VEINS OF THE UPPER EXTREMITY. 



151 



Inferior petrosal sinus* — Extends from the cavernous sinus on 

 either side, along the inferior margin of the petrous portion of the 

 temporal bone, arid opens into the lateral sinus near its exit from 

 the cranium. 



Anterior occipital sinus.^ — It passes transversely across the 

 basilar process of the occipital bone, between the two inferior petro- 

 sal sinuses. 



Posterior occipital sinus.^ — This is in the inferior edge of the 

 falx cerebelli, descending from the torcular Herophili ; when it 

 reaches the foramen magnum, it bifurcates and empties into the 

 lateral sinus upon either side. This communication is not repre- 

 sented in the diagram. 



The venous blood from the channels in the diploic structure 

 empties into the sinuses at the base of the cranium. 



Emissaries of Santorini, are small veins passing through minute 

 foramina of the bones of the cranium and forming a communication 

 between the vessels of the scalp and the sinuses of the brain. 



VEINS OF THE UPPER EXTREMITY. 



The veins of the upper extremity are superficial and deep, 

 superficial are readily seen beneath the skin; the deep veins 

 the usual arrangement of the ve?icB comites. The superficial 

 are the following: 



Cephalic.^ — This originates upon the thumb 

 by a branch called cephalicapollicis^ and also 

 upon the back of the hand, and ascending 

 upon the radial side* of the fore-arm, is 

 joined at the elbow by the median cephalic. 

 It pursues its course along the outer side of 

 the arm, and entering a fissure between the 

 pectoralis major and deltoid uwisoXe, it enters 

 into the subclavian vein under the clavicle. 

 It sometimes communicates with the external 

 jugular.2 (Fig. 133.) 



Basilic,'^ commences with the ve?ia salva- 

 tella of the little finger, and receiving large 

 branches upon the ulnar side of the fore-arm, 

 it is joined at the elbow by the median basilic. 

 It then ascends the arm along the inner edge 

 of the biceps muscle, and about its middle is 

 joined by the vena comites to form the axil- 

 lary vein. 



Median.^ — This collects the blood from 

 the anterior face of the fore-arm, and near 

 the elbow communicates^ with the deep veins. 

 It afterwards divides into the median basilic^^ 

 and median cephalic.^^ The latter is the 



The 

 have 

 veins 



