Equine Skeletal
system
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)
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
Axial Skeleton contains bones in the
trunk area.

Skull

Spine (Vertebral column)

Ribs

Breastbone (Chest cavity)

Pelvis

Tail
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
Bones of the skull (fig. 5-4)

Temporal

Frontal

Nasal

Parietal

Zygomatic arch

Maxilla

Mandible
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
Foreleg
Rear leg
Vertebral Bones (fig. 5-5)

7 Cervical vertebrae

18 thoracic

6 lumbar

5 sacral

15 – 21 coccygeal (tail)
Ribs and sternum

18 pairs of ribs

7 – 8 bony segments connected by cartilage make up the sternum
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
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
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.
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.