Changes

The shoulder joint links the humerus and the scapula at the '''glenoid cavity''', which is much smaller than the head of the humerus.  While structually it is a [[Joints - Anatomy & Physiology#Types of Joints|'''ball and socket''']] joint, it functions as a [[Joints - Anatomy & Physiology#Types of Joints|'''hinge joint''']] due to extensive muscling around the articulation.  The joint capsule is enlarged and extends under the tendon of the biceps, acting as a synovial sheath to protect the tendon.

The shoulder joint links the humerus and the scapula at the '''glenoid cavity''', which is much smaller than the head of the humerus.  While structually it is a [[Joints - Anatomy & Physiology#Types of Joints|'''ball and socket''']] joint, it functions as a [[Joints - Anatomy & Physiology#Types of Joints|'''hinge joint''']] due to extensive muscling around the articulation.  The joint capsule is enlarged and extends under the tendon of the biceps, acting as a synovial sheath to protect the tendon.

===Elbow Joint===

===Elbow Joint===

*The radius articulates proximally with the distal humerus, caudally with the ulna, and distally with the carpus

*The radius articulates proximally with the distal humerus, caudally with the ulna, and distally with the carpus

*Medially on the distal articular process, a '''styloid process''' projects, which is mirrored laterally by the ulna

*Medially on the distal articular process, a '''styloid process''' projects, which is mirrored laterally by the ulna

===Ulna===

===Ulna===

The Ulna's greatest contribution to functional anatomy is in the formation of the '''Olecranon''', or the point of the elbow, which gives rise to the attachment of the '''triceps'''.  The olecranon articulates with the humerus via its anconeal process.  Distally (where unfused), the '''lateral styloid process''' articulates with the '''ulnar carpal bone'''.

The Ulna's greatest contribution to functional anatomy is in the formation of the '''Olecranon''', or the point of the elbow, which gives rise to the attachment of the '''triceps'''.  The olecranon articulates with the humerus via its anconeal process.  Distally (where unfused), the '''lateral styloid process''' articulates with the '''ulnar carpal bone'''.

===Carpal bones===

===Carpal bones===

*Distally, bones are numbered 1-5, though 5 is always fused with 4

*Distally, bones are numbered 1-5, though 5 is always fused with 4

*A small [[Bones and Cartilage - Anatomy & Physiology#Types of Bone|'''sesamoid''']] bone embedded in the medial tissues of the joint can sometimes be mistaken as a chip fracture

*A small [[Bones and Cartilage - Anatomy & Physiology#Types of Bone|'''sesamoid''']] bone embedded in the medial tissues of the joint can sometimes be mistaken as a chip fracture

===Metacarpal bones===

===Metacarpal bones===

The joint is a synovial joint, comprised of a common outer fibrous capsule and three inner synovial pouches, one for each joint.  Numerous ligaments add to the stability of the joint and ensure movement is largely limited to the [[Planes and Axes - Anatomy & Physiology|sagittal plane]], although no collateral ligaments exist in the dog between the radius and the proximal metacarpals.  This allows a very small amount of rotation.

The joint is a synovial joint, comprised of a common outer fibrous capsule and three inner synovial pouches, one for each joint.  Numerous ligaments add to the stability of the joint and ensure movement is largely limited to the [[Planes and Axes - Anatomy & Physiology|sagittal plane]], although no collateral ligaments exist in the dog between the radius and the proximal metacarpals.  This allows a very small amount of rotation.

===Metacarpal Joint===

===Metacarpal Joint===

*Action: retracting the limb, may also raise limb

*Action: retracting the limb, may also raise limb

*Innervation: brachial plexus, although in some species, dorsal spinal nerves can innervate

*Innervation: brachial plexus, although in some species, dorsal spinal nerves can innervate

===Deep Musculature Forelimb===

===Deep Musculature Forelimb===

===Muscles of the Elbow===

===Muscles of the Elbow===

===Muscles of Supination and Pronation ===

===Muscles of Supination and Pronation ===

==Species Specifics==

==Species Specifics==