48 THE AiniY HORSE. 



and an anterior, which runs forward and downward through 

 the phuitar cushion and supplies the sensitive frog. 



The pre plantar ungual artery is giA^en oti' inside the wing 

 of the OS pedis, passes through the prephmtar notch, and runs 

 forward along the preplantar groove on the side of the bone. 

 It helps supply the sensitive laminsc with blood and sends 

 some small branches into the bone to join branches from other 

 arteries. 



The j^lciniar ungual artery is the terminal or last branch of 

 the digital artery (is a continuation of that artery) and enters 

 the OS pedis at the plantar foramen. 



The two plantar ungual arteries run forward within the 

 bone and unite to form the circulus arteriosus. From this 

 circle spring ascending and descending branches. The ascend- 

 ing liranches, called the anterior laminal arteries, leave the 

 bone through t'lie small openings (foramina) and supply the 

 sensitive lamina- in front. The descending branches, called 

 the inferior eo7nmunieating arteries, are about fourteen in 

 number and emerge from the bone by the openings just above 

 its lower edge ; they unite to form a large trunk, running 

 around the toe of the os pedis, called the circumflex artery, 

 and this artery gives off ascending and descending branches. 

 The ascending branches pass into the sensitive lamina^ and 

 the descending branches, called the solar arteries, numbering 

 about fourteen, run backAvard through the sensitive sole to 

 form a second circle, called the inferior circumflex artery. 



The veins of the foot are arranged in networks, each network 

 or plexus named from the parts in which it is located. The 

 solar plexus is found running all through the sensitive sole. 

 The laminal plexus runs through and under the sensitive 

 lamina. The coronary plexus surrounds the os corona and 

 upper part of the os pedis, just under the coronary band. 



The veins of the frog are those found in the plantar cushion 

 and sensitive frog; the interosseous veins form a network 

 within the os pedis. The veins of the foot all unite above to 

 form a large trunk, called the digital vein, which runs along 

 the digital artery and carries the blood back toward the heart. 

 The veins of the foot are valveless below the middle of the 

 pastern, an arrangement which allows the blood to flow in 

 either direction when pressure is applied and thus prevents 

 injury. 



