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=Forelimb=
=Forelimb=
==Structures of the Proximal Forelimb and Shoulder==
===[[Forelimb - Anatomy & Physiology#Scapula|Scapula]]===
The Scapula forms the basis of the shoulder region, providing points of attachment of extrinsic and intrinsic muscles. It is held in place by a synsarcosis of muscles and does not form a conventional articulation with the trunk. The spine culminates in the '''acromion'''. The scapular cartilage is comprised of only a very narrow rim.
===[[Forelimb - Anatomy & Physiology#Clavicle|Clavicle]]===
In the cat, a remnant of bone may remain embedded in the fibrous intersection in the brachiocephalicus, which may prove misleading in radiographic images.
===[[Forelimb - Anatomy & Physiology#Humerus|Humerus]]===
The Humerus is the long bone of the forearm, articulating with the scapula to form the shoulder and the radius and ulna to form the elbow. In situ, it lies obliquely along the ventral thorax and is more horizontal in larger species. The greater tubercle is not separated into two parts like in other species. In dogs and cats, it articulates with the ulna medially via a '''trochlea''' and the radius laterally via a '''capitulum'''.
===[[Forelimb - Anatomy & Physiology#Radius|Radius]]===
A radial tuberosity provides a site of attachment for brachialis and biceps brachii mm. This roughened area is very variable in size in dogs and can be non-existent.
===[[Forelimb - Anatomy & Physiology#Ulna|Ulna]]===
The ulna shaft tapers distally, lying oblique to the radius, i.e. the proximal end lies medial and the distal end lateral to the radius. There is a distinct gap between it and the radius, which is filled by the pronator quadratus muscle. The distal styloid process is blunt and articulates with the ulnar carpal bone, accessory carpal bone and ulnar notch of the radius.
==Joints of the Proximal Forelimb==
===[[Forelimb - Anatomy & Physiology#Shoulder Joint|Shoulder Joint]]===
The joint capsule barely extends past the areas of articulation, except where it continues distally into the intertubercular groove of the humerus. This provides cushioning and synovial support for the bicipital tendon. The bicipital tendon and the joint capsule pouch are held in place by the '''transverse humeral retinaculum''', which lies between the greater and lesser tubercles of the humerus.
===[[Forelimb - Anatomy & Physiology#Elbow Joint|Elbow Joint]]===
The radius articulates with the capitulum and lateral trochlear surface of the humeral condyle. Whilst the medial part articulates with the trochlear notch of the ulna. To allow the radius to rotate slightly the radial head has a marginal band of cartilage making the articular circumference. It faces the radial notch of the ulna between the medial and lateral coronoid processes. The joint capsule runs from just proximal to the articular surface of the condyle of the humerus to the periphery of the olecranon fossa; it pouches between the ulna and radius, and under the tendinous attachments of some muscles.
'''Collateral ligaments''' are paired and lie medially and laterally. They both attach proximally to the epicondyle and distally to the tuberosities of the radius and ulna.
'''Annular ligament''' of the radius attaches to the sides of the coronoid process of the ulna. This runs deep to the collateral ligaments and forms a ring for the radial head to turn in during pronation and supination.
The radius and ulna are joined mid-shaft by the '''interosseous ligament''', the remainder is filled by the interosseous membrane.
==Structures of the Distal Forelimb==
===[[Forelimb - Anatomy & Physiology#Carpal bones|Carpal Bones]]===
Carpal bones comprise two rows:
Proximally - the radial and intermediate bones are fused to form the '''radial''' carpal bone. The accessory carpal bone articulates with both the ulnar carpal bone and the distal ulna.
Distally - bones I-IV are present.
===[[Forelimb - Anatomy & Physiology#Metacarpal bones|Metacarpal Bones]]===
These are covered in detail in the [[Canine Phalanges - Anatomy & Physiology|canine phalanges]] section.
==Joints of the Distal Forelimb==
===[[Forelimb - Anatomy & Physiology#Carpal Joint|Carpal Joint]]===
The '''synovial membranes''' form three compartments corresponding to each joint. The proximal is the largest whilst the middle carpal and carpometacarpal sacs communicate and extend into the intermetacarpal articulations. The fibrous joint capsule is common to all three joints and attaches to the individual bones and various intercarpal ligaments. The '''extensor retinaculum''' is fibrous collagenous tissue on the dorsal aspect that allows passage of the extensor tendons. On the palmar aspect lies the '''palmar carpal fibrocartilage''', that provides attachment for some metacarpal bones. Paired '''collateral ligaments''' bridge the sides of the three main articulations.
The '''flexor retinaculum''' is the carpal fascia on the palmar aspect, and lies between the accessory carpal bone and the medial aspect of the carpus. This with the joint capsule and medial surface of the accessory carpal bone, makes up the '''carpal canal'''. It houses just the deep digital flexor tendon in the dog. The intermetacarpal joints, are tight joints between the proximal ends of the metacarpals. The joint capsules are continuous with that of the carpal joint. They are held together by the '''interosseous metacarpal ligaments'''.
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=Hindlimb=
=Hindlimb=