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==Introduction==

==Introduction==

==Bones==

==Bones==

====Metacarpals and Metatarsals====

====Metacarpals and Metatarsals====

The arrangement of the metatarsals are similar to those of the metacarpals in that they are rod shaped bones, numbered from I to V. The 1st is the most medial and is very small, the 3rd and 4th are the longest. The proximal base of each articulates with it's corresponding carpal bone and the adjacent metacarpal. The distal end is it's head, which is transversely cylindrical and articulates with the proximal phalanx. Metacarpals II - V possess a sagittal ridge on their palmar aspects.  

The arrangement of the metatarsals are similar to those of the metacarpals in that they are rod shaped bones, numbered from I to V. The 1st is the most medial and is very small, the 3rd and 4th are the longest. The proximal base of each articulates with it's corresponding carpal bone and the adjacent metacarpal. The distal end is its head, which is transversely cylindrical and articulates with the proximal phalanx. Metacarpals II - V possess a sagittal ridge on their palmar aspects.  

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====Phalanges====

====Phalanges====

The proximal phalanx of the main digits (II - V) have a concave articular surface and the palmar border has a groove to accomodate the articular surface of the metacarpus when the joint is fixed. The distal head has two convex areas separated by a groove. The middle phalanx is roughly two-thirds the length of the proximal phalanx and its base has a sagittal ridge on the articular surface which articulates with the groove of the proximal phalanx. The head resembles that of the proximal phalanx. The distal phalanx is made up of a cone-shaped ungual process with a distinct collar called the 'ungual crest'. The deep ungual groove distal to the crest provides attachment for the proximal border of the claw and articulates with the middle phalanx via a small sagittal crest. A bony sesamoid bone is found on the dorsal aspect of the metacarpophalangeal joint. The 'dew claw' (metacarpal I) is normally present in the forelimb but often not in the hindlimb. It normally only consists of two phalanges that resemble the proximal and distal ones.

The proximal phalanx of the main digits (II - V) have a concave articular surface and the palmar border has a groove to accomodate the articular surface of the metacarpus when the joint is fixed. The distal head has two convex areas separated by a groove. The middle phalanx is roughly two-thirds the length of the proximal phalanx and its base has a sagittal ridge on the articular surface which articulates with the groove of the proximal phalanx. The head resembles that of the proximal phalanx. The distal phalanx is made up of a cone-shaped ungual process with a distinct collar called the 'ungual crest'. The deep ungual groove distal to the crest provides attachment for the proximal border of the claw and articulates with the middle phalanx via a small sagittal crest. A bony sesamoid bone is found on the dorsal aspect of the metacarpophalangeal joint. The first digit (sometimes called the 'dew claw') of the forelimb is fully formed and functional. In the hindlimb, the equivalent first digit is often not present or contains only nail, skin and connective tissue (sometimes called 'wolf's claw' in this case)<ref>Budras, KD, McCarthy PH, Fricke, W, Richter, R (2007) '''Anatomy of the Dog''', ''Schlütersche Verlagsgesellschaft mbH&Co.''</ref>

==Joints==

==Joints==

====Claw====

====Claw====

The claw is the horny covering of the distal phalanx. The walls of the claw, which are continuous dorsally, embrace the soft flaky horn of the sole when they touch the ground. The proximal part of the claw, called the '''coronary border''' fits between the ungual groove and the ungual crest, where it is continuous with the skin, making the '''claw fold'''. The periosteum of the distal phalanx is continuous with the dermis, which is arranged in '''papillae'''. Papillae cover the dorsal aspect of the phalanx and contain the '''germinative layer''' which is the flat keratinised epidermal cells which are considered responsible for horn formation. The lateral and medial walls are formed by dermal laminae, rather than the papillae. The plantar aspect of the claw is produced by papillae but this horn is very friable. Canine claws grow at rapid rate and so if they aren't worn by active wear they must be trimmed. Care must be taken as the dermis is highly vascular and bleeding will occur if it is cut into.  

The claw is the horny covering of the distal phalanx. The walls of the claw, which are continuous dorsally, embrace the soft flaky horn of the sole when they touch the ground. The proximal part of the claw, called the '''coronary border''' fits between the ungual groove and the ungual crest, where it is continuous with the skin, making the '''claw fold'''. The periosteum of the distal phalanx is continuous with the dermis, which is arranged in '''papillae'''. Papillae cover the dorsal aspect of the phalanx and contain the '''germinative layer''' which is the flat keratinised epidermal cells which are considered responsible for horn formation. The lateral and medial walls are formed by dermal laminae, rather than the papillae. The plantar aspect of the claw is produced by papillae but this horn is very friable. Canine claws grow at rapid rate and so if they aren't worn by active wear they must be trimmed. Care must be taken as the dermis is highly vascular and bleeding will occur if it is cut into.  

[[Category:Musculoskeletal System - Anatomy & Physiology]]

[[Category:Musculoskeletal System - Anatomy & Physiology]]

[[Category:A&P Done]]

[[Category:A&P Done]]