MORPHOLOGY OF THE MUSCULUS ARTICULARIS GENUS IN DOG WITH DESCRIPTION OF ECTOPIC MUSCLE-SPINDLES

The gross morphology of the musculus articularis genus and the locatio n of muscle spindles at its point of insertion were studied in 18 adul t dogs. The m. articularis genus was usually small and bipartite. From its originate on the cranial surface of the distal femur, it passed d istally to terminate at the femoropatellar-joint capsule surface and e xtend into the synovial membrane. Although the m. articularis genus wa s usually composed of two parts, only a medial part was present in som e dogs and was entirely absent in one specimen. Innervation to the m. articularis genus was provided by a branch of the femoral nerve. Muscl e spindles were abundant in the termination of the muscle. Frequently, the spindles were not in contact with muscle fibres (dissociated). Mu scle spindles were located in close proximity to the surface of the sy novial membrane. Morphological adaptations of the m. articularis genus support its potential function as a monitor of joint movement rather than an extensor of the stifle joint.