INFLAMMATION OF THE JUGULAR VEIN. 571 



wholly due to coagulation of the blood contained in the inflamed 

 portion of the vein ; for he found, when a portion of a vein was 

 insulated by securing it between two ligatures, emptied of its 

 blood, and inflammation excited by an irritant injection, that a 

 plastic solid substance was formed, which filled up the whole 

 calibre of the vessel. In some instances the plug is formed of 

 concentric layers of straw-coloured lymph, with a dark san- 

 guineous clot in its centre. At first the clot is but loosely 

 attached to the interior of the vessel, but subsequently it be- 

 comes more strongly adherent, the surrounding areolar tissue 

 infiltrated with serum, and that in contact with the vein ad- 

 herent to it by a fibrinous exudate. In this manner the vein 

 and surrounding textures are firmly united. 



Traumatic inflammation of the jugular vein is always circum- 

 scribed — sometimes " suppurative" sometimes ''fibrinous" The 

 thrombus or coagulum extends in an upward direction (from the 

 wound) considerably beyond the primary seat of the inflamma- 

 tion, and terminates in a conical point. The inflammation may 

 terminate by this clot becoming organized, and the vein con- 

 verted into an impervious cord, without the advent of the sup- 

 purative process ; but in the majority of cases one or two cir- 

 cumscribed swellings appear along the course of the coagulum, 

 in which fluctuation and the other characters of abscesses may 

 be detected. The pus in these abscesses is confined by a 

 coao-ulum, above and below, which forms a barrier to its admis- 

 sion into the general circulation. 



Whilst these changes are going on in the inflamed vein, the 

 lips of the wound are separated, everted, are redder than natural, 

 and discharge a sanious material, mingled with blood ; the sur- 

 rounding parts also are in a state of tumefaction and tension, 

 whilst the vein in its course towards the head conveys the 

 sensation to the fingers of a hard cord of considerable thickness. 



It seems peculiar that the formation of the thrombus or clot 

 should extend towards the head and from the heart in inflam- 

 mation of the jugulars, and towards the heart when other veins, 

 such as the brachials or saphence, are accidentally inflamed. We 

 are not to suppose that the inflammation does not extend below 

 as well as above the puncture in phlebitis of the jugular; in- 

 deed, a thickening of the coats of the vessel can be distinctly 

 felt through the skin, but the obliterating clot is not found 



