Chap. I.] 



THE SCALP. 



Trephining. This operation is frequently per- 

 formed in the temporal region, its object being to 

 reach extravasations of blood from the middle menin- 

 geal artery. This artery crosses the anterior inferior 

 angle of the parietal bone at a point \~ inches behind 

 the external angular process of the frontal bone, and 

 If inches above the zygoma. 



In cutting down to the bone m the temporal 



D E 



Fig. 2. Points for Trephining. 



A, B, Spots ftir trephining in middle Imeningroiil liivniorrhage ; c, ppot for tre- 

 phining in abscess of the temporo-sphonoidal lobe ; K, spot for trephining in 

 abscess of the cerebellum ; u, mastoid foramen. (After Nancrede.) 



region the following structures are met with in order : 

 (1) The skin ; (2) branches of the superficial temporal 

 vessels and nerves ; (3) the fascia continued down 

 from the epicranial aponeurosis ; (4) the temporal 

 fascia ; (5) the temporal muscle ; (6) the deep temporal 

 vessels ; and (7) the pericranium. 



Trephining for meningcal hemorrhage. Unless 

 localising symptoms give other indications, Kronlein 

 advises that the trephine holes in cases of meningeal 



