40 



ANATOMY, AND PHYSIOLOGY OF 



body, neck, sides, and branches ; external 

 and internal surfaces, and corresponding 

 borders. 



Q. What do you understand by these 

 terms ? — A. Body signifies the anterior 

 part reaching posterior to the tusks ; neck 

 signifies the contracted part, immediately 

 posterior to the body; sides are the parts 

 comprehended between the neck and the 

 branches ; the branches are the parts poste- 

 rior to the neck, which terminate in the con- 

 dyles. As regards surfaces.) the external is 

 convex, rounded, rough, and porous, and 

 affords attachment for muscle and gum. 

 The internal surface is concave, rough, and 

 porous, and answers for the attachment of 

 muscles and gum, and as a channel for the 

 tongue, and attachment for the fioenum 

 linguas. 



Q. What do you understand by borders ? 

 — A. Each superior border exhibits six 

 alveolar cavities for the molar teeth ; the 

 septum are composed of osseous laminae. 

 The inferior border is thin and irregular. 

 The posterior border is broad and roughened 

 for the insertion of muscles. 



GENERAL INQUIRIES. 



It is now presumed that we understand 

 the location and names of the different bones 

 composing the cranium and face; and, be- 

 fore we proceed further, it may be profitable 

 to make some general inquiries regarding 

 the bony structure. 



Q. Is not the number of bones greater 

 during colthood than at mature life ? — A. 

 Yes, many of the bones separable at that 

 period become united in the adult. 



Q. How are bones divided ? — A. They 

 are divided into long or cylindrical, broad 

 or flat, and thick. 



Q. What do you understand by epiphy- 

 sisis of bones? — A. The region where car- 

 tilage is interposed between bones that 

 finally become ossified. 



Q. What is the structure of bones? — 

 A. They consist of a cellular, reticular, and 

 vascular parenchyma, and of osseous mat- 

 ter deposited in it: their base, therefore, 

 is the same as that of the soft parts. 



Q. Are bones vascular ? — A. Yes. 



Q. How can you demonstrate their vas- 

 cularity ? — A. By numerous small fora- 

 minae and by the tinge they receive from the 

 coloring matter of the food. 



Q. Name the investing membrane of 

 bones ? — A. Periosteum. 



Q. What is its organization ? — A. Fi- 

 brous. 



Q. Of w^hat use is this periosteum? — 

 A. It limits the growth of bones, is the 

 medium of circulation and nutrition, and 

 affords attachment for ligaments and mus- 

 cles, and favors the free articulation of the 

 latter. 



Q. What does its internal surface se- 

 crete ? — A. An oleaginous fluid, depos- 

 ited in the cellular structure and cavity of 

 bones. 



Q. What are foramina? — A. Holes 

 perforating the substance of bones. 



Q. What are sinuses ? — A. Occurring 

 in bones, they are large cavities with small 

 openings. 



Q. What are sinuosities ? — A. Superfi- 

 cial but broad irregular depressions. 



Q. What are furrows ? — A. Long, nar- 

 row, and superficial canals. 



Q. What are notches ? — A. Cavities in 

 the margin of bones. 



Q. What are fossas ? — A. Deep and 

 large cavities on the surface of bones. 



Q. What are glenoid cavities? — A. 

 Cavities for articulation. 



Q. What are tubercles ? — A. Small em- 

 inences. 



Q. What are tuberosities ? — A. Rough 

 elevations. 



Q. What are spines ? — A. Long pro- 

 jections upon a bone. 



Q. What are heads? — A. The round 

 tops of bones. 



Q. What are necks ? — The narrow por- 

 tion of bones beneath their heads. 



Q. What are processes ? — A. Short pro- 

 jecting portions of bones. 



THE TRUNK (REMARKS ON THE SAMe). 



We shall now consider the peculiarities 

 of the trunk; which comprehends the verte- 



