HEAD AND ANTERIOR CERVICAL STRUCTURES. 



27 



Divide the sternal origin of the sterno-mastoid. Remove the tissues covering the stemo- clavicular joint 

 and expose the ligaments. The clavicular attachment of the sterno-mastoid should be preserved until 

 the dissection of the subclavian and carotid arteries is completed, and their relations studied. 



Sterno-clavicular articulation, 227-8-9-30. (233-4-5-6) 

 Class. Diarthrosis. Subdi v ision . Arthrodia. 

 Capsular ligament : 



Posterior sterno-clavicular ligament. 

 Anterior sterno-clavicular ligament. 



Below. Superior portion. 

 Interclavicular ligament. 

 Rhomboid or costo-clavicular ligament. 



Remove the anterior ligament and expose the interarticular fibro-cartilage within the 

 joint. 



Interarticular fibro-cartilage. 



Synovial membrane. 

 Arterial supply. 

 Nerve-supply. 

 Movements. 

 Behind the sterno-clavicular joint, 1127. (1103-4) 



Carefully divide the remaining ligaments of the sterno-clavicular articulation, and draw the sternal end 

 of the clavicle slightly forward; with ihe saw divide the clavicle by an oblique incision extending from 

 the outer margin of the sterno-cleido-mastoid to the lower portion of the sternal extremity of the bone. 

 Raise the fragment of clavicle with the attached sterno-cleido mastoid, and, carefully separating the 

 muscle from the structures underneath, turn it upward to its insertion. In raising the muscle, note the 

 vessels and nerves entering its deep surface. The sterno-mastoid must not be detached at its insertion 

 until the dissection of the subclavian and carotid vessels is completed. When these vessels are exposed, 

 replace the sterno mastoid in position while studying their relations. As the jugular and subclavian 

 veins lie in a plane superficial to the arteries, they may be first exposed, and then pushed aside while 

 the more important vessels, the arterial trunks, are being displayed. Beginning above, trace the ter- 

 minal or exposed portion of the tributaries to the internal jugular, and follow the internal jugular from 

 the posterior belly of the digastric to its termination ; the upper portion of the vessel will be exposed at 

 a later period of the dissection. 



Facial vein, common facial vein, 650. (637-8) 

 Submental vein, 651. (638) 

 Inferior or descending palatine vein, 651. 

 Submaxillary or glandular veins, 651. 

 Communicating branch, or anterior division of the temporo-maxillary vein, 651. 



Chief variations in the facial vein. 



Lingual vein, 665-6. (652) 

 Superior thyroid vein, 666. (652) 

 Middle thyroid vein, 666. (652) 

 Internal jugular vein, 665. (6512) 

 Tributaries. 



Expose the scaleni muscles and the subclavian vessels. Care must be exercised not to injure the small 

 branches of the cervical or the brachial plexus, or the branches of the subclavian artery. A portion of 

 the pleura of the lung will also be exposed, but must not be injured. The termination of the thoracic 

 duct will be found at the junction of the subclavian and internal jugular veins. 



Scalenus anticus, 484; Fig. 316. (4767) 



Origin. Insertion. Structure. Nerve-supply. 

 Scalenus medius, 484; Fig. 316. 



Origin. Insertion. Structure. Nerve-supply. 

 Scalenus posticus, 484-5. (477) 



Origin. Insertion. Structure. Nerve-supply. 

 Variations of the scaleni. 



Subclavian vein, 682-3. (668-9) 

 Tributaries. 



Chief variations in the subclavian vein. 

 Cervical portion of the thoracic duct, 699. (683-4) 



Action. Relations. 

 Action. Relations. 

 Action. Relations. 



