1. Equine Skeletal system

2. Objectives List the components of the skeletal system
Label the divisions of the vertebral column
Label the bones of the skull
Label the bones of the appendicular skeleton
Foreleg and hind leg
List and describe three types of joints
Label the joints of the leg (fore and rear)

3. Surface Planes of the horse
Caudal- The plane going towards the hindend. The rear portion. Cranial- The plane going towards the head end (front). The front portion
Distal- Further away from the main part of the body, furthest. Example: The hoof is the most distal part of the leg.
Dorsal- Back surface or topline
Lateral- Away from the median (middle line) plane. It is also the outside or external surface.
Medial- Towards the middle (median plane) of the body. The inner or more internal part.
Palmer- The sole (bottom) of the front hoof continuing up to the back of the knee (carpus)
Plantar- The sole of the hind hoof continuing up to the back of the hock (tarsus)
Proximal- Closer to the body, or point of attachment. Example: The knee is proximal to the ankle
Rostral- Towards the nose
Ventral- Underneath or belly side

4. Axial Skeleton contains bones in the trunk area.
Skull
Spine (Vertebral column)
Ribs
Breastbone (Chest cavity)
Pelvis
Tail

6. Skull bones – flat, irregular in shape
Forms framework for the brain, mouth, eyes & nasal cavity.
Vertebral column – flexible column of small bones (vertebrae)
Hip bones – two large flat bones attached to the spine and sacrum that forms the pelvis or pelvic girdle
Ribs & Breastbone (Sternum) along with thoracic vertebrae form the chest cavity

7. Bones of the skull (fig. 5-4)
Temporal
Frontal
Nasal
Parietal
Zygomatic arch
Maxilla
Mandible

8. Appendicular Skeleton – forelegs and hindlegs used for locomotion, defense and feeding
Forelegs – connected to axial skeleton by muscles, not skeletal attachments
Hindlegs – attached to pelvis at the hip joint

9. Foreleg

10. Rear leg

11. Vertebral Bones (fig. 5-5)
7 Cervical vertebrae
18 thoracic
6 lumbar
5 sacral
15 – 21 coccygeal (tail)

13. Ribs and sternum 18 pairs of ribs
7 – 8 bony segments connected by cartilage make up the sternum

14. Types of joints A joint is the union of two or more bones:
1. Immovable joint: bones are directly connected by cartilage or fused and permit no movement
Example: bones of the cranium
2. Slightly moveable joint: joined by a pad of cartilage that adheres to both bones.
Vertebrae
Ribs to vertebrae

15. Types of Joints
3. Freely moveable joints: “True joints” allow range of movement. Bones are held together by ligaments that pass from one bone to another
Ends of bones are covered in smooth cartilage: articular cartilage
Absorbs shock and provides cushion, provides for smooth bearing
Entire joint is enclosed in fibrous sac: joint capsule
Inner surface of capsule – synovial membrane
Contains synovial fluid, lubricant

16. Joints of the foreleg (from top downward:
Shoulder: formed by scapula and humerus
Elbow: formed by humerus
Knee: formed by radius. carpal bones, and three metacarpal bones, splints and cannon bones
Fetlock: formed by cannon, two seismoid bones and the first phalanx (long pastern)
Pastern: formed by first and second phalanges (long and short Pastern)
Coffin: formed by second phalange (coffin bone)and navicular bone.

17. Joints of the rear leg (from top downward
Hip: formed from the pelvis and femur
Stifle: formed from the femur, tibia and fibula
Hock: formed by the tibia, tarsals (hock bone) and the metatarsals (splint and cannon bone).
Fetlock: formed by cannon, two seismoid bones and the first phalanx (long pastern)
Pastern: formed by first and second phalanges (long and short Pastern)
Coffin: formed by second phalange (coffin bone) and navicular bone.