LECTURE XIII. 



THE FOOT. 



The foot, technically includes all structures at and below the 

 knee in front, and the hock behind. This lecture only deals with 

 that portion of the foot below the ankle. 



Bones. — First phalanx ; two sesamoid bones ; second pha- 

 lanx ; navicular bone ; and third phalanx. For first and second 

 phalanges, sesamoids and navicular, see Lecture III. 



The third phalanx is an irregular 

 bone of loose spongy texture. The 

 body is shaped somewhat like the 

 hoof and shows at the top in front 

 a prominence called the pyramidal 

 process, and on each side a projec- 

 tion called the wing, under which 

 may be seen a groove through 

 which groove an artery passes on 

 its way to form part of an arch 

 within the substance of the bone. 

 From this arch is given off the 

 branches which distribute nourish- 

 ment to the vascular parts. Above 

 the wings, inside the hoof, are cav- 

 ities into which the lateral carti- 

 lages fit. They are of firm cartilage 

 and may be felt above the crown of 

 the hoof on each side. They are 

 attached below to the wings of the 

 third phalanx and plantar cushion. 

 To the front and sides of the third 

 plialanx arc attached the sensitive 

 laminae. The inferior surface is concaved to receive the sensitive 

 sole, or velvety tissue. 



FIG. 28. BONES OF THE 



HORSE'S FOOT. 



1, Metacarpal: 2, 2, sesa- 

 moids; 3, first phalanx: 4, sec- 

 ond phalanx: 5, na\icnlar hone; 

 6, third plialanx (os pedis); 7, 

 basilar process; 8, 8, wings; 9, 

 pyramidal process. 



