Vet Tech Terminology: The Musculoskeletal System

Bones

-hard form of connective tissue that makes up most of the skeleton

-composed of collagen and minerals such as calcium and phosphorus

-earliest stage of development: skeleton made up of cartilaginous tissue which softer and more flexible

-after birth, that fibrous tissue is converted into osseous tissue

Formation Of Bone

Osseous Tissue

-another name for bone tissue

Ossification

-process of bone formation

Osteoblast

-bone cell that forms bone tissues; aka immature bone cell

Osteoclast

-bone cell that absorbs and removes bone tissue; aka phagocyte of bone

Osteocyte

-bone

Bone Anatomy

Articular Cartilage

-thin layer of cartilage covering the bone in the joint space

Calcium

-most abundant mineral in the body; combined w/ phosphorus is forms calcium phosphate, which is the principle calcium salt and hard material found in bones and teeth

Cancellous Bones

-spongey or porous bone found at the end of long bones and in the inner portions of long bones

Collagen

-structural protein making up the white fibrous strands found in bone

Compact Bone

-hard, dense, bone tissue that forms the outer layer of the bone

-aka cortical bone

Diaphysis

-the shaft of a long bone

Endosteum

-the inner lining of bone; forms the lining of the medullary cavity

Epiphysis Plate

-cartilaginous region of long bones where length wise growth takes place; aka the physis of growth plate

Epiphysis

-each end of a long bone

-composed of cancellous bone and covered with w/ articular cartilage

Medullar Cavity

-central, hollowed-out portion in the shaft of a long bone that contains yellow bone marrow

Metaphysis

-flared portion of a long bone, between the diaphysis and the epiphyseal plate

Peritosteum

-membrane surrounding bone

-contain blood vessels and nerves

Red Bone Marrow

found in cancellous bone; site of hematopoiesis

Yellow Bone Marrow

-found in the diaphysis of bone and consists of fatty tissue

Long Bones

-bones longer than they are wide

-found in the front and rear limbs

-ex: femur, tibia, radius, and metacarpals

Short Bones

-bones are cuboidal(cube shaped)

-ex: carpals and tarpals

Flat Bones

-bones are actually two sheets of compact bone that allow for protection

-flat and thin

-ex: scapula, ribs, and bones of pelvis and skull

Sesamoid Bones

-small bones embedded in tendons

-get their names b/c of their sesame seed shape

ex: the patella

Irregular Bones

-bones that don't fit into the previous categories

-best classification is vertebrae

Related Terms and Processes

Acetabulum

Cup-like depression in the pelvis that creates the hip joint

Bone Head

-rounded articular process separated from the shaft of the bone by a neck

-covered in articular cartilage

ex: femoral calves and humeral head

Condyle

-knuckle-like projections at the distal end of some long bones

-covered by articular cartilage and articulate w/ other bones

-ex: femoral and humeral calves

Crest

-high projection or border projection of a bone

ex: is the crest of ilium; aka wing of ilium

Foramen

-a hole in bone that allows for the passage of nerves and vessels

ex: obturator foramen and foramen magnum

Fossa

-shallow cavity or depression in bone

ex: trochanteric fossa which lies between the greater and lesser trochanter

Groove

-a narrow, linear depression; aka sulcus

ex: bicipital groove on the humerus

Olecranon

-bony process at the proximal end of the ulna

Sinus

-a hallow space or cavity bone

-ex: nasal sinuses

Trochanter

-large, blunt, roughened process on the femur for attachment of muscles and tendons

Tubercle

-rounded process on many bones for the attachment of muscles and tendons

-ex: humeral tubercle

Tuberosity

-small roughened process on many bones for the attachment of muscles and tendons

ex: tibial tuberosity and ischiatic tuberosity

Divisions of the Skeleton

The Axial Skeleton

-consists of bones along the axis(center) of the body

The Appendicular Skeleton

-consists of the bones of the appendages(extremities)

The Visceral(Splanchnic) Skeleton

-consists of bones that are embedded in tissue

The Axial Skeleton

-included the skull, vertebrae(backbones), ribs, and sternum

-bones only on axis(midline)

The Skull

-composed of bones that protect the brain

Ethmoid Bone

-bone that forms the roof of the nasal cavity and the floor of the rostral cranial cavity(orbit of the eyes)

Frontal Bone

-paired bones making up the upper part of the face; the cranial aspect of the skull

Occiputal Bone

-the caudal aspect of the skull

Parietal Bone

-paired bones forming the sides and roof of the cranium

Sphenoid Bone

-wedge-shaped bone at the base of the skull

Temporal Bone

-paired bones forming the lower sides of the skull

Facial Bones

-make up front of the skull

-have spaces of air called sinuses

Hyoid Bones

-horseshoe-shaped bone at the base of the tongue and below the thyroid cartilage

Incisive Bone

-bone bearing the incisors. Also known as the premaxilla

Lacrimal Bone

-bone forming the medial aspect of the orbit (eye socket)

Mandibular Bone

-the horseshoe-shaped bone forming the lower jaw

Nasal Bone

-two bones forming the bridge of the nose

Palantine Bones

-bone that forms the hard palate

Vomer

-bone forming the base of the nasal septum

-septum is a partition

Zygomatic Bones

-bones forming the hard part of the cheek and the lower portion of the orbit

The Back Bones

-the vertebral and spinal column is composed of a sense

-based on size and function

Bones of the Thorax

-chest cavity made up of the ribs and sternum

-ribs attach to thoracic vertebrae; correspond w/ each other

-the sternum, or breastbone is along the midline of the chest and make up the ventral portion of the rib cage

3 portions of the Sternum

-upper portion of the sternum is called manubrium

-mid portion is called the body

-lower portion is called the xiphoid process

*as a landmark when taking abdominal radiographs and use it to determine where to stop shaving for abdominal surgery

The Appendicular Skeleton

-include bones of the front and rear limbs and bones of the limb girdles

The Thoracic Limb

Scapula

-a flat, triangular bone at the top of the shoulder commonly known as the shoulder blade

Clavicle

-aka collarbone; some animals have a reduced (imperfect) clavicle, while other species, completely lack one

-species capable of grasping w/ their front limbs posses one

ex: cats and primates

Humerus

-bone of the upper front limb between the shoulder and elbow

Radius

-one of two bones in the lower front limb between the elbow and wrist(carpus)

Ulna

-one of two bone in the lower front limb between the elbow and wrist

Olecranon

-bony process on the proximal aspect of the ulna

Carpals

-six to eight bones(depending on species) grouped together in two rows to make up the carpus

Metacarpals

-a group of long bones between the carpals and phalanges

Phalanges

-aka digits; each phalanx has 3 phalanges

The Pelvic Limb

Pelvis

-3 pair of bones: ilium, ischium, and pubis

Femur

-aka thigh bone

-femur is between the hip and stifle

Patella

-large sesamoid bone found in the stifle

-aka knee cap

Fabella

-sesamoid bone found in the back of the femoral condyles

-most species have two

Tibia

-the large medial bone of the lower hindlimb

Fibula

-the smaller lateral bone of the lower hindlimb

Tarsals

-seven bones that make up the tarsus(back)

Calcaneus

-one of the seven tarsal bones that sits in the back of the tarsus

-aka the heel bone

Metatarsals

-group of bones between the tarsus and the phalanges

Additional Bone Pathology Terms

Achondroplasia

-hereditary condition in which the bone and cartilage of limbs fail to grow to normal size

Amputation

-removal of a limb or other appendage

Calcification

-deposit of calcium salts in tissue

Callus

-bone deposit formed at the end of a bone fracture

-absorbed as fracture is required and then replace by true bone

Crepitation

-cracking sounds produced by the grating of broken

-aka crepitus

Decalsification

-loss of calcium salts in bone and teeth

Dislocation

-displacement of a bone from its joint

Fracture

-sudden breaking of nose

Herniation of IVD

-abnormal protrusion of an IVD into the neural cavity or spinal nerves

Kyphosis

-abnormal, increased, dorsal curvature of the spine

-aka hunchback

Lordosis

-downward or ventral curvature of the lumbar spine

-aka swayback

Laminectomy

-removal of part of the vertebral arch to relieve pressure from a rupture IVD

Othropedic

-branch of surgery dealing w/ the skeletal system

Osteoporosis

-decreased bone density due to loss of bone tissue

-bone becomes porous and fragile; caused by malnutrition

Reduction

-correction of a fracture

-open reductions(after incision) and closed reductions(w/o incision)