Equine Skeletal SystemBy Jess and Keara
What bones are made of?
Periosteum fibrous membrane rich in blood vessels
that envelopes the bone, except at the articular surfaces; it contributes especially to the bone’s growth in thickness.
*(articular surface= the surface of a joint at which the ends of the joint meet)
Compact Bone dense bone tissue composed of osteons, which resist pressure and shocks and protect the spongy tissue; it forms especially the diaphysis of the long bones.
Haversian Canal
Elementary cylindrical structure of the compact bone made up of four to 20 concentric bone plates that surround the Haversian canal.
Lengthwise central canal of the osteon. It encloses blood vessels and nerves.
Osteon
Spongy Bone Tissue made of bony compartments
separated by cavities filled with bone marrow, blood vessels and nerves
This structure gives bones their lightness.
Medullary Cavity Cylindrical central cavity of the bone
containing the bone marrow Encloses lipid-rich yellow bone marrow
Soft substance contained in bone cavities, producing blood cells; marrow is yellow in the long bones of
adults.
Bone Marrow
Volkmann’s Canal Transverse canals of the compact bone
enclosing blood vessels and nerves; Connect the Haversian canals with each other
and with the medullary cavity and the periosteum
Blood Vessel Channel in the bone through which the blood
circulates, carrying the nutrients and mineral salts the bone requires
Articular Cartilage Smooth resistant elastic tissue
covering the terminal part of the bone where it articulates with another bone
it facilitates movement and absorbs shocks
Connective Tissue
Ligaments
Link bones Sheets of strong, fibrous connective
tissue Identical to tendons in muscular
system Only difference is there function Ligaments attach bone to bone and tendons attach muscle to bone
Cushioning… Cartilage Smooth resistant elastic tissue
covering the terminal part of the bone where it articulates with another bone
it facilitates movement and absorbs shocks
Synovial Fluid› Small membranous sacks that
contain fluid and rest between bones of a joint, i.e., above coffin bone
› Helps to cushion and absorb shock
Joints
Types Fibrous
Cartilagenous
Synovial
Fibrous Immoveable!
Ex, plates in skull
Cartilagenous Partially moveable
Connected by cartilage
Ex, joints between vertebrae
Synovial Completely moveable Hinge
› Joint between 3rd metacarpal and long pastern
Ball and Socket› Joint between ilium and femur (hip joint)
Can you name the bones?
We’ll see…
Skull
What makes up the mouth…
Premaxilla (incisive bone)› Holds alveoli for upper incisive teeth
Maxilla› Holds alveoli for molar and premolar teeth
Mandible (lower jaw)› Holds alveoli for all teeth of lower jaw
And all the rest….
Bones of the Middle Ear
Malleus ~ Hammer
Incus ~ Anvil
Stapes ~ Stirrup
Spine1. Cervical vertebrae2. Thoracic vertebrae3. Lumbar vertebrae4. Sacrum5. Coccygeal/ caudal vertebrae
Cervical Vertebrae Make up the neck of the horse 1st cervical vertebrae = Atlas 2nd cervical vertebrae = Axis
› Allows neck to flex and rotate
Thoracic Vertebrae 18 Characteristically have high spines 3rd and 4th form the withers
Lumbar Vertebrae 6 Characteristically long and flat
Sacrum
Coccyx
Made up of 6 sacral vertebrae fused together(*not mentioned in video but comes right after lumbar vertebrae and before the caudal)
Made up of 15-21 coccygeal Vertebrae. (More commonly known as the Caudal Vertebrae.)
Ribs and Sternum 18 pairs of ribs First 8 pairs connect to the sternum Sternum ~ breast bone
› Made up of 6-8 sternebrae and cartilage
Foreleg
Shoulder bones connected to the….
Scapula
Humerus
Radius
Ulna (not functional in a horse)
From the wrist distally… Carpus
› Forms what is commonly called the knee in a horse
Metacarpus› 3rd metacarpal, or cannon bone, is the
only functional metacarpal Splint bones – 2nd and 4th metacarpal
› Small bones running parallel to the cannon bone on either side
*** splints is a condition when a splint bone sustains a fraction
Fingers???
Technically referred to as phalanges 1st Phalange ~ Proximal Phalanx ~
Long Pastern 2nd Phalange ~ Middle Phalanx ~ Short
Pastern 3rd Phalange ~ Distal Phalanx ~ Coffin
Bone
Can you name them?
Hind Leg
Pelvic Girdle Os Coxae ~ half of the pelvic girdle
› 3 bones Ilium Ischium Pubis
Hip bone’s connected to the …
Femur Patella ~ knee cap Crus = Fibula + Tibia
› Fibula isn’t functional; fuses along the length of the tibia
Now you know the bones…
…Can you name all 205-210 of them?
While you were learning all about the bones of a horse, did you notice any similarities between a horse’s
skeleton and a humans?
Here are just a few… We have almost the exact number of
bones as horses Horses’ forelegs are almost identical to
our arms in position, the only real difference being the elongation of the bones that make up our wrist, hand and fingers in the horses’ knee, lower leg (cannon), ankle and hoof
Differences The main differences between a horse’s skeleton
and a human’s skeleton come from a horse being a quadraped while humans are bipeds
This changes the angle of the limbs in relation to the spine, the length of the neck, and the shape of the head
Horses’ being prey animals and humans predators also affects the skull; a horse’s orbits are laterally positioned because they are monocular, and their jaw is longer to provide for the powerful molars they use to chew their fibrous diet
theend
OH MY BONES!!!!!!!!!!
………XD
Sources http://visual.merriam-webster.com/hum
an-being/anatomy/skeleton/structure-long-bone.php
http://www.besthealth.com/besthealth/bodyguide/reftext/html/skel_sys_fin.html#joints
http://www.teachpe.com/anatomy/joints.php
http://www.yourveterinaryclinic.com/page7/page8/skeleton-horse.html
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