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==Introduction==  

==Introduction==  

For general skeletal anatomy, follow links in blue. The following section will concentrate on anatomy specific to the horse.

The following section will concentrate on anatomy specific to the horse. For general skeletal anatomy, follow links in blue. In anatomical planes we use the term palmar for forelimb and plantar for hindlimb. These terms are all interchangable depending on whether you are referring to the fore or hindlimb.

==Thoracic Limb==

==Thoracic Limb==

The '''lesser and greater tubercles''' on the lateral and medial sides of the proximal humerus, respectively, are almost equally well developed. Both tubercles divided into two parts (cranial and caudal). The tubercles are separated by an '''intertubercular groove''', which is wide and has a central saggital ridge ('''intermediate tubercle'''). This ridge fits into a depression on the deep surface of the [[Muscles of the Elbow- Horse Anatomy#Flexors|biceps tendon]] and restricts movement of the tendon relative to the humerus in the standing horse.

The '''lesser and greater tubercles''' on the lateral and medial sides of the proximal humerus, respectively, are almost equally well developed. Both tubercles divided into two parts (cranial and caudal). The tubercles are separated by an '''intertubercular groove''', which is wide and has a central saggital ridge ('''intermediate tubercle'''). This ridge fits into a depression on the deep surface of the [[Muscles of the Elbow- Horse Anatomy#Flexors|biceps tendon]] and restricts movement of the tendon relative to the humerus in the standing horse.

The body of the bone bears the '''teres major tuberosity''' on its medial surface and the '''deltoid tuberosity''', which is opposite, on the lateral surface.

The body of the bone bears the '''teres major tuberosity''' on its medial surface and the '''deltoid tuberosity''', which is opposite, on the lateral surface.

The distal end forms a cylindrical '''condyle''' that transfers weight to the radius. On the lateral aspect of the condyle there is a small '''saggital ridge''' with grooves to allow articulation with the radius and ulna. The medial and lateral '''epicondlyes''' and '''lateral supracondylar crest''' are palpable landmarks. A shallow '''radial fossa''' is just proximal to the condyle on the cranial surface. The deeper '''olecranon fossa''', between the two epicondyles, lies opposite the radial fossa on the caudal surface. There is no supratrochlear foramen between the two fossae in horses.

The distal end forms a cylindrical '''condyle''' that transfers weight to the radius. On the lateral aspect of the condyle there is a small '''saggital ridge''' with grooves to allow articulation with the radius and ulna. The medial and lateral '''epicondyles''' and '''lateral supracondylar crest''' are palpable landmarks. A shallow '''radial fossa''' is just proximal to the condyle on the cranial surface. The deeper '''olecranon fossa''', between the two epicondyles, lies opposite the radial fossa on the caudal surface. There is no supratrochlear foramen between the two fossae in horses.

===[[Forelimb - Anatomy & Physiology#Radius and Ulna|Radius and Ulna]]===

===[[Forelimb - Anatomy & Physiology#Radius and Ulna|Radius and Ulna]]===

===[[Forelimb - Anatomy & Physiology#Metacarpals and Metatarsals|Metacarpals and Metatarsals]]===

===[[Forelimb - Anatomy & Physiology#Metacarpals and Metatarsals|Metacarpals and Metatarsals]]===

Horses are '''perissodactyl''' '''unguligrade''' animals. Unguligrade means that horses bear their weight on a horny covering (hoof) that surrounds their distal phalanx, perissodactyl means that they have only one weightbearing digit. They are virtually identical in their structure in the hindlimb and forelimb. The main differences are that in the forelimb they have metacarpals and the metacarpophalangeal joint, the hindlimb equivalents are the metatarsals and the metatarsophalangeal joint. Also in anatomical planes we use the term palmar for forelimb and plantar for hindlimb. These terms are all interchangable in the below article depending on whether you are referring to the fore or hindlimb.

Horses are '''perissodactyl''' '''unguligrade''' animals. Unguligrade means that horses bear their weight on a horny covering ([[Hoof - Horse Anatomy|hoof]]) that surrounds their distal phalanx, perissodactyl means that they have only one weightbearing digit. They are virtually identical in their structure in the hindlimb and forelimb. The main differences are that in the forelimb they have metacarpals and the metacarpophalangeal joint, the hindlimb equivalents are the metatarsals and the metatarsophalangeal joint.  

Only the third metacarpal ('''cannon''') bone remains complete whilst the second and fourth metacarpals are greatly reduced and are known as the '''splint bones'''; metacarpal II is the medial splint and metacarpal IV the lateral splint. Metacarpal I and V are completely absent in the horse.  The splint bones are approximately a third shorter than the metacarpal III. Proximally, the metacarpals articulate with carpal bones. Metacarpal II and III articulate with the second carpal bone and metacarpal IV with the fourth carpal bone.  

Only the third metacarpal ('''cannon''') bone remains complete whilst the second and fourth metacarpals are greatly reduced and are known as the '''splint bones'''; metacarpal II is the medial splint and metacarpal IV the lateral splint. Metacarpal I and V are completely absent in the horse.  The splint bones are approximately a third shorter than the metacarpal III. Proximally, the metacarpals articulate with carpal bones. Metacarpal II and III articulate with the second carpal bone and metacarpal IV with the fourth carpal bone.  

Metacarpal III is robust and well developed, as it has to bear the entire weight transfered through the limb. The distal end of the bone has an articular surface comprised of two condylar areas seperated by a  '''saggital ridge''', which engages with a groove in the proximal phalanx. This ensures only sagittal movement of the fetlock. There is also a '''transverse ridge''' leading to two radii of curvature. The proximal aspect of metacarpal III has articulating facets on its palmar side, where the splint bones articulate. It has a '''metacarpal tuberosity''' on the dorsomedial surface of the proximal end.  

Metacarpal III is robust and well developed, as it has to bear the entire weight transferred through the limb. The distal end of the bone has an articular surface comprised of two condylar areas separated by a  '''saggital ridge''', which engages with a groove in the proximal phalanx. This ensures only sagittal movement of the fetlock. There is also a '''transverse ridge''' leading to two radii of curvature. The proximal aspect of metacarpal III has articulating facets on its palmar side, where the splint bones articulate. It has a '''metacarpal tuberosity''' on the dorsomedial surface of the proximal end.  

The splint bones are held to metacarpal III by strong ligaments which are usually ossified and can lead to lameness if there is excessive bone production. They bones curve away distally from the main shaft and end in rounded nodules, which are important palpable landmarks ('''buttons of the splint'''), approximately a 1/3 to 3/4 of the way down metacarpal III.

The splint bones are held to metacarpal III by strong ligaments which are usually ossified and can lead to lameness if there is excessive bone production. The bones curve away distally from the main shaft and end in rounded nodules, which are important palpable landmarks ('''buttons of the splint'''), approximately a 1/3 to 3/4 of the way down metacarpal III.

===[[Phalanges - Horse Anatomy|Phalanges]]===

===[[Phalanges - Horse Anatomy|Phalanges]]===

 

==Pelvic Limb==

==Pelvic Limb==

|dragster = [[Equine Skeletal Anatomy Dragster resource|Equine Skeleton]]<br>[[:Category:Equine Pelvic Limb Dragster|Equine Hindlimb Resources]]

|dragster = [[Equine Skeletal Anatomy Dragster resource|Equine Skeleton]]<br>[[:Category:Equine Pelvic Limb Dragster|Equine Hindlimb Resources]]

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[[Category:To Do - AP Review]]

[[Category:To Do - AP Review]]