\\ \TOMY IX A NUTSHELL. 449 



gins of the interspaces, (f) perforating branches which pass through the 

 five or six upper interspaces to the skin and muscles on the chest, and those 

 that pass through the second, third, and fourth spaces go to the mammary 

 gland. 



Of its terminal branches the musculo-phrenic runs behind the cartilages 

 of the false ribs to pierce the Diaphragm at the eighth or ninth rib and ends at 

 the twelfth rib where it gives off anterior intercostals to the lower intercostal 

 spaces pericardiac branches, and diaphragmatic branches. 



Its other terminal branch the superior epigastric descends in the interval 

 between the sternal and costal attachments of the Diaphragm to pierce the 

 sheath of the Rectus muscle running on its posterior surface to anastomose 

 with the deep epigastric in the substance of this muscle. 



LESSON CXL. 



(3) The thyroid axis arises near the the Scalenus Anticus from the first 

 portion of subclavian artery and gives off inferior thyroid, suprascapular, and 

 trans versalis colli arteries. 



The inferior thyroid artery ascends behind the middle cervical ganglion of 

 the sympathetic and the sheath of the common carotid artery to the thyroid 

 gland. It crosses the vertebral artery, Longus colli muscle, and the recurrent 

 laryngeal nerve. It may, however, pass under this nerve. Its branches are, 

 (a) tracheal, which pass to the trachea, (b) oesophageal, which pass to the 

 oesophagus, (c) muscular, which pass to the adjacent muscles, (d) inferior 

 laryngeal, which passes to the back of the larynx with the recurrent laryn- 

 geal nerve, (e) ascending cervical, which passes between the Scalenus an- 

 ticus muscle and the Rectus capitis anticus major on the anterior tubercles of 

 the transverse processes. 



The suprascapular artery crosses the Scalenus anticus muscle behind the 

 clavicle and passes over the transverse ligament of the scapula to the supra- 

 spinous and infraspinous fossa?. This artery goes to the clavicle, scapula, and 

 humerus, as well as to the sterno-clavicular articulation and acromio-clavicu- 

 lar articulation and the shoulder girdle. 



The transversalis colli is on a higher level than the suprascapular artery and 

 crosses the Scaleni muscles and the brachial plexus to the Trapezius muscle. 

 Here it divides two branches, (a) superficial cervical which ascends under 

 the anterior border of the Trapezius to anastomose with the superficial branch 

 of the arteria princeps cervicis, (b) tiiio posterior SCAPULAR branch, which 

 runs under the Levator anguli scapulae to the superior angle of the scapula and 

 then descends under the Rhomboidei muscles to the inferior angle of the scapula. 

 This artery may arise from the third portion of the subclavian. 



(4) The superior intercostal comes from the upper and hack pari of the 

 subclavian artery and descends on the neck of the first two ribs to supply 

 the first two intercostal spaces. In the first intercostal space it gives off a 

 branch which is distributed in like manner to the aortic intercostals. The 

 artery in the second intercostal space generally joins one from the highest 

 aortic intercostal. All intercostal arteries give off branches to the posterior 



