1358 



SUEFACE AND SUEGICAL ANATOMY. 



Bony Landmarks of the Cranium. At the root of the nose is the fron to- 

 nasal suture (nasion) ; a little above it is the glabella, a slight prominence which 

 connects the superciliary arches. About 1 in. below the posterior pole of the 



Epicranial aponeurosis 



Lax connective tissue 



Pericranium 



Outer table of cranial wall 



Diploe 



Anastomosis between arteries of 



scalp and those of the dura mater 



Inner table of cranial wall 



Dura ma 

 Parasinoidal sinus 1 



Cerebral vein opening into. 

 superior sagittal sinus 



Integument 



Artery in superficial fascia 



Vein in superficial fascia 



Vein of the diploe connecting 

 the veins of the scalp with those 

 of the dura mater 



Vein in dura mater 



Arachnoid mater 



Pia mater 



| Arachnoideal granulation 

 [Cortex cerebri 



Superior sagittal sinus 

 Vein in pia-arachnoid 



ub-arachnoid space 



FIG. 1066. DIAGRAMMATIC REPRESENTATION OF A FRONTAL SECTION THROUGH THE SCALP, CRANIUM, 

 MENINGES, AND tlORTEX^ CEREBRI (modified from Cunningham). 



cranium, and 2 in. above the spine of the epistropheus, is the external occipital 

 protuberance (inion). In the child the protuberance is not developed ; its position 

 may be denned by taking a point at the junction of the upper and middle thirds 

 of a line extending from the posterior pole of the skull to the spine of the epi- 

 stropheus. About a third of the distance from the nasion to the inion is the 

 bregma or junction of the coronal and sagittal sutures ; with the head in the 

 natural erect posture the bregma corresponds to the middle of a line carried across 

 the vertex between the pre-auricular points of the zygomatic arches. 



At birth the position of the bregma is occupied by the fonticulus frontalis, a rhom- 

 boidal membranous area which generally becomes ossified at about the eighteenth 

 month. The size and date of closure of the fontanelle, as well as its tension and pulsa- 

 tion, are all points to be carefully noted in the clinical examination of children. 



The lambda, or junction of the sagittal and lambdoidal sutures, situated 2 J in. 

 above the inion, can generally be felt through the scalp ; a line drawn from it to 

 the posterior border of the root of the mastoid process corresponds to the lambdoidal 

 suture. In the adult the parieto-occipital fissure of the brain lies opposite, or a few 

 millimetres in front of, the lambda ; in the child, however, the fissure may be as 

 much as 1 in. in front of it. 



Crossing the supra-orbital margin close to its medial angle, a finger's-breadth 

 from the medial line, are the supra-trochlear nerve and the frontal branch of the 

 ophthalmic artery; the latter nourishes the flap in the operation of rhiuoplasty. 

 At the junction of the medial and intermediate thirds of the supra-orbital margin, 

 1 in. from the medial line, is the supra-orbital notch or foramen, the guide to the 

 supra-orbital vessels and nerves. A little above the level of the lateral can thus 

 of the eyelid is the fronto - zygomatic suture, immediately above which is the 

 zygomatic process of the frontal bone. At the posterior end of the suture the 

 zygomatico-temporal branch of the orbital nerve pierces the temporal fascia to reach 

 the scalp. Half an inch above the suture is the lower margin of the cerebral hemi- 

 sphere ; while half an inch below the suture is a small tubercle on the posterior border 



