Changes

==Common structures of the Proximal Forelimb and Shoulder==

 

==Common Structures of the Proximal Forelimb and Shoulder==

===Scapula===

===Scapula===

===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 Humerus is the long bone of the arm, 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 head of the humerus comprises '''greater''' and '''lesser tubercles''', separated by an '''intertubercular groove''' through which runs the tendon of the '''biceps brachii'''. The shaft of the humerus takes on a characteristically twisted shape via a groove carrying the '''brachialis''' and '''radial nerve'''. Laterally, the '''deltoid tuberosity''' is palpable through the skin and connects to the head of the humerus via a ridge and merges distally with the '''crest of the humerus'''. Distally, the humerus culminates in a '''condyle''' which articulates to form the elbow.  

The head of the humerus comprises '''greater''' and '''lesser tubercles''', separated by an '''intertubercular groove''' through which runs the tendon of the '''biceps brachii'''. The shaft of the humerus takes on a characteristically twisted shape via a groove carrying the '''brachialis''' and '''radial nerve'''. Laterally, the '''deltoid tuberosity''' is palpable through the skin and connects to the head of the humerus via a ridge and merges distally with the '''crest of the humerus'''. Distally, the humerus culminates in a '''condyle''' which articulates to form the elbow.  

:In dogs and cats, it articulates with the ulna medially via a trochlea and the radius laterally via a '''capitulum'''

:In dogs and cats, it articulates with the ulna medially via a trochlea and the radius laterally via a '''capitulum'''

:Caudally, all species show an '''olecranon fossa''' which articulates with the '''olecranon''' of the ulna

:Caudally, all species show an '''olecranon fossa''' which articulates with the '''olecranon''' of the ulna

Medial and lateral epicondyles provide attachment for flexors and extensors of the carpus and digits.

Medial and lateral epicondyles provide attachment for flexors and extensors of the carpus and digits.

===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''' muscle.  The olecranon articulates with the humerus via its anconeal process. The olecranon develops as an apophysis, i.e.. from a separate site of ossification. 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''' muscle.  The olecranon articulates with the humerus via its anconeal process. The olecranon develops as an apophysis, i.e.. from a separate site of ossification. The trochlear notch on the cranial aspect of the ulna articulates with the large trochlea of the humerus which forms the main elbow joint capable of flexion and extension. Just distal to the trochlear notch, a large medial '''coronoid process''' and a smaller lateral coronoid process can be seen. Distally (where unfused), the '''lateral styloid process''' articulates with the '''ulnar carpal bone'''.

===Carpal bones===

===Carpal bones===

===Metacarpal Joint===

===Metacarpal Joint===

The metacarpal joint is defined by the presence of palmar [[Bones - Anatomy & Physiology#Types of Bone|'''sesamoids''']], which allow the flexor tendons to pass over the sharp change in angle presented by the joint. They are paired on each digit, with the exception of the first digit where it exists.

The metacarpal joint is defined by the presence of palmar [[Bones - Anatomy & Physiology#Types of Bone|'''sesamoids''']], which allow the flexor tendons to pass over the sharp change in angle presented by the joint. They are paired on each digit, with the exception of the first digit where only one exists. A single '''dorsal sesamoid bone''' can also be seen in dogs in digit 2 - 5 inclusive over the same joint between the metacarpal bone and the proximal phalanx. This is not found in ungulates or in the the first digit. However another sesamoid bone exists in the tendon of the abductor pollicis longus muscle of the first digit.

 

 

==Muscles of the Forelimb==

==Muscles of the Forelimb==

'''''Pectoral mm.''''':  

'''''Pectoral mm.''''':  

:Innervated by: brachial plexus

:Innervated by: brachial plexus

:Two superficial parts, cranial and caudal

:Two superficial parts, cranial and caudal

==Species Specifics==

==Species Specifics==

===[[Canine Forelimb - Anatomy & Physiology|Canine Forelimb]]===

===[[Canine Forelimb - Anatomy & Physiology|Canine Forelimb]]===

===[[Bovine Forelimb - Anatomy & Physiology|Bovine Forelimb]]===

===[[Bovine Forelimb - Anatomy & Physiology|Bovine Forelimb]]===

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

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

[[Category:A&P Done]]

[[Category:A&P Done]]