_Relation of Artery, Vein and Nerve._—The common carotid artery lies in relation to the internal jugular vein and the pneumogastric nerve. The artery lies to the inside next to the muscles surrounding the trachea (windpipe). The internal jugular artery lies to the outside of the artery. Just back of the common carotid artery and the internal jugular vein and between the two lies the pneumogastric (vagus) nerve. These all as a rule lie in the same common sheath of deep fascia. =How to Locate and Inject the Axillary Artery.=—The axillary in recent years has come to be a much used artery. It not quite as large as the common carotid, but as a rule large enough to admit the large size arterial tube. It has become a favorite with many because it is quite easy to locate and to raise, and because of its proximity to the axillary vein, a vein which is large enough to admit a drainage tube for the withdrawal of blood. Again the axillary artery is in a secluded place, being as it is in the axillary space (arm pit). The artery does not lie very deep, and is not covered by any muscles as you operate, there being practically nothing to hinder the progress of the operation. [Illustration: FIG. 47—The axillary and its branches. (Gray)] Then after the operation is completed and the arm placed back in normal position, the casual observer is not liable to see the incision, even though the body be only partially dressed. _Linear Guide._—A line drawn through the center of the axillary space (arm pit), at the anterior border of the hair line. _The Axillary Space._—When the arm is maintained in a horizontal plane, the axilla has the shape of a three-sided pyramid, the apex of which lies above, below the clavicle, and the base of which corresponds to the lower wall, covered only by skin and fascia. The axilla is filled with blood vessels, lymph vessels, lymph glands, nerves, and masses of fat. _To Raise the Artery._—Make an incision on the linear guide. After the skin is passed through there is a large quantity of fascia, lymph glands, and lymph vessels, which must be carefully dissected through, and at the same time the axillary vein will be discovered. This vein, for the present, should not be loosened from the surrounding tissues. Dissect down to the upper side of the vein, and the common sheath of fascia surrounding the artery and nerves will be seen. By carefully tearing this the length of the incision, the brachial plexus of nerves now is exposed. Now by gently pushing the nerves apart with the handle of the scalpel, the artery will be seen. With a hook loosen the artery from the surrounding tissues and raise to the surface. If it is desired to draw blood, now proceed to raise the vein to the surface. Open the vein and insert a drainage tube, which should be long enough to reach through the entire length of the axillary and subclavian veins, because they have valves along their entire course nearly to the bifurcation of the innominate.