AND PHYSIOLOGY. 



35 



nutrient membrane of the bones. Besides 

 this function, the periosteum serves as a 

 point of attachment for the ligaments and 

 tendons, in as much as they could not find 

 firm attachments on the bone itself. 



Remark. — Diseases of Periosteum. — In 

 the diseases known as Felon and Fever Sore, 

 the Periosteum is the seat of the inflamma- 

 tion, although, if it be not soon checked, the 

 bone itself becomes implicated. 



90. Processes of Bones. — The bones of 

 animals are not constructed after any regu- 

 lar geometrical form or curve, but are mod- 

 eled upon the plan which may secure the 



n , „ .,. a . Periosteum of a hume- 



greatest firmness and iacility ot motion. m s partly taken off. 

 Accordingly we find their surfaces quite 

 uneven, presenting in many places prominent projections, 

 which serve as a firm point of attachment for muscles and 

 ligaments. These are called Processes, and are generally 

 found near the extremities of bones, and are largest where 

 the greatest strength of muscle and ligament is required, as 

 shown in the bones of the lower extremities. 



91. Nutritious Foramina. — Upon nearly all the bones of 

 the body may be found small tubular openings which, after 

 extending for a short distance into the bone, ramify and give 

 off the minute capillary vessels which circulate through the 

 larger Haversian canals. They are called nutritious fora- 

 mina, or openings, since they convey nutriment to a large 

 portion of the bone. 



92. Four Classes of Bones. — Bones are divided according 

 to their shape into four classes : long, flat, short, and irregu- 



What is the seat of Felon and Fever Sore ? 90. What is the general outline of bones? 

 What are Processes? 91. What are the nutritious foramina, and with what vessels do 

 they communicate ? Their use ? 92. Give the four classes of bones, and give examples 

 of the long ones. 



