1. Skeletal System

2. What is it? Framework of structures Made of bones & cartilage
Supports & protects the body
Axial Skeleton
Includes skull, vertebrae, ribs, and sternum

3. Axial Skeleton Skull Vertebrae Many plates of bones fused together
Soft spot on top of skull
Fontanel
Vertebrae
Five distinct regions
Cervical
Thoracic
Lumbar
Sacral
Coccygeal

4. Cervical Vertebrae of the neck region
Atlas  called “C1”, the first cervical vertebra
Forms joint that lets you nod “yes”
Axis  called “C2”, the second cervical vertebra
Forms joint that lets you nod “no”
7 cervical vertebrae in all mammals

5. Thoracic
Vertebrae of the body region, always have a rib attached and a spine on top
“True ribs”
Directly attached to sternum with cartilage
“False ribs”
Connect to each other with cartilage, not the sternum
“Floating ribs”
Seen in the dog, have cartilage on the tips but do not attach to anything

6. Lumbar Vertebrae of the lower back
Carnivores tend to have more – greater flexibility
Herbivores need to have short, strong back to support large digestive and reproductive organs

7. Sacral Vertebrae of the pelvic region
Fused together on the ventral side
Herbivores generally have more to add strength & support to the back.
Carnivores less for flexibility

8. Coccygeal Vertebrae of the tail region Used for balance
Become smaller at the end of the tail

9. Appendicular Skeleton
The fore and hind limbs
Forelimb
Scapula- shoulder blade attached with muscle
Clavicle
Cat is the only domestic animal with a clavicle
Humerus
Forms the upper arm
Ulna
Forms the elbow joint, fused with the radius in herbivores

10. Appendicular Skeleton
Forelimb
Radius- forms the forearm
Carpus
Commonly called the “knee” in horses, the “wrist” in dogs and humans
Metacarpals- commonly called the cannon region of the forelimb

11. Appendicular Skeleton
Metacarpals
Number depends on species:
Humans: 5
Horses: 1 plus 2 accessory metacarpals, called splint bones
Dogs & Cats: 4 plus the dewclaw
Cattle: 1 that splits at bottom into a cloven hoof & 2 dewclaws
Pigs: 4 (2 toes & 2 dewclaws)

12. Appendicular Skeleton
Forelimb
Proximal phalanx (P1)
Bones of the finger, hoof, and claw
Intermediate phalanx (P2)
Distal phalanx (P3)
The coffin bone in horses
Proximal sesamoids
Tucked in behind P1
Distal sesamoid
Tucked in underneath P3

13. Appendicular Skeleton
Hind Limb
Pelvis
Tuber coxae-part of pelvis that forms the “point of hip”
Ischiatic tuberosity-part of pelvis that forms the “seat bones”
Femur
Patella
Forms the “stifle” joint in horses, knee in dogs or humans
Tibia
Main bone of the gaskin of the horse

14. Appendicular Skeleton
Hind Limb
Fibula
Fused with the tibia & considered vestigial in herbivores
Tarsus
Commonly called “hock”
Human ankle
Metatarsal
Cannon region in the hind limb. Number depends on species P1 P2 P3
Proximal & distal sesamoids

15. Axial and Appendicular Skeleton
Axis
Vertebrae
Skull
Cervical
Sacral
Thoracic
Lumbar
Coccygeal
Atlas
Scapula
Pelvis
Femur
Patella
Humerus
Ribs
Olecranon
Fibula
Tibia
Radius
Tarsals
Carpals
Metatarsals
Ulna
Phalanges
Phalanges
Sesamoids
Metacarpals

16. Classification of Bones
Short Bone
Cube shaped (carpus & tarsus)
Flat Bone
Plate of bone (scapula, rib, skull)
Irregular Bone
Complex shaped (vertebrae)
Sesamoid
Small, seed-shaped bone (proximal & distal sesamoids, patella)
Long Bone
Bone is longer than it is wide (femur, tibia, humerus)

17. Bone Anatomy Diaphysis Epiphysis Metaphysis Medullary Cavity Endosteum
Body of a long bone
Epiphysis
Enlarged ends of long bones
Metaphysis
Joining point of diaphysis & epiphysis
Medullary Cavity
Space within bone filled with marrow
Endosteum
Thin inner protective layer lining the medullary cavity

18. Bone Anatomy Epiphysis Diaphysis Periosteum Medullary cavity Endosteum
Bone marrow
Metaphysis

19. Bone Growth Occurs in the epiphysis of long bones
Epiphyseal growth plates produce cartilage, which gradually turns into bone via a process called ossification.

20. Fractures Simple Compound Complete Incomplete Bone does not break skin
Bone breaks through skin, much more serious
Complete
Fracture goes completely across the bone.
Incomplete
Fracture does not go completely across bone.

21. Classifying Fractures
Fissure fracture
Incomplete break, along the long axis of the bone
Greenstick fracture
Incomplete break on one side of a bone, usually due to a bending force
Transverse fracture
Break across the bone
Comminuted fracture
Bone shatters into many pieces

22. Bone Fractures
Fissured
Greenstick
Transverse
Comminuted