When
anatomists or doctors discuss the human body, they refer to specific areas in
accordance with a universally accepted standard position called the Anatomical
position.
It is essential to understand this position, because much of the body
terminology employed in this course refers to this body positioning,
regardless of the position the body happens to be in.
The anatomical position in humans is standing erect, facing forward,
arms at sides and palms forward. Quadrupedal
(four footed) organisms have a slightly different position, which is standing
erect, facing forward, and all four feet on the ground.
This difference in positions results in different connotations for a
four-legged animal compared to a human.
Study
the terms below, referring to figure one and to the figure on page 4 of your
lab book. The following terms are
dependent on an assumption of anatomical position.
Superior/inferior
(above/below): these terms refer to placement of a body structure along the long axis
of the body. Superior structures
always appear above other structures. For
example, the nose is superior to the mouth, and the abdomen is inferior to the
chest region.
Anterior/posterior
(front/back): In humans the most anterior structures are those that are most forward,
the face, chest and abdomen. Posterior
structures or surfaces are those toward the backside of the body. For
instance, the spine is posterior to the heart
Medial/lateral
(towards the midline/away from the midline): The ear is lateral to the
bridge of the nose; the sternum (breastbone) is medial to the ribs.
The next four terms are more absolute.
That is their applicability is not relative to a particular body
position, and they consistently have the same meaning in all vertebrate
animals.
Cephalad/caudal
(towards the head/away from the head): In humans these terms are used interchangeably with
superior and inferior. But in four-legged animals they are synonymous with
anterior and posterior respectively.
Dorsal/ventral
(backside/belly side): these terms are used chiefly in discussing the comparative
anatomy of animals, assuming the animal is standing. Dorsum is Latin
meaning "back", thus dorsal refers to the backside of the animal's
body or of any other structure. For
instance, the posterior surface of the leg is its dorsal surface. The term ventral
derives from the Latin term venter,
meaning "belly", and thus refers to the belly side of animals. In
humans the term ventral and dorsal
may be used interchangeably with the terms anterior
and posterior, but in four-legged
animals ventral and dorsal are synonymous with inferior and superior
respectively.
Proximal/distal
(nearer the trunk or attached end/farther from the trunk or point of
attachment):
These terms are used primarily to locate various areas of the body limbs. For
example, the fingers are distal to the elbow; the knee is proximal to the
toes.
Superficial/deep
(towards or at the body surface/away from the body surface or more internal):
these terms locate body organs according to their relative closeness to the
body surface. For example, the
lungs are deep to the rib cage, and the skin is superficial to the skeletal
muscles.
Central/peripheral
(principle part/extensions from the principle part or to the side of principle
part):
Parietal/visceral (wall of a cavitylorgans -within a cavity): These terms refers to organs within a body cavity.
Before continuing, use a human torso model, a skeleton or your own body to specify the relationship between the following structures. Use the correct anatomical terminology.
The wrist is _________________________ to the hand, but ______________________ to the shoulder.
The trachea (windpipe) is _______________ to the spine
The brain is _________________________ to the spinal cord
The kidneys are ______________________ to the liver
The tip of the nose is __________________ to the cheekbones.
SURFACE ANATOMY. Refer to figure two for the following terms
Oral:
pertaining to the mouth
Orbital:
pertaining to the bony eye sockets
Buccal:
pertaining
to the cheek
Cervical:
pertaining to the neck region
Thoracic:
pertaining to the chest
Axillary:
pertaining to the armpit.
Umbilical:
pertaining to the naval
Pubic:
pertaining to the genital region
Brachial:
pertaining to the arm (region of upper limb between shoulder and elbow).
Inguinal:
pertaining to the area where the thigh meets the body trunk
Abdominal:
pertaining to the anterior body trunk region inferior to the ribs
Petellar:
pertaining to the anterior knee (kneecap) region
Occipital:
pertaining to the posterior surface of the head or base of the skull
Deltoid:
pertaining to the curve of the shoulder formed by the large deltoid muscle
Scapular:
pertaining to the scapula or shoulder blade area
Femoral:
pertaining to the thigh
Digital:
pertaining to the fingers or toes.
Lumbar:
pertaining to the area of the back between the ribs and hips
Gluteal:
pertaining to the buttocks or rump
Popliteal:
pertaining to the posterior knee region
Sural:
pertaining to the posterior surface of the leg
Calcanceal:
pertaining to the heel of the foot
The
body is three-dimensional and, in order to observe its internal structures, it
is often helpful and necessary to make use of a section,
or cut. When the section is made
through the body wall or through an organ, it is made along an imaginary
surface or line called a plane.
Anatomists
commonly refer to three planes (Figure Three) or sections, which lie at right
angles to one another.
Sagittal
plane:
A plane that runs longitudinally, dividing the body into right and left parts,
is referred to as a sagittal plane. If
it divides the body into equal parts, right down the median plane of the body,
it is called a midsagittal,
or median, plane.
All other planes are referred to as parasagittal planes.
Frontal
plane:
Sometimes called a coronal plane, the frontal plane is a longitudinal plane
that divides the body (or an organ) into anterior and posterior parts.
Transverse plane: A transverse plane runs horizontally, dividing the body into superior and inferior parts. When organs are sectioned along the transverse plane, the sections are commonly called cross sections