Gross AnatomyLecture LECTURE GROSS ANATOMY Objektif At the abdominal cavity by benbenzhou


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									                               LECTURE 1
                             GROSS ANATOMY

At the end of the lecture students will understand the anatomical terms used
to describe the animal body/organs and be able to differentiate their meaning.


During this lesson, you will learn anatomical terms appropriate for describing
areas of the body and directional terms commonly used in gross and
topographical anatomy to describe the relationship and location of parts of the

Anatomical terms for the human body may be different than those used for
animals. Why is there a difference in terminology?

Anatomy - concerned with form, disposition, and structure of organs that form
                   the body
Gross anatomy - structures that are visible to the naked eye
Microscopic anatomy (histology) -        invisible structures that form the
                                  gross anatomical characteristic of the
Developmental anatomy (embryology) - studies the growth of the unborn


Directional terms are used to describe the positions of structures on the body
relative to other structures or locations. Each directional term usually has a
partner term with an opposing meaning. Just as you tell a stranger how to get
to your home, medicine has terms that are useful in describing the location of
a laceration, a preferred injection site, an area to be prepared for a surgical
procedure, or a fracture on a radiograph.

Cranial means the structure is closer to the head of the animal.
Caudal indicates the structure being described is closer to the tail.
For structures on the head, rostral means the structure is closer to the nose,
and caudal means the structure is closer to the back of the head.
Medial means the structure is closer to the midline of the limb, trunk, or head.
Lateral indicates the structure is farther way from the midline.
Dorsal means the structure is closer to the top side (back) of the animal.
Ventral means the structure is closer to the bottom side (belly) of the animal.


Proximal describes structures that are nearer to the attachment of the
appendage to the body.

Gross Anatomy/Lecture 1                                                       1
Distal means the structure is farther away from the attachment to the body
(think DISTANT).
The relationship of the front and back sides of the legs can be described
dorsal to the carpus or tarsus by using cranial and caudal:
Cranial means the structure is closer to the front side of the leg.
Caudal indicates the structure is closer to the back side of the leg.
For structures distal to the carpus or tarsus, dorsal is used to describe the
cranial surface.
Palmar is used to describe the caudal surface of the forelimb
Plantar the similar area on the hindlimb.
Positions relative to the outer surface of the animal are described by the terms
superficial and deep.
Superficial means the structure is near the body surface.
Deep indicates the structure is farther away from the surface of the animal.


Transverse section - divides head and trunk into an anterior and posterior
                   - divides an appendage into proximal and distal portions
                   - perpendicular to long axis

Dorsal plane        - divides the head or trunk into dorsal and ventral portions

                    - parallel to the long axis

Sagittal plane      - divides body part into right and left sections
                    - parallel to the long axis

Median plane        - sagittal plane exactly on the midline of the body part



Head - referred to as the cranial or cephalic region
Neck - cervical region
Trunk - includes the thorax, abdomen, flank, lumbar, inguinal, and pelvic
Chest - the thorax, or thoracic region
Withers -    the high point at the junction of the neck and back
             formed by the top of the scapula and the thoracic vertebrae
Diaphragm - separates (dotted line) the thorax and abdomen and attaches to
             the costal arch. The dotted line represents the position of the
             diaphragm in the median plane.
Lumbar - corresponds to the lower back

Gross Anatomy/Lecture 1                                                        2
Flank -       a fold of skin attaching the stifle and thigh to the abdominal area
              lateral to abdominal region
Pelvic region (canal) - surrounded by the os coxae (bones forming the pelvis)
                      contains the reproductive organs and part of the urinary
                      tract communicates with the abdominal cavity
Inguinal region - ventral aspect of the pelvis; located between the hind legs
Perineal region
       perineum - area containing the anus or vulva
       surrounds the external openings of urinary, digestive, and reproductive
Rump - area dorsal to the pelvis and beginning of the tail

The dotted lines on the Weimaraner dog above and the Arabian horse below
represent the cranial extent of the diaphragm, or how far forward the
diaphragm domes into the thoracic cavity on the midline of the body. This line
also indicates that some of the organs of the abdominal cavity, such as the
liver and stomach, are partially or completely covered by the rib cage. Thus,
when asculting the thoracic cavity, normal gastrointestinal sound could be
easily heard when listening to the heart.



Shoulder -formed by the scapula and humerus
Brachium - the arm, found between the shoulder and elbow
Antebrachium - the forearm, found between the elbow and carpus
Carpus - equivalent to the human wrist and consists of several small bones
and joints
Metacarpus - connects the carpus with digit; also known as the cannon bone
in the horse.
Digits - toes, usually consist of 3 phalangeal bones each; the number of
metacarpal bones corresponds to the number of digits.
Forepaw - consists of carpal, metacarpal, and phalangeal bones


Pelvic girdle - consists of the os coxae or fusion of the ilium, pubis, and
Hip joint - articulation between the femur and the pelvis
Thigh - found between the hip joint and the stifle joint
Stifle joint - articulation between the femur, tibia, and fibula, and also contains
the patella (knee)
Leg - found between the stifle joint and the tarsus
Tarsus - equivalent to the human ankle; consists of several small bones and
Metatarsus - connects the tarsus with the digit, also known as the cannon
bone in the horse

Gross Anatomy/Lecture 1                                                          3
Digits - toes, consist of three phalangeal bones; the number of metatarsal
bones corresponds to the number of digits.
Hindpaw - consists of tarsus, metatarsus, and digits


The number of digits varies amongst the species:

SPECIES                                   DIGITS PER LEG

Bovine                                           4
Canine/Feline                                    4-5
Caprine/Ovine                                    4
Equine                                           1
Porcine                                          4

In both ruminants and pigs, 2 digits normally support the weight of the body.
In ruminants, the two non-weight supporting digits are vestigial and are called
In horses, one digit supports the weight of the body.
In dogs and cats, four digits support the weight of the body. The fifth digit, if
present, is called a dewclaw.


BODY CAVITIES are the compartments of the body the thoracic cavity
contains the heart and pericardium, lungs and pleura, and the mediastinum
and thymus the thoracic cavity is bounded laterally by the ribs (covered by
costal pleura) and the diaphragm caudally (covered by diaphragmatic pleura)
the thoracic and abdominal cavities are separated by the diaphragm the
abdominal cavity contains most of the gastrointestinal tract as well as the
kidneys and adrenal glands the abdominal cavity is bounded cranially by the
diaphragm, laterally by the body wall, and caudally by the pelvic cavity the
abdominal and pelvic cavities are continuous the pelvic cavity contains most
of the urogenital system as well as the rectum the pelvic cavity is bounded
cranially by the abdominal cavity, dorsally by the sacrum, and laterally by the

Gross Anatomy/Lecture 1                                                        4

Anatomical language must be precise and ambiguous. This differs from the
human anatomical position.


The planes of the body are formed by any two points that can be connected
by a straight line.

Median plane       divides the head, body, or limb longitudinally into equal
                   right and left halves.

Sagittal plane     passes through the head, body, or limb parallel to the
                   median plane.

Transverse plane   cut across the head, body, or limb at a right angle to its
                   long axis, or across the long axis of an organ or a part.

Dorsal plane       runs at right angles to the median and transverse planes
                   and divides the body or head into dorsal and ventral

Ventral            lie towards the belly or the corresponding surface of the
                   head and tail.

Cranial            lie towards the head.

Caudal             towards the tail.

Rostral            towards the muzzle.

Medial             lie towards the median plane.

Lateral            lie towards the side of the animal.

Proximal           structures that lie toward junction with the body.

Distal             structures that lie at a greater distance from the junction.

Palmar             (palm of the hand) in the fore limb.

Plantar            (sole of the foot) in the hind limb.


Gross Anatomy/Lecture 1                                                           5
Flexion            the movement of one bone on another so that the angle
                   between them is reduced.

Extension          the lengthening of a part by increasing the angle between
                   bones, straightening the limb, digit, or spine.

Abduction          the moving of a part away from the median plane.

Adduction          the moving of a part toward themedian plane.

Rotation           the movement of a part around its long axis (action of the
                   radius when using a screwdriver).

Supination         lateral rotation of the paw so that the palmer or plantar
                   surface faces medially or dorsally.

Pronation          medial rotation so that the palmar or plantar surface of
                   the paw faces ventrally.

Gross Anatomy/Lecture 1                                                    6

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