Skeletal System of the Horse

SKELETAL SYSTEM OF THE HORSE

Equine Science

The Horse’s Skeletal System

Approximately 210 bones Gives shape to the horse Provides protection for the internal

organs Combines with the muscular system to

create movement Stores needed minerals Site of blood cell manufacturing Stores fat (adults)

The Horse’s Skeletal System

Bones classified as either: Long: support body weight & aid movement

limbs Short: aid in shock absorption

Knee & hock Flat: enclose vital organs

Ribs Scapula Some skull bones

Irregular: unpaired bones Vertebrae Some skull bones

The Horse’s Skeletal System

Two Parts Axial Skeleton--The trunk

Skull Vertebral Column Ribs Breastbone or Sternum Pelvis Tail

Appendicular Skeleton—The limbs Forelegs or Thoracic limbs Hind legs or Pelvic limbs

Axial Skeleton Vertebral Column

Average of 54 bones Divided into 5 parts

Cervical (neck)—7 vertebrae Thoracic (back)—18 vertebrae Lumbar (loin)—6 vertebrae (sometimes 5) Sacral (croup)—5 vertebrae (fused together) Coccygeal (tail)—15-21 vertebrae

Bound together with ligaments and cartilage

Axial Skeleton Hip Bones

Connected to the vertebral column at the sacrum

Sternum Canoe-shaped Connects to the ribs by cartilage Floor of chest cavity

Ribs 18 pairs Attached to the thoracic vertebrae

Axial Skeleton Skull

Attached to 1st vertebrae of the spine Foramen magnum—large opening through

which the spinal cord passes Two Parts

Cranium—surrounds the brain Face—encloses entrances to digestive and

respiratory systems Together form eye and nasal cavities

Appendicular Skeleton Forelimbs

No skeletal attachment to axial skeleton Connection is by muscles Support 60% of horse’s weight Many bones similar to human arms

Hind legs Attached to axial skeleton at the hip joints Move horse forward Similar to human legs

Joints Union of two or more bones or cartilages Three types

Immovable Permit no movement Connective tissue or fused bone Example: cranium bones

Slightly movable Pad of cartilage allows slight movement Example: vertebrae

Freely movable Joint cavity exists between two surfaces Bones held by ligaments

Slight degree of elasticity & limited blood supply Heal slowly and often imperfectly

Example: legs