THE SHOULDER AND ARM 1409 



higher specific gravity than the cerebro-spinal fluid, will tend to gravitate there (Barker). 

 The level of the anaesthesia can be varied by raising the pelvis or the shoulders to different 

 levels. 



The following table, from Holden and Windle, with additions, will be found very useful in 

 determining the relation of numerous viscera and other structures to the bodies of the vertebrae. 



VERTEBRAL LEVELS 



Cervical 



First. Level of hard palate. 



Second. Level of free edge of upper teeth. 



Second and third. Superior cervical ganglion of sympathetic. 



Fourth. Hyoid bone. Upper apertm-e of larj^nx. 



Fifth. Thyreoid cartilage and rima glottidis" Between this and the last would be the 

 bifurcation of the common carotid. 



Sixth. Cricoid cartilage. Ending of pharynx and larynx. Consisting of the fused fifth 

 and sixth ganglia, the middle cervical ganglion is usually opposite this vertebra. Here the 

 omo-hyoid crosses the common carotid, and at this spot, the seat of election, the centre of the 

 incision for tying this vessel is placed. At this level the inferior thyreoid passes behind the 

 carotid trunk. 



Seventh. Inferior cervical ganglion. Apex of lung. Arch of thoracic duct over apex of 

 lung, outward and downward to termination. 



Thoracic 



First. Summit of arch of subclavian. (Godlee.) The height of this varies. Usually 

 it is from 1.2 to 2.5 cm. (§ to 1 in.) above the clavicle. It is always in close relation with the 

 cervical pleura. 



Second. Level of episternal notch. This is usually opposite the fibro-cartilage between 

 the second and third. Bifurcation of innominate. (Godlee.) 



Third. Beginning of superior cava, at junction of first right costal cartilage with sternum. 

 Highest part of aortic arch, about 2.5 cm. (1 in.) below notch. 



^ ^Fourth. Bifurcation of trachea. Second piece of aortic arch, extending from upper border 

 ofi'second right costal cartilage, reaches spine. Arch of vena azygos. The superior medias- 

 tinum is bounded behind by the upper four thoracic vertebrae. Louis' angle, junction of manu- 

 brium and gladiolus. Thoracic aorta begins. 



Fifth to ninth. Base of heart. 



Sixth. Pulmonary and aortic valves, opposite third left costal cartilage at its sternal junc- 

 tion, in front. Commencement of aorta and pulmonary artery. End of superior cava, third 

 right chondro-sternal junction in front. 



Seventh. Mitral orifice. 

 [Eighth. Tricuspid orifice. 



Ninth. Lower level of manubrium and sterno-xiphoid line (at lower border). Opening 

 injdiaphragm for inferior vena cava (lower border). 



Tenth. Level of tip of .xiphoid cartilage. Lower limit of lung posteriorl3\ Upper limit 

 of/Uver comes to the surface posteriorly. (Esophagus passes through diaphragm. Cardiac 

 orifice of stomach (sometimes). Upper limit of spleen. 



Eleventh. Lower border of spleen. Suprarenal gland. Cardia (sometimes). 



Twelfth. Lowest part of pleura. Aorta passes through diaphragm (lower border). 

 Cceliac artery (lower border). Upper end of kidney. 



Lumbar 



First. Superior mesenteric arteries. Pancreas. Pelvis of kidney. Renal arteries. 

 Transpyloric line. (Addison.) 



Second. Spinal cord ends at junction of first and second. Duodeno-jejunal flexure. Re- 

 ceptaculum (cisterna) chyli. Lower end of left kidney. 



Third. Umbilicus, opposite disc between third and fourth. Lower end of right kidney. 



Fourth. Bifurcation of aortic arch. Highest part of iliac crest. 



Fifth. Commencement of superior vena cava. 



Sacral 



Third. End of pelvic colon and beginning of first piece of rectum proper. Lower limit 

 of spinal membranes. 



Fifth. Reflexion of recto-vesical pouch of peritoneum 2.5 cm. (1 in.) above base of prostate. 



Coccyx (tip). 2.5 cm. (1 in.) below this commencement of anal canal. Termination of 

 filum terminale. 



THE UPPER EXTREMITY 



THE SHOULDER AND AR:\I 



The surface form and landmarks of the upper extremity will first be considered 

 followed by the various regions of the shoulder, arm, forearm and hand. 



89 



