62 



ANATOMY AND PHYSIOLOGY. 



the crown of the hoof. It is studded with Httle papillae. From 

 these grow downward the tubular fibers which make up the hard 

 layer of the wall. 



The sensitive laminae are 500 to 600 layers of vascular tis- 

 sue into which fit and from which grow the horny laminae of the 

 wall. An inflammation here is called laminitis or founder. 



FIG. 29. THE HOOF. 



The Wall. A, Toe; B, quarter ; 0, heel. 



Ground Surface, a-a. Toe; a-b, (luarter; b-d, heel; c, bar; f, f, f, sole; 

 g, white line; h, frog; I, cleft of the frog. 



The velvety tissue covers the upper surface of the hard sole. 

 Like the coronary band and sensitive laminae, it is sensitive and 

 richly supplied with l)lood. The under surface is thickly stud- 

 ded with papillae, similar to those of the coronary band, and 

 from these in a similar way grow the shorter tubular fibers which 

 make up the hard sole and frog. The student can easily under- 

 stand why injury to the coronary band, which results in a heal- 

 ing by scar tissue, leaves a split which lengthens downward in 

 the hoof; why founder is so painful; and why deep injuries to 

 the sole are so apt to be serious. 



The plantar cushion is a wedge-shaped mass of elastic tis- 

 sue located between the lateral cartilages on each side, below 

 the sole of the third phalanx and above the horny sole of the 

 hoof. It assists the horny frog in lessening jar in travel and 

 protects the insertion of the deep flexor tendon. 



"The back tendons" is a term used by horsemen to include 

 the tendons of the superficial and deep flexor nmscles of the 

 foot and the suspensory ligament. 



