Part 12

The ligamentum annulare radii originates on the olecranon, surrounds the head of the radius, and is attached to the tuberculum internum of the ulna (Fig. 15, No. 3).

The ligamentum cubiti teres extends from the head of the radius to the upper end of the ulna (Fig. 15, No. 4).

FIG. 14.—Muscles and ligaments of the arm and forearm of a hen.

A. External view. 1, Expansor secundarium. 2, Tensor patagii longus. 3, Tensor patagii brevis. 5, Brachialis anticus. 6, Pronator longus. 7, Supinator brevis. 8, Extensor indicis brevis. 10, Scapulo-humeralis.

B. Internal view. 9, Ligamentum laterale cubiti internum. ]

The ligamentum transversum spreads out between the head of the ulna and the radius, thus uniting the two bones, and limiting supination (Fig. 15, No. 1).

=Ligaments of the Carpal Joint.=—The carpal joint is made up of the ulna, radius, the two carpal bones and the metacarpus.

There are two strong ligamenta obliqua carpi ulnaris which extend from the processus styloideus of the ulna to the tuberculum posterius carpi ulnaris of the os carpi ulnaris.

The ligamentum posticum ulnare carpi ulnaris extends from the processus styloideus of the ulna to the os carpi ulnaris.

FIG. 15.—Ligaments of the arm and forearm of a hen.

A. The scapulo-coraco-humeral articulation. 1, Proximal end of the humerus. 2, Articular head of humerus. 3, The coracoid. 4, Proximal end of the clavicle. 5, Tendon of pectoralis tertius. 6, Tendon of pectoralis secundus. 7, Opening or foramen triossium through which the tendon of the elevator of the wing passes. (Pectoralis secundus.) 8, Broken end of scapula.

B. 1, Ligamentum transversum. 2, Ligamentum laterale cubiti externum. 3, Ligamentum annulare radii. 4, Ligamentum cubiti teres. 5, A portion of the ligamentum capsulare cubiti. 6, Distal extremity of humerus. 7, Ulna. 8, Radius.

C. Muscles of the outside surface of the arm. 1, Tensor patagii longus. 2, Extensor digitorum communis. 3, Tensor patagii brevis. 4, Anconeus. 5, Flexor carpi ulnaris. 6, Biceps. 7, Triceps. 8. Deltoid. 9, Brachialis anticus. 10, Flexor metacarpi radialis. 11, Extensor ossis metacarpi pollicis. 12, Extensor metacarpi radialis longior. 13, Extensor indicis longus. ]

The ligamentum ulnare carpi radialis is a short ribbon-like ligament which passes over the above-mentioned ligaments and is attached to the inner surface of the os carpus radialis.

The ligamentum ulnare carpi radialis internum is a strong ligament which originates on the inner part of the elbow. It extends to the upper rim of the base of the main digit.

The ligamentum radiale carpi radialis externum originates on the outside of the head of the middle digit and inserts to the superior tuberculum carpi radialis of the radius.

The ligamentum carpi radialis internum, a short ligament, extends from the inside of the head of the main digit to the inner rim of the carpi radialis.

The ligamentum carpi interosseum is located between the carpal bones.

The ligamentum ulnare metacarpi internum is spread out between the processus styloideus of the ulna and the tuberositas muscularis on the upper side of the middle finger base at a point where the second and the third metacarpi separate.

The ligamentum ulnare metacarpi externum extends from the tubercle of the distal extremity of the ulna, on the dorsal side, to the tubercle on the base of the metacarpus.

Ligamentum radiale metacarpi extends from the head of the inner digit to a point near the tuberculum muscularis of the radius.

The ligamentum transversum ossis carpi radialis et metacarpi is located between the inferior tuberculum ossis carpi radialis and the first metacarpal bone.

There is another ligament between the tuberculum superiorus carpi radialis and the first metacarpal bone.

The ligamentum ossis carpi radialis internum et metacarpi extends from the inner surface of the carpus radialis to the tuberositas muscularis of the radius.

The ligamentum ossis carpi ulnaris externum et metacarpi extends from the ulnar carpal bone to the tuberculum of the metacarpal bone.

The ligamentum ossis carpi ulnaris internum et metacarpi extends from the processus uncinatus of the ulnar carpal bone to the tuberositas muscularis of the metacarpal bone.

=Ligaments of the Finger.=—The ligamentum pollicare connects the thumb with the first metacarpal bone.

The ligamentum anterius ossis metacarpi et primæ phalangis digiti secundi extends from the tuberculum articulare metacarpi, of the proximal end of the metacarpus, to the tuberculum articulare of the first phalanx of the second or large finger. Similarly attached, are also an internal and a posterior ligament, or ligamentum internum and ligamentum posterius.