Lymph Vessels of the Muscles of the Forelimb

The lymph vessels of the muscles of the forelimb mostly drain to the axillary lymph node, and, to a smaller extent, into the superficial cervical, cranial mediastinal, and intercostal lymph nodes. Lymph vessels of all the muscles of the shoulder and brachium (M. deltoideus, M. supraspinatus, M. infraspinatus, M. teres minor, M. subscapularis, M. teres major, M. coracobrachialis, M. biceps brachii, M. brachialis, M. triceps with its three heads, M. anconeus and M. tensor fasciae antebrachii) drain to the axillary lymph node. The lymph vessels of some of the muscles (namely the M. deltoideus, supraspinatus, infraspinatus, teres minor and subscapularis) additionally drain into the superficial cervical lymph nodes. The lymph vessels from a single muscle (M. subscapularis) drain into either the cranial mediastinal lymph nodes or the intercostal lymph node, in addition to the axillary lymph node and superficial cervical lymph nodes.

The lymph vessels of the muscles of the antebrachium (M. brachioradialis, M. extensor carpi ulnaris, M. supinator, M. abductor pollicis longus, M. pronator quadratus, M. pronator teres, M. flexor carpi radialis, M. flexor carpi ulnaris, M. flexor digitalis sublimis and M. flexor digitalis profundus) drain without exception to the axillary lymph node, but this behaviour is limited to the actual muscles: only a very small number of the lymph vessels of the tendons and tendon sheaths drain to the axillary lymph node and, instead, most drain into the superficial cervical lymph nodes. The lymph vessels of the tendons of the flexor carpi ulnaris and flexor carpi radialis drain only to the axillary lymph node, and the lymph vessels of the tendons of the extensor carpi radialis, extensor digitalis communis, extensor digitalis lateralis, extensor carpi ulnaris, M. abductor pollicis longus, flexor digitalis sublimis, and flexor digitalis profundus drain to both to the axillary lymph node and the superficial cervical lymph nodes. The lymph vessels from the antebrachial and carpal parts of the flexor digitalis sublimis and flexor digitalis profundus drain to the axillary lymph node, while the lymph vessels from the metatarsal and toe parts of these tendons drain to the superficial cervical lymph nodes, a finding that is consistent with the behaviour I observed in the cow. Notably, the lymph vessels of the Mm. interossei at the metacarpus as well as the adductors, abductors and flexors of the 1^st and 5^th toe drain not only to the superficial cervical lymph nodes, but also to the axillary lymph node.