B. Flexor Division

The three flexors of the carpus are like those of the horse.

The superficial digital flexor is somewhat blended at its origin with the middle flexor of the carpus. It divides into two bellies, superficial and deep, terminating on tendons at the distal part of the forearm. The superficial tendon passes over the posterior annular ligament (Ligamentum carpi transversum), perforates the metacarpal fascia, and joins the deep tendon about the middle of the metacarpus. The deep belly is connected with the deep flexor by a strong fibrous band. Its tendon passes under the annular ligament in a groove on the deep flexor, from which it receives fibers. The conjoined tendon soon bifurcates, each branch receiving a reinforcing band from the suspensory ligament, and forming near the fetlock a ring for the corresponding branch of the deep flexor tendon. Passing under two digital annular ligaments, they are inserted into the volar surfaces of the second phalanges by three slips.

The deep digital flexor has the same heads as in the horse, the humeral head, as before mentioned, being connected with the deep portion of the superficial flexor. The tendon divides near the distal end of the metacarpus into two branches which are inserted into the volar surfaces of the third phalanges.

The synovial sheaths at the carpus present the following special features: One is found in connection with the tendon of the superficial part of the superficial flexor of the digits. There is a common sheath for the tendons of the common extensor and the inner extensor.

Bursæ may occur under the tendons of the proper extensors of the digits at the fetlock; they are constant only in old animals (Schmidtchen). The branches of the tendon of the common extensor are provided with synovial sheaths from their origin to the middle of the second phalanx. There are two digital synovial sheaths for the flexor tendons; they may communicate at their upper part, and extend from the distal third of the metacarpus nearly to the distal sesamoids. Bursæ occur between the latter and the branches of the deep flexor tendon.