INTEODUGTOEY 31 



A smaller head is a capitellum or capitulum. Example: capitel- 

 lum humeri. 



Ramus (a branch) is a term applied to a division or branch of a 

 bone. Example : ramus of the mandible, ramus mandibulce. 



Lingule or lingula (a tongue), cornu (a horn), and ha'mulus (a 

 hook) are terms employed, in a few cases, for small parts of bones. 

 Examples : lingnle of the sphenoid, linytila sphenoidalis, cornua of the 

 sacrum, hamulns of the pterygoid. 



Base and apex are terms sometimes used to denote the broad and 

 the pointed end of a bone, respectively. Example : base and apex of 

 the patella, basis patellce, apex patellce. 



Base may be applied in the ordinary sense to the lower part of a 

 structure. Example: base of the skull, basis era/in. 



EXTERIOR OF BONES. 



The exterior of a bone, or of a part of a bone, presents certain 

 features : 



Surfaces (fades], which may be smooth or irregular; they may 

 afford attachment to muscles or membranes, or may be applied to 

 surfaces of other bones to form joints. Examples : orbital surface of 

 the maxillary, fades orbitalis max illaris ; proximal surface of the 

 radius, fades proximalis radii. 



Parts of surfaces are known as areas or spaces. Examples : area 

 of origin of the tibialis anticus muscle, popliteal space. Intervals 

 between bones are sometimes termed spaces. Example : intercostal 

 spaces, spatia intercostalia. A well-defined space on a bone, either for 

 the attachment of muscles or for articulation with another bone, is 

 sometimes called a facet. 



The term border (crista) is used to denote the ridge or convexity 

 produced by the meeting of two surfaces. Example : anterior border 

 of the humerus. 



The term border (mar go, limbus) is also used in osteology in the 

 ordinary sense, meaning the margin of a thin structure. Example : 

 frontal border of the parietal, mar go frontali*. 



An arch is the curved border of an opening. Example : supra- 

 orbital or superciliary arch, arcus supraorbitalis or arcus superciliaris. 

 Or the term may refer to an actual bony structure arching over a canal. 

 Example : zygomatic arch, arcus zygomaticus. 



