Changes

Jump to navigation Jump to search

Bovine Lower Limb - Anatomy & Physiology (view source)

Revision as of 12:11, 22 August 2008

9,899 bytes added ,  12:11, 22 August 2008
no edit summary
Line 1: Line 1:  
<big><center>[[Musculoskeletal System - Anatomy & Physiology|'''BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY''']]</center></big>
 
<big><center>[[Musculoskeletal System - Anatomy & Physiology|'''BACK TO MUSCULOSKELETAL ANATOMY AND PHYSIOLOGY''']]</center></big>
 +
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 in the forelimb we 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'''==
 +
 +
===='''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 seperated by a sagittal ridge.
 +
* The dorsal aspect of the proximal end has a tuberosity for muscular attachment.
 +
 +
 +
 +
===='''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 is rounded and is the parietal surface of the claw. 
 +
 +
 +
 +
=='''Joints'''==
 +
 +
 +
===='''Metacarpophalangeal/Fetlock Joint'''====
 +
 +
 +
* Movement - flexion and extension.
 +
* This joint is associated with a pair of sesamoid bones on the palmar surface. Between the sesamoids in a groove lies articular cartilage which articulates with the sagittal ridge of metacarpal III.
 +
* The joint capsule runs between all bones in the joint and  attaching to the articular cartilage of the sesamoids. It has an extensive pouch under the extensor tendon continuing a quarter the length up the cannon bone.
 +
* '''Collateral ligaments''' - bind the the metacarpal bone to the proximal phalanx, with a deep branch attaching to the sesamoid bone.
 +
* '''Palmar/intersesamoidean ligament''' - a mass of fibrocartilage that embedd the sesamoid bones. The palmar aspect of it forms a groove for the deep flexor tendon to run in.
 +
* '''Collateral sesamoid ligaments''' - connect the outer aspect of the sesamoids to the proximal phalanx and there is a distinct branch that attaches to the cannon 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:
 +
** '''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.
 +
** '''Oblique ligament''' - a triangular shaped ligament; the base of which attaches to the sesamoids and their interconnecting ligament and the point attaches to the rough palmar aspect of the proximal phalanx. It is superficial to the cruciates.
 +
** '''Straight ligament''' - proximally attaches like the oblique but attaches as a flat band to the edge of the complementary fibrocartilage of the proximal end of the middle phalanx.
 +
* There exists a '''palmar annular ligament''' which wraps around the sesamoids, flexor tendons and their associated sheaths.
 +
 +
===='''Proximal Interphalangeal/Pastern Joint'''====
 +
 +
 +
* Movement - flexion and extension.
 +
* The palmar border of the middle phalanx has a complementary fibrocartilage that extends the proximal articular surface of the middle phalanx. It is sometimes called the middle scutum as it provides a gliding surface for the deep digital flexor.
 +
* The joint capsule is simple and attaches by thr 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. The fibres of the '''collateral sesamoid ligaments''' of the distal interphalangeal joint run with it, attach to the middle phalanx and then continue on to their distal attachments.
 +
* '''Palmar ligaments''' - connect the palmar aspect of the distal half of the proximal phalanx to the complementary fibrocartilage of the middle phalanx.
 +
* A '''proximal digital annular ligament''' wraps around the superficial surface of the flexor tendons and their sheaths at the level of the proximal phalanx. There is a distal one also exists that is attached to the proximal phalanx, it is superficially associated with the digital cushion and is connected to the ergot by the thin fibrous '''ligament of the ergot'''. 
 +
 +
 +
===='''Distal Interphalangeal/Coffin Joint'''====
 +
 +
 +
* Movement - extension, slight flexion.
 +
* The '''navicular bursa''' lies between the navicular bone and the deep flexor tendon.
 +
* 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. It is dips between the distal phalanx and sesamoid and bulges laterally where it is related to the collateral ligaments.
 +
* '''Collateral ligaments''' - connect the distal part of the middle phalanx to the sides of the proximal distal phalanx.
 +
* '''Distal sesamoid ligaments'''' - connect the distal border of the navicular bone to the flexor surface of the distal phalanx.
 +
* '''Collateral sesamoid ligaments''' - fibroelastic ligaments that attach to the proximal phalanx with the collateral ligaments of the pastern joint and insert to the proximal border of the navicular bone.
 +
* The ungual/lateral cartilages have a series of ligaments going to the medial/lateral surfaces of the three phalanges and distal sesamoid. There is also a fibrous band connecting the inner surfaces of the cartilages by crossing the superficial aspect of the deep digital flexor tendon.
 +
 +
=='''Musculature'''==
 +
 +
'''Interosseous/Suspensory ligament'''
 +
* Function - support of the metacarpophalangeal joints.
 +
* Origin - palmar aspect of the proximal end of the metacarpal bones, distal row of carpal bones and the joint capsule of the carpus.
 +
* Insertion - At the level of distal metacarpal III it splits into two tendons that attach to the sesamoids and continue along the flanks of the proximal phalanx before appearing on the dorsal surface and attaching to the extensor tendon. 
 +
 +
 +
====Forelimb====
 +
 +
'''Superficial digital flexor'''
 +
* Function - flexion of the digits
 +
* Origin - medial epicondyle of the humerus
 +
* Insertion - palmar aspect of the middle phalanx and the distal extremity of the distal phalanx
 +
 +
 +
'''Deep digital flexor'''
 +
* Function - flexion of the digits
 +
* Origin - medial epicondyle of the humerus, proximal radius and ulna
 +
* Insertion - palmar aspect of distal phalange
 +
 +
 +
'''Common digital extensor'''
 +
* Function - extensor of the digits
 +
* Origin - distal extremity of the humerus in and lateral to the coronoid fossa, the lateral tuberosity of the proximal extremity of the radius, the lateral aspect of the shaft of the ulna.
 +
* Insertion - extensor process of the distal phalanx, the dorsal surfaces of the proximal and middle phalanges.
 +
 +
 +
'''Lateral digital extensor'''
 +
* Function - extensor of the digits
 +
* Origin - lateral tuberosity of the radius, the shaft of the ulna
 +
* Insertion - proximal phalanx
 +
 +
 +
====Hindlimb====
 +
 +
 +
'''Long Digital Extensor'''
 +
* Origin - extensor fossa of the lateral femoral condyle.
 +
* Insertion - extensor process of the distal phalanx, the dorsal surfaces of the proximal and middle phalanx.
 +
 +
 +
'''Lateral Digital Extensor'''
 +
* Origin - lateral ligament of the stifle, the fibula, lateral border of tibia and the interosseous ligament.
 +
* Insertion - It joins to the tendon of the long digital extensor about a third of the way down the metatarsus.
 +
 +
 +
'''Superficial Digital Flexor'''
 +
* Origin - Supracondylar tuberosity of the femur.
 +
* Insertion - the calcaneus, eminences on the sides of the proximal part of the middle phalanx, distal extremity of the proximal phalanx behind the collateral ligaments of the pastern.
 +
 +
 +
'''Deep Digital Flexor'''
 +
* Origin - lateral tibial condyle, fibula, interosseous ligament.
 +
* Insertion - the solar surface of the distal phalanx.
 +
 +
=='''Vasculature'''==
 +
*'''[[Arteries of the Forelimb - Anatomy & Physiology|Arteries of the Forelimb]]'''
 +
*'''[[Veins of the Forelimb - Anatomy & Physiology|Veins of the Forelimb]]'''
 +
*'''[[Lymphatics of the Forelimb - Anatomy & Physiology|Lymphatics of the Forelimb]]'''
 +
*'''[[Arteries of the Hindlimb - Anatomy & Physiology|Arteries of the Hindlimb]]'''
 +
*'''[[Veins of the Hindlimb - Anatomy & Physiology|Veins of the Hindlimb]]'''
 +
*'''[[Lymphatics of the Hindlimb - Anatomy & Physiology|Lymphatics of the Hindlimb]]'''
 +
 +
=='''Innervation'''==
 +
[[Hindlimb - Anatomy & Physiology|Innervation of the Hindlimb]]
 +
 +
 +
=='''The Bovine Hoof'''==
Jtulloch
3,320

edits

Retrieved from "https://en.wikivet.net/Special:MobileDiff/30795"

Navigation menu