506 



ANATOMY IN A NUTSHELL 



LESSON CLXIX. 

 Frontal Bone. (Plates GCXXXVII-CCXXXVIII.) 



The frontal bone consists of two main parts, a vertical or frontal por- 

 noN which forms the forehead, and a horizontal or orbito-nasal portion 

 which forms the roofs of the orbits and nasal fossae. 



The external surface of the vertical portion lias the following points for 

 consideration : 



1. Tin. metopic suture (presenl in the young) is situated in the middle 

 of the fn.nial bone. (Plate CCXXXVIII.) 



2. The frontal eminence is just below the center of the bOne externally 

 from the mid-lino. 



PLATE CCLXVL 





?- J^BERT.INT^J^g CAV1TY 



RENAL ARTERY 



! NFUNDIBUIU^ 



Sagittal Section of the Kidney. 



3. The arched superciliary ridge is below the frontal eminence and 

 separated from it by a groove. This ridge, which is produced by the frontal 

 sinus, is more disl bid internally. 



4. The glabella or nasal eminence is between the superciliary ridges and 

 - continuous with them. 



5. Tin si praorbital ^rch is the upper margin of the orbit and separates 

 the vertical and horizontal portions of the frontal bone. 



6. The si praorbital mi >t< ii or foramen is at the junction of the inner and 

 middle thirds <>f this arch. It transmits the supraorbital vessels and nerve 



