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==Overview==

==Overview==

Cattle are '''artiodactyl unguligrade''' animals. '''Unguligrade''' means that they bear their weight on a horny covering (hoof) that surrounds their distal phalanges. '''Artiodactyl''' means that they bear weight on an even number of digits. 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 want to talk about the fore or hindlimb.  

Cattle are '''artiodactyl unguligrade''' animals. '''Unguligrade''' means that they bear their weight on a horny covering ([[Hoof - Anatomy & Physiology|hoof]]) that surrounds their distal phalanges. '''Artiodactyl''' means that they bear weight on an even number of digits. 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 want to talk about the fore or hindlimb.  

==Bones==

==Bones==

===Metacarpals and Metatarsals===

===Metacarpals and Metatarsals===

The arrangement of the metatarsals are similar to those of the metacarpals. Metacarpal III and IV fuse in the fetus to form the large metacarpal bone. The site of fusion is marked by vascular grooves on the dorsal and palmar surfaces of the shaft of the bone. Metacarpal V remains only as a small lateral remnant. The distal end has two seperate articular surfaces seperated by the sagittal '''intertrochlear notch'''. The articular surfaces have two condyles separated by a sagittal ridge. The dorsal aspect of the proximal end has a tuberosity for muscular attachment.  

The arrangement of the metatarsals are similar to those of the metacarpals. Metacarpal III and IV fuse in the fetus to form the large metacarpal bone. The site of fusion is marked by vascular grooves on the dorsal and palmar surfaces of the shaft of the bone. Metacarpal V remains only as a small lateral remnant. The distal end has two separate articular surfaces separated by the sagittal '''intertrochlear notch'''. The articular surfaces have two condyles separated by a sagittal ridge. The dorsal aspect of the proximal end has a tuberosity for muscular attachment.  

===Phalanges===

===Phalanges===

The proximal phalanx tends to be triangular with the interdigital surface being flattened. The proximal end is concave with a sagittal groove so it can articulate with the metacarpal bone, the palmar aspect has facets for the sesamoid bones. The distal head has two convex areas seperated by a sagittal concavity. The middle phalanx is three sided and 2/3rds the length of the proximal one. The proximal end is made up of two concavities and a sagittal ridge. The distal end resembles that of the proximal phalanx. The distal phalanx is pointed, the proximal end has two articular surfaces seperated by a ridge. The solar surface is flattened and has a flexor tubercle for the attachment of the deep digital flexor tendon. The axial surface faicng the other digit is also flattened. The abaxial surface is rounded and is the parietal surface of the claw. Just distal to the metacarpophalangeal joint on the palmar aspect of the limb, lie a pair of conical accessory claws. These are covered with horn and often contain dense connective tissue and small nodules of bone.

The proximal phalanx tends to be triangular with the interdigital surface being flattened. The proximal end is concave with a sagittal groove so it can articulate with the metacarpal bone, the palmar aspect has facets for the sesamoid bones. The distal head has two convex areas separated by a sagittal concavity. The middle phalanx is three sided and 2/3rds the length of the proximal one. The proximal end is made up of two concavities and a sagittal ridge. The distal end resembles that of the proximal phalanx. The distal phalanx is pointed, the proximal end has two articular surfaces separated by a ridge. The solar surface is flattened and has a flexor tubercle for the attachment of the deep digital flexor tendon. The axial surface facing the other digit is also flattened. The abaxial surface is rounded and is the parietal surface of the claw. Just distal to the metacarpophalangeal joint on the palmar aspect of the limb, lie a pair of conical accessory claws. These are covered with horn and often contain dense connective tissue and small nodules of bone.

==Joints==

==Joints==

The movement of the fetlock joint allows flexion and extension. The cow has a pair of fetlock joints involving the metacarpal bone, the two proximal phalanges and two pairs of sesamoid bones. These sesamoids articulate with the proximal palmar edge of the proximal phalanges. Cattle have a joint capsule for the articulation of each digit with the palmar parts communicating.  

The movement of the fetlock joint allows flexion and extension. The cow has a pair of fetlock joints involving the metacarpal bone, the two proximal phalanges and two pairs of sesamoid bones. These sesamoids articulate with the proximal palmar edge of the proximal phalanges. Cattle have a joint capsule for the articulation of each digit with the palmar parts communicating.  

'''Collateral ligaments''' - bind the the furrow between the two articulating areas of the metacarpal bone to the proximal phalanx.

'''Collateral ligaments'''  

:- bind the furrow between the two articulating areas of the metacarpal bone to the proximal phalanx.

'''Interdigital intersesamoid ligament''' - unites the axial sesamoids of each digit together.

'''Interdigital intersesamoid ligament'''  

:- unites the axial sesamoids of each digit together.

'''Interdigital phalangosesamoid ligaments''' - a pair of ligaments that cross each other as they connect the sesamoid of one digit to the proximal phalanx of the other.

'''Interdigital phalangosesamoid ligaments'''  

:- a pair of ligaments that cross each other as they connect the sesamoid of one digit to the proximal phalanx of the other.

'''Proximal interdigital ligament''' - connects the proximal halves of the two digits. Not technically part of the fetlock joint, it is absent in sheep.

'''Proximal interdigital ligament'''  

:- connects the proximal halves of the two digits. Not technically part of the fetlock joint, it is absent in sheep.

'''Collateral sesamoid ligaments''' - connect the outer aspect of the sesamoids to the proximal phalanx and there is a distinct branch that attaches to the metacarpal bone.  

'''Collateral sesamoid ligaments'''  

:- connect the outer aspect of the sesamoids to the proximal phalanx and there is a distinct branch that attaches to the metacarpal bone.  

'''Distal sesamoid ligaments''' - a collection of ligaments that are very marked in the horse. They connect the distal surface of the sesamoids to the plamar aspect of the phalanx. These are:

'''Distal sesamoid ligaments'''  

:- a collection of ligaments that are very marked in the horse. They connect the distal surface of the sesamoids to the palmar aspect of the phalanx. These are:

'''Short ligaments''' - connect the axial base of the sesamoids to the lateral/medial aspect on the palmar margin of the proximal phalanx. These are the deepest of the ligaments.

'''Short ligaments'''  

:- connect the axial base of the sesamoids to the lateral/medial aspect on the palmar margin of the proximal phalanx. These are the deepest of the ligaments.

'''Cruciate ligaments''' - paired ligaments from the base of the sesamoids that diagonally cross to attach to the proximal phalanx. It lies superficial to the short ligaments.

'''Cruciate ligaments'''  

:- paired ligaments from the base of the sesamoids that diagonally cross to attach to the proximal phalanx. They lie superficial to the short ligaments.

===Proximal Interphalangeal/Pastern Joint===

===Proximal Interphalangeal/Pastern Joint===

The pastern joint allows flexion and extension. The joint capsule is simple and attaches by the articular margins of the two phalanges.

The pastern joint allows flexion and extension. The joint capsule is simple and attaches by the articular margins of the two phalanges.

'''Collateral ligaments''' - connect the distal end of the proximal phalanx to the proximal end of the middle phalanx. They lie in a vertical direction rather than along the bone axis.

'''Collateral ligaments'''  

:- connect the distal end of the proximal phalanx to the proximal end of the middle phalanx. They lie in a vertical direction rather than along the bone axis.

===Distal Interphalangeal/Coffin Joint===

===Distal Interphalangeal/Coffin Joint===

The coffin joint allows extension and slight flexion. A distal sesamoid is closely associated with the distal phalanx, which has a navicular bursa present like in the horse. The joint capsule attaches to the articular periphery. There is a dorsal recess under the extensor tendons and a palmar one that runs to about half the height of the middle phalanx.  

The coffin joint allows extension and slight flexion. A distal sesamoid is closely associated with the distal phalanx, which has a navicular bursa present like in the horse. The joint capsule attaches to the articular periphery. There is a dorsal recess under the extensor tendons and a palmar one that runs to about half the height of the middle phalanx.  

'''Collateral ligaments''' - connect the distal part of the middle phalanx to the sides of the proximal distal phalanx.  

'''Collateral ligaments'''  

:- connect the distal part of the middle phalanx to the sides of the proximal distal phalanx.  

'''Dorsal ligament''' - yellow elastic tissue connecting the proximal dorsal border of the middle phalanx to the extensor process of the distal phalanx.  

'''Dorsal ligament''' - yellow elastic tissue connecting the proximal dorsal border of the middle phalanx to the extensor process of the distal phalanx.