28 SUPERFICIAL ANATOMY OF THE TRUNK. 



bending the column forwards. The fourth lumbar spine is on a level with the 

 highest part of the crest of the ilium : the third lumbar spine is generally somewhat 

 higher than the umbilicus. 



The spine of the scapula is easily felt beneath the skin, and may be traced out- 

 wards (very little upwards when the arm is hanging) to the acromion, which is 

 represented on the surface by a depression in a muscular subject, or when the arm 

 is raised. The lower border of the spine and the outer border of the acromion meet 

 in the prominent acromial angle, which is always to be distinctly recognized on the 

 surface ; from this point measurements of the length of the arm are most 

 conveniently taken. The vertebral border and the inferior angle of the scapula are 

 seen, although covered for the most part by muscles, the former by the trapezius, 

 the latter by the latissimus dorsi. The superior border cannot usually be 

 distinguished, but the axillary border can be felt more or less distinctly through its 

 thick muscular covering. With the arms hanging by the side, the upper angle of 

 the scapula corresponds to the upper border of the second rib, or the interval 

 between the first and second dorsal spines ; the lower angle to the seventh inter- 

 costal space (sometimes the eighth rib) or the interval between the seventh and 

 .eighth dorsal spines ; and the root of the spine of the scapula to the interval 

 between the third and fourth dorsal spines. The vertebral border of the bone is at 

 the same time nearly perpendicular. 



At the inner end of the spine of the scapula, a distinct depression indicates the 

 triangular tendon in which the lower fibres of the trapezius end ; and a slight groove, 

 which is seen at times passing upwards and outwards over the surface of the 

 eminence formed by the erector spinae, in the direction of a line from one of the 

 lowest dorsal spines to the triangular tendon, marks the lower edge of the muscle. 

 Immediately above the spine of the scapula is a convex surface formed by the 

 thickest part of the trapezius covering the supraspinatus muscle ; and above this, the 

 sloping surface leading down from the neck to the shoulder is formed by the upper 

 part of the trapezius, supported by the levator anguli scapula and by fat. 



The lower ribs are to be felt through the latissimus dorsi, outside the edge of the 

 erector spinas ; but it must be borne in mind that the twelfth rib is often very short 

 and does not project beyond the margin of the erector muscle, so that the lowest rib 

 that can then be felt is the eleventh. The ribs should, therefore, always be counted 

 from above downwards, and not from below upwards. 



The lower end of the larynx and pharynx, and the commencement of the 

 trachea and oesophagus are about on a level with the interval between the sixth and 

 seventh cervical spines. From this spot the trachea descends, at first in the middle 

 line, and then inclining slightly to the right divides opposite the fourth dorsal spine 

 into the two bronchi. The latter are thence directed outwards and downwards, the 

 right usually more nearly in the line of the trachea, and the left becoming more 

 transverse in direction, to the hilum of the lung, which they enter about the level 

 of the fifth dorsal spine. In the lung the main prolongation of the bronchus 

 descends, accompanied by corresponding pulmonary vessels, which are placed 

 dorsally to the air-tube, about one and a half or two inches (4 5 cm.) from the 

 median plane, towards the hinder part of the base of the lung. 



Lungs and pleurae. The apex of the lung, corresponding to the neck of the 

 first rib, extends up to the level of the seventh cervical spine. Mesially, the lungs 

 touch the sides of the bodies of the vertebras ; and inferiorly, they reach down to 

 the tenth dorsal spine, the pleura to the eleventh or even lower, as has already been 

 described (p. 20). 



The oesophagus, from its commencement, inclines at first somewhat to the left, 

 but regains the middle line about the fifth dorsal vertebra ; in its lower part it is 

 deflected more considerably to the left, and it terminates at the cardiac orifice of the 



