

SURFACE ANATOMY OF THE BACK 1303 



'he subclavian artery is indicated on the surface by a curved line, convex upward, 

 from the sternoclavicular articulation to the middle of the clavicle. The highest 

 point of the convexity is from 1 to 3 cm. above the clavicle. 



Veins. The surface marking for the internal jugular vein is slightly lateral 

 and parallel to that for the common carotid artery. The position of the external 

 jugular vein is marked out by a line from the angle of the mandible to the middle 

 of the clavicle. A point on this line about 4 cm. above the clavicle indicates the 

 spot where the vein pierces the deep fascia. The line of the anterior jugular vein 

 begins close to the symphysis menti, runs downward parallel with and a little 

 to one side of the middle line and, at a variable distance above the jugular notch, 

 turns lateralward to the external jugular. 



Nerves. The facial nerve at its exit from the stylomastoid foramen is situated 

 about 2.5 cm. from the surface, opposite the middle of the anterior border of the 

 mastoid process; a horizontal line from this point to the ramus of the mandible 

 overlies the stem of the nerve. To mark the site of the accessory nerve a line is 

 drawn from the angle of the mandible to a point on the anterior border of Sterno- 

 cleidomastoideus about 3 to 4 cm. below the apex of the mastoid process, or to the 

 midpoint of the posterior border of the muscle; the line is continued across the 



posterior triangle to Trapezius. 

 The cutaneous branches of the cervical plexus as they emerge from the posterior 

 border of Sternocleidomastoideus may be indicated as follows: the lesser occipital 

 begins immediately above the midpoint of the border and runs along the border to 

 the scalp; the great auricular and cervical cutaneous both start from the middle 

 of the border, the former running upward toward the lobule of the auricula, the 

 latter crossing Sternocleidomastoideus at right angles to its long axis; the supra- 

 clavicular nerves emerge from immediately below the middle of the posterior border 

 and run down over the clavicle. The phrenic nerve begins at the level of the middle 

 of the thyroid cartilage and runs behind the clavicle about midway between the 

 anterior and posterior borders of Sternocleidomastoideus. 



The upper border of the brachial plexus is indicated by a line from the side of 

 the cricoid cartilage to the middle of the clavicle. 



Submaxillary Gland. On either side of the neck the superficial portion of the 

 submaxillary gland, as it lies partly under cover of the mandible, can be palpated. 



SURFACE ANATOMY OF THE BACK. 



Bones. The only subcutaneous parts of the vertebral column are the apices 

 of the spinous processes. These are distinguishable at the bottom of a furrow 

 which runs down the middle line of the back from the external occipital protuber- 

 ance to the middle of the sacrum. In the cervical region the furrow is broad and 

 ends below in a conspicuous projection caused by the spinous processes of the 

 seventh cervical and first thoracic vertebra. Above this, the spinous process of the 

 sixth cervical vertebra sometimes forms a projection; the other cervical spinous 

 processes are sunken, but that of the axis can be felt. In the thoracic region the 

 furrow is shallow and during stooping disappears, and then the spinous processes 

 become more or less visible; the markings produced by them are small and close 

 together. In the lumbar region the furrow is deep and the situations of the spinous 

 processes are frequently indicated by little pits or depressions, especially when the 

 muscles in the loins are well-developed. In the sacral region the furrow is shallower, 

 presenting a flattened area which ends below at the most prominent part of the 

 dorsal surface of the sacrum, i. e., the spinous process of the third sacral vertebra. 

 At the bottom of the sacral furrow the irregular dorsal surface of the bone may be 

 felt, and below this, in the deep groove running to the anus, the coccyx. 



The only other portions of the vertebral column which can be felt from the 

 surface are the transverse processes of the first, sixth, and seventh cervical vertebrae. 



