JXTEODUCTOEY 33 



Tuberosity and tubercle are interchangeable and used by different 

 authors for the same structure. 



The tuberosities of the femur are called trochanters (Greek tr<>- 

 chein, to roll), and the tuberosity at the lower end of both the tibia and 

 the fibula is known as a malleolus (a little hammer). 



Promontory in several instances denotes the most prominent part 

 of a surface. Example : promontory of the sacrum, promontorium 

 sacrum. 



Protuberance is occasionally used in place of the term tubercle. 

 Example : external occipital protuberance, protuberantia ocrip/fa/ix 

 exterior. 



An eminence is an obscurely defined elevation or a point of max- 

 imum convexity of a surface. Example: parietal eminence, eminent/a 

 pari<i<tlis. 



A long tapering process is called a spine or spinous process (pro- 

 cessus spinosus) . Examples : post-nasal spine, spina nasalis posterior ; 

 spinous process of a vertebra, processus spinoms vertebrce. 



Crest is sometimes applied to the border of a bone. Example : 

 crest of the ilium, crista Uiaca. 



Rostrum (br<ik} is used, but rarely, for a kind of crest. Example : 

 sphenoidal rostrum, rostrum sphenoidalis. 



A prominent elevation extending along a surface is called a ridge 

 (crista}. Example: bicipital ridges of the humerus, crisfce tuber- 

 culorum. 



A slight elevation along a surface is known as a line. Example : 

 ///tea aspera of the femur. 



(2) Depressions in the surface of bones may be articular de- 

 pressions, to receive articular elevations of various kinds, or may be 

 for the attachments of muscles, or to lodge more delicate structures. 



A deep depression is termed a cavity (xinus) ; when for articula- 

 tion, an articular cavity. Example : glenoid cavity of the scapula, 

 cavitas glenoidea scapuke. 



A broad depressed area on d surface is known as a fossa (ditch}. 

 Example : supraspinous fossa of the scapula, fossa supraspinata. The 

 depressed area may involve several contiguous bones. Example : 

 temporal fossa, fossa temporalis. 



A smaller, more clearly defined depression has been termed a pit, 



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