180 PRINCIPLES OF veterinary SCIENCE 



The different structures comprising the foot are: (1) organs 

 which give the foot elasticity; (2) sensitive or nutritive organs of the 

 foot; (3) the protective organ of the foot. 



The plantar cushion is the chief elastic organ. It is a buffer 

 of nbro-elastic tissue, situated between the horny frog below, 

 the deep flexor tendon above, and the lateral cartilages on each 

 side. It assists the horny frog in lessening jar and protecting 

 the foot. 



The lateral cartilages comprise the other two elastic organs. 

 They were described with the bones of the foot. 



The pododerm is the collective term used for the sensitive 

 organs of the foot. It covers the foot in a manner similar to 

 that in which the skin envelops other parts of the body, but is 

 relatively thicker and more resistant. Instead of producing 

 the epidermis and hair, it gives rise to and furnishes nutrition 

 for the hoof. When exposed it is found to be the red, sensitive 

 tissue, commonly called the "quick." For convenience the 

 pododerm is divided into the perioplic band, the coronary band, 

 the sensitive laminee, the sensitive sole, and the sensitive frog. 

 Each of these parts nourishes a corresponding part of the hoof. 



The perioplic band is a very narrow ring of flesh running around 

 the hoof-head just above the coronary band. From the fine 

 villi on the surface of this band the periople, or hoof varnish, is 

 secreted. This substance is thin, hard, and brittle when dry, 

 its function being to hold moisture and keep the hoof soft and 

 elastic. 



The coronary band is a bolster-like structure, about % inch 

 wide, which extends entirely around the foot from the bulb of 

 one heel to that of the other. It lies in a groove at the upper 

 border of the hoof. From it the horny wall is nourished. 



The sensitive laminae consist of a large number of fleshy 

 leaves, longer at the toe than at the heel, that correspond with 

 laminse of the wall, which they nourish. 



The sensitive sole covers all the lower surface of the foot ex- 

 cept the plantar cushion. It presents thousands of villi which 

 nourish the horny sole. 



The sensitive frog covers the lower surface of the plantar 

 cushion and nourishes the horny frog. 



The hoof is the protective organ of the foot. It is the box, or 

 case of horn, enclosing the sensitive structures. Numerous 



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