OCR Text |
Show 8 MR. E. J. SIDEBOTHAM ON THE [Jan. 20, mass arising from whole length of sternum and ensiforrn appendix. Fibres converge to a tendon-the posterior ones underlying the anterior ones-which is ultimately united with tendons of chondro-humeral and pectoralis quartus and is inserted into outer lip of bicipital groove of humerus. Its anterior fibres are continuous for a short distance with clavicular portion of deltoid. 0. Underlies preceding portion. It arises in close connection with it from middle of sternum opposite third, fourth, and fifth ribs. Its fibres converge to a flat narrow tendon, which is inserted into outer lip of bicipital groove on a level with upper portion of preceding tendon. Rectus sternalis.-Arises by three tendinous slips from junction of fourth, fifth, and sixth ribs with sternum. It is inserted into anterior surface of first rib at about its middle. Pectoralis quartus.-Arises from fascia lying between scapula and pectoralis major. It is inserted into outer lip of bicipital groove of humerus with chondro-humeral. Chondro-humeral.-A thin band arising in middle line from aponeurosis covering external oblique. Inserted with pectoralis quartus. Supraspinatus.-Arises from supraspinous fossa, inserted into anterior part of neck of humerus, and shoulder capsule. Infraspinatus.-Arises from infraspinous fossa. Inserted just below preceding. Teres minor.-Arises from ventral half of posterior border of scapule between infraspinatus and scapular head of triceps. Inserted just below infraspinatus. Teres major.-A thick fleshy muscle, arising from posterior superior angle of scapula. Inserted by a flattened tendon into inner lip of bicipital groove. Deltoid.-Clavicular and scapular positions quite distinct, excepting just at their insertions. Clavicular portion arises from anterior border of outer half of clavicle and from a small portion of acromion. Inserted into anterior surface of humerus at its upper third, being connected both at its origin and insertion with pectoralis major. Scapular portion arises from posterior surface of spine of scapula and upper portion of infraspinous fossa. Inserted just above clavicular portion. Coraco-brachialis (brevis).-Arises from coracoid, and is inserted into inner part of neck of humerus. Subscapulars.-Arises from subscapular fossa. Inserted into inner part of humerus, near to neck. Levator scapulce.-Arises by a rounded tendon from anterior arch of atlas just internal to acromio-trachelien, and by a few fibres behind this. Its fibres, diverging, are inserted into ventral third of spine of scapula and acromion. Biceps.-Arises by a flat undivided tendon from coracoid and upper margin of glenoid. It consists of two bellies, which are distinct, but closely applied, the coraco-radial one beino- superficial If the tendon is forcibly torn, the coraco-radial head is'seen to arisp |