skeletal

• 1: the hardest substance
• 2:sits in a matrix

• osteocytes
• osteoblasts - create/build bone
• osteoclasts - destroy/remove bone
• (when bone is too thick)

secrete the matrix(collagen fiber embedded in a geletin - like substance). they then harden the matrix through a process of OSSIFICATION

bones act as a storage site for minerals (calcium)

• 1: calcitonin - thyroid gland
• 2: parathyroid - parathyroid gland

prevents hypercalcemia

prevents hypocalcemia

• 1:cancellous
• 2:compact

spongy bone, spaces between spicules are occupied by marrow. helps reduce weight of bone

very heavy, dense and strong. Makes up the shaft of long bones and the outside layer of all bones

they run lengthwise of bones. Each system has a haversian canal

contains blood vessels, lymph vessels and nerves to supply the bone cells (osteocytes)

tiny channels through the bone, allow osteocytes to contact eachother and exchange nutrients and get rid of wastes

the outer covering of all bones except articular (where muscles/tendons attatch) or joint surfaces. Composed of fibrous tissue and its inner layer contains bone forming cells (osteoblast)

lines the hollow interior of bones, also contains osteoblasts

blood vessels come in the bone matrix called the volkmans canal. They come in at right angles and contain blood vessels. Blood vessels in the VC join with blood vessels in the haversian system.(verticle) * how cells get nutrients

large blood vessels, along with lymph vessels and nerves also enter many large bones. These large vessels primarily carry blood into and out of the bone marrow. *can resemble a FX in the bone*

outer part of the bone/superficial part

replaces cartilage

• the shaft of the bone
• long bones = bone begins developing (primary growth plate)

• secondary growth center.
• portion of long bones that is at each end, below that is the epiphsyeal plate where growing takes place.
• the site where the creation of new bone allows the long bones to lengthen as the animal grows

develops from fibrous tissue members

• cartilage located between Diaphysis (shaft) and Epiphyses of bone
• *sites where new bone develops to allow long bones to lengthen*

• Osteoblasts replace cartilage with bone on the Diaphyseal surface of the place
• when the bone has reached its full size, the epiphyseal plate completely ossifies

• occurs in certain skull bones.
• bone forms in the fibous tissue membrane that covers the bottom in the developing fetus

• long
• short
• irregular
• flat

• most bones of the limbs
• have proximal and distal epiphysis
• consist primarily of cancellous bone covered by a thin layer of compact bone

• shaped like marshmellows or cubes
• the core consits of spongy bone covered by a thin layer of compact bone
• *carpal, tarsal bones*

• thin and flat
• cancellous bone sandwich
• 2 thin plates of compact bone with a layer of cancellous bone in the middle
• *skull and scapula*

• a truley irregular shape
• the vertebra, some of the skullbones are irregular
• sesemoid bones are included
• *patella = larges sesemoid bone*

• fills the spaces and specules of cancellous bone
• large spaces within the diaphyses

• *HEMATOPOIETIC*(forming)
• forms RBC
• makes up the majority of the bone marrow in young animals
• located in a select few spaces in adults - end of some long bones, interiors of the pelvic bone and sternum

• consists primarily of adipose connective tissue (fat)
• most common type of marrow in adult animals.
• does not produce blood cells
• *can revert to Red marrow if the body need it to*

• Joint surfaces
• smooth areas of compact bone where bones come in contact with eachother to form joints
• each articular surface is covered by articular cartilage (smooth, thin layer of hylaine cartilage)

• large, round articular surface (joint)
• *humerous, femur*

spherical articular surface on the proximal end of a long bone

• flat articular surface
• found in the carpal, tarsal joints, vertebrae and long bones such as the radius and ulna

• projections off a bone feature (lumps, bumps)
• rough, irregular surfaces where muscles and tendons attatch to
• the larger the process, the more powerful the muscular pull it will be
• name depends on the location

• Spinous - vertebrae
• Trochanter - femur
• Tiberosity - ischium
• Spine - scapula
• Wing - atlas

• Heads and Condyles are Articular processes
• *move with joints*
• Non-movement, non-articular processes are usually tendon (muscle) attatchment sites
• *don not move, attatched to muscle*

• Foramen
• Fossa

• a hole in a bone
• usually something important passes through it like a nerve or blood vessel
• * the OBTURATOR foramen only acts as a function to lighten the pelvis*

• a depressed or sunken area on the surface of a bone
• usually occupied by a muscle or tendon

• bones of the head and trunk
• skull,hyoid bone (neck region), the spinal column, the ribs and the sternum

• the most complex part of the skeleton
• most of the skull bones are united by jagged, immovale, fibrous joints called SUTURES
• the mandible is connected to the skull by a freely moveable synovial joint

• the cranium is the portion of the skull that surrounds the brain
• external bones are partially visible on the surface of an intact skull
• use them as landmarks

• from caudal to rostral
• 1-occipital bone (1)
• 2-interparietal bones (2)
• 3-parietal bones (2)
• 4-temporal bones (2)
• 5-frontal bones (2)

• single bone that forms the caudoventral portion of the skull
• it is the most caudal skull bone
• *it is where the spinal cord exits the skull*
• *it is the skull bone that articulates (forms a joint) with the first cervical vertebra*

• a large hole, FORAMEN MAGNUM is in the center of the occipital bone:where the spine exits the skull
• on either side of the foramen magnum are the OCCIPITAL CONDYLES

• two small bones located on the dorsal midline between the occipital bone and the parietal bones
• usually visible in young animals
• may fuse together into one bone or fuse to the parietal bones and become indesquisable in adults

• process on occipital bone for attatchment of nuchal ligament(assists in supporting head)
• *movement up and down*

• they form the dorsolateral walls of the cranium
• they are large and well developed in dogs,cats and humans
• *relatively small in horses and cattle*

• located below or ventral to the parietal bones
• they are important for several reasons:
• 1-form the lateral wall
• 2-contain the middle and inner ear structures
• 3-skull bones that form the tempromandibular joints (TMJ) with the mandible

the bony canal that leads into the middle and inner ear cavities

• form the forehead region
• located just rostral to the parietal bones
• form the rostrolateral portion of the cranium and a portion of the orbit
• a large Paranasal sinus, the frontal sinus is contained within the frontal bone

• the horned breeds of cattle, the cornual process of the frontal bone is the horn core around which the horn develops
• this process is hollow and communicates with the frontal sinus

• Sphenoid bone
• Ethmoid bone

• forms the ventral part of the cranium
• contains depression- THE PITUITARY FOSSA, that houses the pituitary gland
• located just rostral to the occipital bone
• contains a paranasal sinus called the SPHENOID SINUS

• single bone located just rostral to the sphenoid bone
• it contains the sievelike CRIBIFORM PLATE, through which the many branches of the OLFACTORY(sense of smell) nerve passes from the upper portion of the nasal cavity to the OLFACTORY BULB of the brain

• 3 tiny but important pairs of ear bones
• hidden away in the middle ear
• known as OSSICLES
• starting from outside: malleus or hammer, incus or anvil, stapes or sturrup

• transmit vibrations from the tympanic membrane across the middle ear cavity to an inner ear structure called the COCHLEA.
• in the COCHLEA, receptor cells for hearing convert the vibrations to nerve impulses that are interpreted by the brain as sound

• from rostral to caudal
• 1-incisive bones (2)
• 2-nasal bones (2)
• 3-maxillary bones (2)
• 4-lacrimal bones (2)
• 5-zygomatic bones (2)
• 6-mandible (1)

• sometimes called premaxillary bones
• the most rostral skull bones
• house the upper incisor teeth (except in ruminents)

• form the bridge of the nose, which is the dorsal part of the nasal cavity
• *size of the nasal bones will vary with breed*

long faced animals

short faced animals

• make up most of the upper jaw
• house the upper canine teeth, premolars and molars and the maxillary simuses
• along with the PALANTINE BONES, the maxillary bones form the hard palate
• form the rostral portion of the hard palate and the palantine bones from the caudal part

• form part of the medial portion of the orbit of the eye
• a space within each lacrimal bone houses the LACRIMAL SAC, which is part of the tear drainage system of the eye

• also known as malar bones
• they form a portion of the orbit of the eye and join with a process from the temporal bones to form the ZYGOMATIC ARCHES

• lower jaw
• houses all of the lower teeth
• the only moveable skull bone
• forms the TMJ with the temporal bone on each side
• in dogs, cats and cattle, the two sides of the mandible are seperate bones united by a cartiaginous joint, the MANDIBULAR SYMPHYSIS
• the symphysis is the weakest part of the mandible

In adult horses and swine, the two halves fuse together into one solid bone

• the two main regions of the mandible are the shaft and ramus
• shaft - house all the teeth (horizontal portion)
• ramus - caudal end, verticle portion, where the powerful jaw muscles attatch and where the articular condyles that form the TMJ's with the temporal bones are located

• Palantine bones (2)
• Pterygoid bones (2)
• Vomer boen (1)
• Turbinates (4)

make up the caudal portion of the hard palate (which seperates the mouth from the nasal cavity)

support part of the lateral walls of the pharynx

• located on the midline of the skull
• forms part of the NASAL SEPTUM, which is the cental "wall" between the L and R nasal passages

• also called the NASAL CONCHAE
• 4 thin, scroll like bones that fill most of the space in the nasal cavity
• each side has a dorsal and ventral turbinate
• they are covered by a moist, very vascular soft tissue lining of the nasal passages
• the scroll like shape forces air through the nose around many twists and turns as it passes through the nasal cavity
• helps warm and humidify the air, helps trap tiny particles of inhaled foreign body

• also called the HYOID APPARATUS
• looks somewhat like the letter H with its two legs bent back to form a U shaped structure
• located high in the neck, just above the larynx between the caudal ends of the mandible
• supports the base of the tongue, the pharynx and the larynx
• helps the animal swallow
• attatched to the temporal bone by two small rods of cartilage
• *SEPERATE BONE OF THE AXIAL SKELETON*

• also called the vertebral column
• made up of a series of irregular bones called vertebrae, that extend from the skull to the tip of the tail

• divided into 5 regions:
• 1-cervical
• 2-thorasic
• 3-lumbar
• 4-sacral
• 5-coccygeal

cat 7, dog 7, cattle 7, horse 7, goat 7, pig 7, sheep 7, human 7

cat 13, dog 13, cattle 13, horse 18, goat 13, pig 14-15, sheep 13, human 12

cat 7, dog 7, cattle 6, horse 6, goat 7, pig 6-7, sheep 6-7, human 5

cat 3, dog 3, cattle 5, horse 5, goat 5, pig 4, sheep 4, human 5

cat 5-23, dog 20-23, cattle 18-20, horse 15-21, goat 16-18, sheep 16-18, human 4-5

• a typical vertebrae consists of
• body
• arch (sometimes called the neural arch)
• group of processes

• it is the main, ventral portion of the bone
• it is the strongest, most massive portion
• the bodies of the adjacent vertebrae are seperated by the INTERVERTEBRAL DISCS (which act a little cartilagenous shock absorbers

• dorsal to the body
• when the arches of all the vertebrae line up, they form a long, flexible tunnel called the SPINAL CANAL, (which houses and protects the spinal cord)

• usually has some combination of 3
• the single dorsally projecting spinous process
• the two laterally projecting transverse process
• these act as sites for muscle attatchments and leverage to move the spine and trunk
• the articular processes are located on the cranial and caudal end of the vertebral arches and helps form the joins between adjacent vertebrae

• neck region
• the first two (2) cervical vertebrae are somewhat unusual in shape and have specific names
• C1- atlas
• C2 - axis

• has tow large, winglike processes called the WINGS OF THE ATLAS, that can be palpated
• the atlas has no vertebral body, it consists of a bony ring that the spinal cord passes through with the two (2) wings sticking out laterally

• just caudallyt o the atlas
• its most prominent feature is its large, bladelike spinous process that projecs up dorsally and the peglike dens fit into the caudal end of the atlas to help form the atlantoaxial joint

• dorsal to the thorax
• numbers can vary among species and can vary within a species
• usually the number of thorasic vertebrae is the same number of pairs of ribs
• the most characteristic feature is their tall, spinous processes and their lateral articular facets, which form joints with the heads of the ribs

• dorsal to the abdominal region
• numbers vary among species and can vary within a species
• the mose massive looking bones
• bodies are large and bulky (they have to support all the weight of the abdominal organs and structures without the aid of the ribs)

• unique
• fuse to form a single, solid structure called the SACRUM
• the number of vertebrae fused in the sacrum varies among species
• the sacrum is located dorsal to the pelvic region
• forms a joint with the pelvis on each side in what is called the SACROILIAC JOINT

• bones of the tail
• numbers vary between species but even within a species
• the first few coccygeal vertebrae have usual characteristics of vertebrae, such as bodies, arches and processes(toward the tip of the tail, they are reduced to simple little rods of bone)

• flat bones
• form the lateral walls of the thorax
• the number of pairs usually equals the number of thorasic vertebrae
• at the dorsal ends, the heads of the ribs form joints with the thorasic vertebrae
• these freely moveable joints help the process of ventilation
• byi swiveling the ribs at their dorsal ends, the ventilatory muscles can enlarge or diminish the size of the thorax
• the ventral ends of the ribs are a lot more variable
• each rib has 2 parts, dorsal = bone and ventral = cartilage

• rib = costal
• cartilaginous part = costal cartilage
• the junction with the bony part = costochondral junction
• the costal cartilages either directly join the sternum or join the costal cartilage ahead of them
• the ribs whose cartilage join the sternum = sternal ribs
• the ribs that join the adjacent costal cartilage = asternal ribs
• floating ribs = no attatchment , 2 on each side

• breastbone
• forms the floor of the thorax
• made up of a series of rod like bones = sternebrae
• *only the first and last sternebrae are named and used as landmarks*(the others are numbered from cranial to caudal
• the first = most cranial = manubrium
• the last = most caudal = Xiphoid or Xiphoid process
• Xiphoid cartilage extends from the xiphoid process and is easily felt

• made up of the bones of the main apendages
• front limbs = thoracic limbs
• hind limb = pelvic limb

• scapula
• humerus
• radius
• ulna
• carpal bones
• metacarpal bones
• phalanges

• pelvis = ilium, ischium, pubis
• femur
• tibia
• fibula
• tarsal bones
• metatarsal bones
• phalanges

• most proximal bone of the thoracic limb
• a flat, somewhat triangular bone with a prominent longitudal ridge on its lateral surface (spine)
• at its distal end, it forms the socket portion for the shoulder joint
• *this fairly shallow, concave articular surface is called the GLENOID CAVITY
• it is connected with the main body of the scapula by a narrowed area known as the NECK

• long bone of the upper are or BRACHIUM
• on its proximal end is the shoulder joint
• *head of humerus, which is joined to the shaft by a neck*
• opposite the head on the proximal end are some large processes called TUBERCLES, where the powerful muscles attatch

• the largest process is called the GREATER TURBERCLE
• the distal articular surfaces of the humerus are referred to collectively as the CONDYLE
• the medial articular surface is the TROCHLEA, which articulates with the ulna
• the lateral one is the CAPITULUM, which articulates with the radius
• just above the condyle on the back surface of the humerus is a deep indentation called the OLECRANON FOSSA
• the non articular "knobs" on the medial and lateral surfaces of the condyle are called the MEDIAL AND LATERAL EPICONDYLES*** LANDMARKS

• two bones form the forearm or ANTEBRACHIUM = ulna and radius
• the ulna forms a major portion of the elbow joint with the distal end of the humerus

• the large olecranon process forms the point of the elbow where the tendon of the powerful TRICEPS BRACHII muscles attatches
• the TROCHLEAR NOTCH is a half moon-shaped, concave articular surface that wraps around part of the humeral condyle to help make the elbow joint a tight, secure joint
• at the proximal end of the trochlear notch is a beak-shaped process known as the ANCONEAL PROCESS
• *when the elbow is extended, the anconeal process tucks into the olecranon fossa on the distal end of the humerus*

• at the distal end of the trochlear notch are the MEDIAL AND LATERAL CORONOID PROCESS(articulated with the radius)
• *in the horse, the ulna consists only of the proximal portion that joins with the radius about midshaft*
• in other species, the distal end of the ulna consists of a pointed process = STYLOID PROCESS, articulated with the carpus

• the main weight bearing bone of the ANTEBRACHIUM (forearm)
• on the proximal end, the radius has facets that articulate with the proximal end of the Ulna and a large, concave articular surface where it joins with the distal end of the humerus.
• at the distal end, the radius has several facets and a pointed process called the STYLOID PROCESS that articulates with the carpus

• two rows of carpal bones
• arranged parallel to each other in a proximal row and a distal row
• in horses, it is referred to as the KNEE
• the bones of the proximal row are given individual names: Radial carpal bone, Ulnar carpal bone, Accessory carpal bone- protruding backward on the lateral side of the carpus
• *some species also have an intermediate carpal bone*
• the bones of the distal carpal bones are given numbers, starting with the medial side and working laterally

• extend distally from the distal row of carpal bones to the proximal phalanges
• horses only have one metacarpal bone supporting their weight
• this large metacarpal bone = cannon bone
• the horse has 3 metacarpal bones in each leg, 1- large metacarpal bone, 2 - smaller vestigial metacarpal known as SPLINTS
• *the splint bones do not support any weight and only extend one half to two thirds of the way down the shaft of the large metacarpal*
• dogs and cats have 5 digits making up their front paws, numbered medial to lateral (1-5)
• metacarpal 1 = dewclaws
• cattle walk on 2 toes, 2 metacarpal bones (3 and 4) but these are fused into one single bone
• *a longitudinal groove running down the metacarpal bone clearly shows its tow bone origin*

• digit = toe
• each digit is made up of two or three bones called PHALANGES
• the phalanges are individual bones that make up the digits
• horses have one digit on each limb, composed of 3 phalanges and 3 sesamoid bones
• the phalanges are named accordingly
• 1-proximal phalanx -long pastern bone
• 2-middle phalanx - short pastern bone
• 3-distal phalanx - coffin bone
• also contains 3 sesamoid bones, 2 proximal and 1 distal

• irregular bones found in some tendons, where they change directions suddenly over the surface of joints
• sesamoid bones act as bearing over the joint surface to allow muscle to exert powerful forces on the bones without the tendons wearing out from the constant back and forth movements over the joint

• in the horse, the two PROXIMAL SESAMOID BONES are located behind the joint between the large metacarpal bone and the proximal phalanx in the large digital flexor tendons
• *this joint is known as the fetlock joint*
• in the horse, the distal sesamoid bone is located deep in the hoof behind the joint between the middle and distal phalanges, where the digital flexor tendon attatches to the distal phalanx
• *distal sesamoid bone = NAVICULAR BONE*

• they have 4 digits on each limb
• the 3rd and 4th support weight
• the 2nd and 5th are vestiges (called dewclaws)
• each contain one or two small bones that dont articulate with the rest of the bones of the foot

• 5 digits, dewclaws = 1
• digit 1 = 2 bones = proximal and distal phalanx
• digit 2 and 5 = 3 bones = proximal, middle and distal phalanx
• *each distal phalanx contains a pointed UNGUAL PROCESS that is surrounded by the claw*

directly connected to the axial skeleton through the sacroiliac joint that united the ilium of the pelvis with the sacrum of the spinal column

• starts developing as 3 seperate bones on each side that eventually fuse into a solid structure
• the two halves are jointed ventrally by a cartilagenous joint called the PELVIS SYMPHYSIS
• the pelvis joins the axial skeleton dorsally and the R and L Sacroiliac joints

• 1-ilium
• 2-ischium
• 3-pubis

• cranial-most bone of the pelvis
• it projects dorsocranial direction
• it is the bone that forms the sacroiliac joints with the scarum
• in dogs and cats, the smooth "wing" of the ilium projects forward and it is easily felt as a landmark
• in horses and cattle, the cranial end of the ilium on each side has large medial and lateral processes
• the TUBER SACRALE projects medially and joins with the sacrum to form the sacroiliac joint
• the TUBER COXAE projects laterally and is called the point of the hip

• the caudal most pelvic bone
• the main, rear projecting process of the ischium is the ischial tuberosity

• the smallest of the three bones
• located medially
• forms the cranial portion of the pelvic floor and the ischium forms the caudal part

• the 3 bones that make up each side of the pelvis come together at the socket portion of the ball and socket hip joint in a concave area called the ACETABULUM
• the ACETABULUM is a deep socket that tightly enclosed the head of the femur to form the quite stable hip joint

• 2 large holes located on either side of the pelvic symphysis
• nothing but a few small blood vessels and nerves pass through the OBTURATOR FORAMINA
• primary function is to lighten the pelvis

• long bone of the thigh
• on the proximal end is the ball portion of the ball and socket hip joint called the HEAD of the femur, which is attatched to the shaft by a neck
• the head of the femur is smalled and more spherical
• it normally fits very deeply and securely into the acetabulum of the pelvis
• opposite the head on the proximal end are some large processes, the trochanters, where strong hip and thigh muscles attatch*the largest one = the greater trochanter*

• the shaft of the femur is fairly straight and extends down to the distal end to form the stifle joint
• the three (3) articular surfaces on the distal end of the femur are the 2 condyles caudally and 1 trochlea cranially
• the medial and lateral condyles articulate with the condyles on the proximal end of the tibia
• the femur has non-articular "knobs" medial and lateral to the condyles = epicondyles

a smooth articular groove in which the patella rides

• largest sesamoid bone
• formed in the distal tendon of the large quadriceps femoris muscle on the cranial aspect of the stifle joint
• it helps protect the tendon as it passes down over the trochlea of the femur to insert on the tibial crest

• the medial and lateral fabellae = 2 small sesamoid bones located in the proximal GASTROCRIEMIUS or CALF MUSCLE tendons just above and behind the femoral condyles of dogs and cats
• *NOT IN CATTLE AND HORSES*

• the main weight bearing bone of the lower leg
• forms the stifle joint with the femur above and the hock with the tarsus below it
• when viewed from above, the proximal end of the tibia appears triangular with the apex of the triangle facing forward
• the tibial condyles on top of the proximal end aticulates with the condyles of the femur
• the forward facing point is the TIBIAL TUBEROSITY = TIBIAL CREST
• the patellar tendon attatches to the tibial tuberosity
• the shaft is triangular at the proximal end and fairly round distally
• at the distal end, the articular surface of the tibia consists of grooves that articulate with the tibial tarsal bone

palpable process, a "knob" on the medial side of our ankle at the distal end of the tibia

• thin but complete bone in dogs and cats
• parallel to the tibia
• consists of a proximal extremity, a shaft, a distal extremity
• does not support any significant weight
• maily serves as a muscle attatchment site
• in horses and cattle, only the proximal and distal end of the fibula are present *the shaft is not*
• at its distal end, the fibula forms a palpable process called the LATERAL MALLELOUS

• tarsus = ankle
• consists of 2 rows of short bones = tarsal bones
• the proximal row is named
• the distal row is numbered
• the two largest proximal tarsal bones 1- tibial tarsal bone, 2 - fibular tarsal bone, 3 - a smaller central tarsal bone is tucked behind the 2 larger bones
• the calcaneal tuberosity of the fibular tarsal bone projects upward and backward to form the point of the hock
• it acts as the point of attatchment for the tendon of the large GASTROCNEMIUS muscle and corresponds to our heal
• tarsal bones, numbered medial to lateral

• almost exactly to the metacarpal
• horses have a large metatarsal bone = cannon bone
• horses have 2 small metatarsal bones = the splint bones on each hind end

• the phalanges of the pelvic limb are almost exactly like the phalanges of the thoracic limb
• rear paws on dogs and cats = # 2 - 5

• the bones that form in soft organs or VISCERA
• 1- os cordis
• 2- os penis
• 3- os rostri

• a bone in the heart of cattle and sheep
• helps support the valves of the heart

• a bone in the penis of dogs, beavers, raccoons, and walruses
• partially surround the penile portion of the urethra
• the urethral groove on the ventral surface of the bone encloses the dorsal portion of the urethra

bone in the nose of swine that strenghens the snout for the rooting behavior of pigs

• junctions between bones
• some are completely immovable, some are moveable
• the immovable sutures that hold most of the skull bones together are joints

• Arthro and Articular = Joints
• Arthrology = the study of joints and the smooth bony surface that come together to form freely movable joint

• 3 general classifications of joints
• 1- immovable = fibrous joints
• 2- slightly movable = cartilaginous joints
• 3- freely movable = synovial joints

• SYNARTHROSES
• non movable joints
• bones are firmly united by fibrous tissue
• some examples = the sutures that unite most of the skull bones and fibrous union of the splint bones of horses with large metacarpal and metatarsal bones

• AMPHIARTHROSES
• slightly movable
• only capable of a rocking movement
• examples = intervertebral discs between the bodies of adjacent vertebrae in the spine and the symphysis between the two halves of the pelvis and mandible

• DIARTHROSES
• freely movable
• examples = shoulder and stifle joint

• share some common characteristics
• these include articular surfaces on the bones, articulate cartilage covering the articular surfaces and a fluid filled joint cavity enclosed by a JOINT CAPSULE
• firm connective tissue bands called ligaments may help stabilize the bones and hold the joint together

• very smooth joint surfaces of bones
• they consist of a smooth, thin layer of compact bone over the top of cancellous bone

• a thin, smooth layer of HYALINE cartilage that lies on top of the articular surface of a bone
• the articular cartilage functions like a teflon coating on the joint surfaces to aid the smooth movement between them to reduce friction

• bone to bone (like to like)
• bands of fibrous connective tissue that are present in and around many synovial joints

muscle to bone

• joint space
• fluid filled potential space between the joint surfaces
• a multi layered joint capsule surrounds it
• the outer layer is fibrous tissue
• the lining layer is called the SYNOVIAL MEMBTANE

• produces the synovial fluid that lubricates the joint surface
• the fluid is normally transparent and has the viscosity fo mediun-weight motor oil

• patellar ligament
• provides support on the front of the stifle joint

• flexion
• extension
• adduction = towards the body
• abduction = away from body
• circumduction

decreases the angle between two bones

increases the angle between two bones

movement of an extremity toward the medial plane

• movement away from the medial plane
• ABDUCT = take away

twisting movement of a part on its own axis

movement of an extremity so that the distal end moves in a circle

• Hinge joints
• gliding joints
• pivot joints
• ball and socket joints

• GINJLYMUS JOINTS
• one joint surface swivels around another
• the only movements possible are flexion and extension
• examples = elbow and atlantooccipital joint
• flexion and extension of the atlantoocipital joint moves the skull up and down in a noddin YES movement

• ARTHRODIAL JOINTS
• rocking joints
• the joint surface is relatively flat
• the movement between them is a rocking motion of one bone on the other, flexion and extension but adduction and abduction is possible
• example = carpus

• TROCHOID JOINTS
• one bone pivots or rotates on another
• the only movement is rotation
• example = atlantoaxial joint (the joint between the first and second cervical vertebrae
• the only movement allowed is the "no" movement

• SPHEROIDAL JOINTS
• allow the most extensive movements of all the joints
• allow all the synovial joint movements
• permit flexion, extension, abduction, adduction, rotation and circumduction
• examples = shoulder and hip