parallel
but not in the mid-line are called parasagittal planes.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 2 of 9
A coronal plane, also called a
frontal plane, is any plane passing
down through the body parallel to the
coronal suture of the skull, dividing
the body into front and back portions.
Coronal planes are therefore
perpendicular to sagittal planes and
pass through the length of the body.
Transverse planes are perpendicular to both
sagittal and coronal planes. They pass through the
width of the body in a horizontal or transverse
direction, similar to the slices of a loaf of bread.
Transverse planes divide the body into upper and
lower sections, and are also called horizontal or
axial planes or cross-sections.
Any plane passing through the body not parallel
to one of the three primary or cardinal planes is
called oblique.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 3 of 9
To establish the frame of reference for all of the parts of the body,
the body should be thought of as being positioned in an ideal pose
called the anatomical position. To assume the anatomical position,
stand erect, feet together, head facing forward, upper limbs at the side,
with the palms facing forward. By placing or imagining the body in this
position, all body parts can then be related to each other through the
use of relative terms that describe the location within the body.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 4 of 9
Superfical - Deep
A superficial structure is closer to the body
surface (skin) than a deeper structure.
Example: The sternum (breast-bone) is
superficial to the more deeply lying heart.
Superior - Inferior
Superior means toward the top of the head. Inferior means
toward the bottom of the feet. Cranial and caudal are often
used interchangeably with superior and inferior.
Example: The heart is superior to the liver.
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Anatomical Orientation - Page 5 of 9
Anterior - Posterior /
Ventral - Dorsal
Anterior or ventral is toward the
front of the body surface. Posterior
or dorsal is toward the back of the
body surface.
Example: The vertebral column is
dorsal to the more anteriorly placed
sternum.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 6 of 9
Median - Medial - Intermediate Lateral
Medial means toward the midline of
the body, whereas lateral structures
lie further away from the midline.
Intermediate structures lie between
medial and lateral structures, and
median structures lie on the midline
of the body.
Example: The trachea is a median
structure. It lies medial to the more
laterally placed point or top of the
shoulder. The clavicle is intermediate
between these two. One could also
say that the clavicle is medial to the
point of the shoulder, but lateral to
the trachea.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 7 of 9
Proximal - Distal
In referring to structures within the limbs specifically, the term
proximal means toward the limb's attachment to the trunk, while
distal means away from its attachment.
Example: The knee is proximal to the more distally placed ankle.
These terms can also be used to describe location along linear
structures within the trunk, such as the digestive tract or arteries.
Within these structures, the normal direction of flow determines
proximal or upstream from distal or downstream. However, in
veins and lymphatic vessels, blood or lymph flows distal to
proximal.
Example: The descending colon is distal to the transverse and
ascending colon.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 8 of 9
The relative terms for location are often
used in combinations, since most
structures are not related to each other
in only a single dimension.
Example: The nipple is superolateral to
the umbilicus or belly-button.
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Learning Modules - Medical Gross Anatomy
Anatomical Orientation - Page 9 of 9
In addition to these relative terms, certain body regions are
more rigorously defined anatomically. The upper limb,
commonly referred to as the "arm", is more precisely defined as
the arm extending from shoulder to elbow, the forearm from
elbow to wrist, and the hand distal to the wrist. Similarly, the
lower limb is made up of the thigh, from hip to knee, the leg
which extends from knee to ankle, and the foot distal to the
ankle.
Copyright© 2002 The University of Michigan. Unauthorized use prohibited.