1. bone is what
    • 1: the hardest substance
    • 2:sits in a matrix
  2. bone cells
    • osteocytes
    • osteoblasts - create/build bone
    • osteoclasts - destroy/remove bone
    • (when bone is too thick)
  3. what do osteoblasts do
    secrete the matrix(collagen fiber embedded in a geletin - like substance). they then harden the matrix through a process of OSSIFICATION
  4. Storage with bones
    bones act as a storage site for minerals (calcium)
  5. which 2 hormones are stored in the bone
    • 1: calcitonin - thyroid gland
    • 2: parathyroid - parathyroid gland
  6. what does calcitonin do
    prevents hypercalcemia
  7. what does parathyoid hormone do
    prevents hypocalcemia
  8. what are the two forms of bone structure
    • 1:cancellous
    • 2:compact
  9. what is cancellous bone
    spongy bone, spaces between spicules are occupied by marrow. helps reduce weight of bone
  10. what is compact bone
    very heavy, dense and strong. Makes up the shaft of long bones and the outside layer of all bones
  11. Haversian System
    they run lengthwise of bones. Each system has a haversian canal
  12. Haversian Canal
    contains blood vessels, lymph vessels and nerves to supply the bone cells (osteocytes)
  13. Canaliculi
    tiny channels through the bone, allow osteocytes to contact eachother and exchange nutrients and get rid of wastes
  14. Periosteum
    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)
  15. Endosteum
    lines the hollow interior of bones, also contains osteoblasts
  16. Volkmans Canal
    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
  17. Nutrient foramina
    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*
  18. Cortex
    outer part of the bone/superficial part
  19. Endochondral Bone Formation
    replaces cartilage
  20. Diaphysis
    • the shaft of the bone
    • long bones = bone begins developing (primary growth plate)
  21. Epiphysis
    • 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
  22. Intramembranous Bone Formation
    develops from fibrous tissue members
  23. Epiphyseal Plates
    • cartilage located between Diaphysis (shaft) and Epiphyses of bone
    • *sites where new bone develops to allow long bones to lengthen*
  24. Epiphyseal plate
    • 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
  25. Intramembranous Bone
    • occurs in certain skull bones.
    • bone forms in the fibous tissue membrane that covers the bottom in the developing fetus
  26. Bone Shapes
    • long
    • short
    • irregular
    • flat
  27. Long bones
    • most bones of the limbs
    • have proximal and distal epiphysis
    • consist primarily of cancellous bone covered by a thin layer of compact bone
  28. Short Bones
    • shaped like marshmellows or cubes
    • the core consits of spongy bone covered by a thin layer of compact bone
    • *carpal, tarsal bones*
  29. Flat 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*
  30. Irregular Bones
    • a truley irregular shape
    • the vertebra, some of the skullbones are irregular
    • sesemoid bones are included
    • *patella = larges sesemoid bone*
  31. Bone Marrow
    • fills the spaces and specules of cancellous bone
    • large spaces within the diaphyses
  32. Red Bone Marrow
    • *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
  33. Yellow Bone Marrow
    • 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*
  34. Articular Surfaces
    • 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)
  35. Condyle
    • large, round articular surface (joint)
    • *humerous, femur*
  36. Head
    spherical articular surface on the proximal end of a long bone
  37. Facet
    • flat articular surface
    • found in the carpal, tarsal joints, vertebrae and long bones such as the radius and ulna
  38. Processes
    • 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
  39. Processes cont'
    • Spinous - vertebrae
    • Trochanter - femur
    • Tiberosity - ischium
    • Spine - scapula
    • Wing - atlas
  40. Processes cont' 2
    • 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*
  41. Holes and Depressed areas
    • Foramen
    • Fossa
  42. Foramen
    • 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*
  43. Fossa
    • a depressed or sunken area on the surface of a bone
    • usually occupied by a muscle or tendon
  44. Axial Skeleton
    • bones of the head and trunk
    • skull,hyoid bone (neck region), the spinal column, the ribs and the sternum
  45. Skull
    • 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
  46. External bones of the caranium
    • 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
  47. External bones of the cranium cont'
    • from caudal to rostral
    • 1-occipital bone (1)
    • 2-interparietal bones (2)
    • 3-parietal bones (2)
    • 4-temporal bones (2)
    • 5-frontal bones (2)
  48. Occipital Bones
    • 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*
  49. Occipital Bone cont'
    • 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
  50. Interparietal Bones
    • 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
  51. Nuchal Crest
    • process on occipital bone for attatchment of nuchal ligament(assists in supporting head)
    • *movement up and down*
  52. Parietal Bones
    • 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*
  53. Temporal Bones
    • 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
  54. External Acoustic Meatus
    the bony canal that leads into the middle and inner ear cavities
  55. Frontal Bones
    • 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
  56. Frontal Bones cont'
    • 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
  57. Internal bones of the cranium
    • Sphenoid bone
    • Ethmoid bone
  58. Sphenoid 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
  59. Ethmoid Bone
    • 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
  60. Bones of the ears
    • 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
  61. Function of the ear bones
    • 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
  62. External Bones of the Face
    • 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)
  63. Incisive bones (2)
    • sometimes called premaxillary bones
    • the most rostral skull bones
    • house the upper incisor teeth (except in ruminents)
  64. Nasal bones (2)
    • form the bridge of the nose, which is the dorsal part of the nasal cavity
    • *size of the nasal bones will vary with breed*
  65. Dolichocephalic
    long faced animals
  66. Brachycephalic
    short faced animals
  67. Maxillary bones (2)
    • 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
  68. Lacrimal bones (2)
    • 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
  69. Zygomatic bones (2)
    • 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
  70. Mandible
    • 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
  71. Mandibular symphysis
    In adult horses and swine, the two halves fuse together into one solid bone
  72. Mandible cont'
    • 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
  73. Internal Bones of the Face
    • Palantine bones (2)
    • Pterygoid bones (2)
    • Vomer boen (1)
    • Turbinates (4)
  74. Palantine bones (2)
    make up the caudal portion of the hard palate (which seperates the mouth from the nasal cavity)
  75. Pterygoid bones (2)
    support part of the lateral walls of the pharynx
  76. Vomer bone (1)
    • 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
  77. Turbinates (4)
    • 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
  78. Hyoid bone
    • 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
  79. Spinal Column
    • 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
  80. Spinal Column cont'
    • divided into 5 regions:
    • 1-cervical
    • 2-thorasic
    • 3-lumbar
    • 4-sacral
    • 5-coccygeal
  81. Cervical spine
    cat 7, dog 7, cattle 7, horse 7, goat 7, pig 7, sheep 7, human 7
  82. Thorasic spine
    cat 13, dog 13, cattle 13, horse 18, goat 13, pig 14-15, sheep 13, human 12
  83. Lumbar spine
    cat 7, dog 7, cattle 6, horse 6, goat 7, pig 6-7, sheep 6-7, human 5
  84. Sacral spine
    cat 3, dog 3, cattle 5, horse 5, goat 5, pig 4, sheep 4, human 5
  85. Coccygeal spine
    cat 5-23, dog 20-23, cattle 18-20, horse 15-21, goat 16-18, sheep 16-18, human 4-5
  86. Vertebrae Characteristics
    • a typical vertebrae consists of
    • body
    • arch (sometimes called the neural arch)
    • group of processes
  87. Body of Vertebrae
    • 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
  88. Arch of Vertebrae
    • 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)
  89. Processes of the Vertebrae
    • 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
  90. Cervical Vertebrae
    • neck region
    • the first two (2) cervical vertebrae are somewhat unusual in shape and have specific names
    • C1- atlas
    • C2 - axis
  91. C1- Atlas
    • 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
  92. C2- axis
    • 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
  93. Thorasic Vertebrae
    • 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
  94. Lumbar Vertebrae
    • 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)
  95. Sacral Vertebrae
    • 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
  96. Coccygeal Vertebrae
    • 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)
  97. Ribs
    • 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
  98. Ribs cont'
    • 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
  99. Sternum
    • 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
  100. Appendicular Skeleton
    • made up of the bones of the main apendages
    • front limbs = thoracic limbs
    • hind limb = pelvic limb
  101. Thoracis limbs
    • scapula
    • humerus
    • radius
    • ulna
    • carpal bones
    • metacarpal bones
    • phalanges
  102. Pelvic limbs
    • pelvis = ilium, ischium, pubis
    • femur
    • tibia
    • fibula
    • tarsal bones
    • metatarsal bones
    • phalanges
  103. Scapula
    • 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
  104. Humerus
    • 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
  105. Humerus cont'
    • 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
  106. Ulna
    • 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
  107. Ulna Proximal end
    • 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*
  108. Ulna Distal end
    • 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
  109. Radius
    • 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
  110. Carpal Bones
    • 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
  111. Metacarpal Bones
    • 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*
  112. Phalanges
    • 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
  113. Sesamoid Bones
    • 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
  114. Phalanges and Sesamoid cont'
    • 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*
  115. Phalanges and sesamoid bones in cattle
    • 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
  116. Phalanges and Sesamoid bones in dogs and cats
    • 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*
  117. Pelvic limb
    directly connected to the axial skeleton through the sacroiliac joint that united the ilium of the pelvis with the sacrum of the spinal column
  118. Pelvis
    • 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
  119. Main regions of the Pelvis
    • 1-ilium
    • 2-ischium
    • 3-pubis
  120. Ilium
    • 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
  121. Ischium
    • the caudal most pelvic bone
    • the main, rear projecting process of the ischium is the ischial tuberosity
  122. Pubis
    • the smallest of the three bones
    • located medially
    • forms the cranial portion of the pelvic floor and the ischium forms the caudal part
  123. Pelvis cont'
    • 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
  124. Obturator Foramina
    • 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
  125. Femur
    • 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*
  126. Femur cont'
    • 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
  127. Trochlea
    a smooth articular groove in which the patella rides
  128. Patella
    • 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
  129. Fabellae
    • 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
  130. Tibia
    • 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
  131. Medial Malleous
    palpable process, a "knob" on the medial side of our ankle at the distal end of the tibia
  132. Fibula
    • 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
  133. Tarsal Bones
    • 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
  134. Metatarsal Bones
    • 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
  135. Phalanges of the pelvic limbs
    • the phalanges of the pelvic limb are almost exactly like the phalanges of the thoracic limb
    • rear paws on dogs and cats = # 2 - 5
  136. Visceral Skeleton
    • the bones that form in soft organs or VISCERA
    • 1- os cordis
    • 2- os penis
    • 3- os rostri
  137. Os Cordis
    • a bone in the heart of cattle and sheep
    • helps support the valves of the heart
  138. Os Penis
    • 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
  139. Os Rostri
    bone in the nose of swine that strenghens the snout for the rooting behavior of pigs
  140. Joints
    • junctions between bones
    • some are completely immovable, some are moveable
    • the immovable sutures that hold most of the skull bones together are joints
  141. Joint Terminology
    • Arthro and Articular = Joints
    • Arthrology = the study of joints and the smooth bony surface that come together to form freely movable joint
  142. Types of Joints
    • 3 general classifications of joints
    • 1- immovable = fibrous joints
    • 2- slightly movable = cartilaginous joints
    • 3- freely movable = synovial joints
  143. Fibrous Joints
    • 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
  144. Cartilaginous Joints
    • 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
  145. Synovial Joints
    • freely movable
    • examples = shoulder and stifle joint
  146. Synovial Joint Characteristics
    • 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
  147. Articular Surfaces
    • very smooth joint surfaces of bones
    • they consist of a smooth, thin layer of compact bone over the top of cancellous bone
  148. Articular Cartilage
    • 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
  149. Ligaments
    • bone to bone (like to like)
    • bands of fibrous connective tissue that are present in and around many synovial joints
  150. Tendons
    muscle to bone
  151. Joint Cavity
    • 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
  152. Synovial Membrane
    • produces the synovial fluid that lubricates the joint surface
    • the fluid is normally transparent and has the viscosity fo mediun-weight motor oil
  153. Patellar tendon
    • patellar ligament
    • provides support on the front of the stifle joint
  154. Synovial Joint Movements
    • flexion
    • extension
    • adduction = towards the body
    • abduction = away from body
    • circumduction
  155. Flexion
    decreases the angle between two bones
  156. Extension
    increases the angle between two bones
  157. Adduction
    movement of an extremity toward the medial plane
  158. Abduction
    • movement away from the medial plane
    • ABDUCT = take away
  159. Rotation
    twisting movement of a part on its own axis
  160. Circumduction
    movement of an extremity so that the distal end moves in a circle
  161. Types of Synovial Joints
    • Hinge joints
    • gliding joints
    • pivot joints
    • ball and socket joints
  162. Hinge 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
  163. Gliding 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
  164. Pivot Joint
    • 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
  165. Ball and Socket 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
Card Set
a and p of the skeletal system