Anatomy of the Cat

by Jacob Reighard; H. S. Jennings

Relations.—The muscle is covered throughout by the two heads of the gastrocnemius ([Fig. 90], m; [Fig. 91], k), except at the proximal end ([Fig. 90], l), where it is in contact with the integument. Inner surface in relation with the popliteus ([Fig. 92], k), the soleus ([Fig. 90], o), the flexor longus digitorum ([Fig. 91], n), and flexor longus hallucis ([Fig. 91], m).

M. soleus ([Fig. 90], o).—A flat fusiform muscle lying beneath the plantaris.

Origin by muscle-fibres from the lateral surface of the head of the fibula, and by tendon-fibres from the proximal two-fifths of its ventral border.

Insertion.—The muscle ends in a slender tendon which joins the lateral border of the gastrocnemius tendon to form the tendon of Achilles ([Fig. 90], t), which forms the sheath of the plantaris tendon.

Relations.—Outer surface with the gastrocnemius ([Fig. 90], m) and plantaris ([Fig. 90], l). Inner surface with the peroneus longus ([Fig. 90], q), peroneus tertius ([Fig. 90], r), and flexor hallucis ([Fig. 91], m).

Action.—Assists the gastrocnemius to extend the foot.

M. triceps suræ.—The gastrocnemius and the soleus are sometimes considered as forming a single muscle, with three heads, under the name triceps suræ.

M. popliteus ([Fig. 92], k).—A triangular muscle passing from the femur obliquely toward the medial side over the ventral surface of the proximal end of the tibia.

Origin by a strong tendon from the popliteal groove on the surface of the lateral epicondyle of the femur. In the tendon is a sesamoid bone, the popliteal bone ([Fig. 61], 5, [page 89]), which glides over the ventral part of the lateral articular facet on the proximal end of the tibia. As the muscle passes over the joint it is closely attached to the joint capsule. From the popliteal bone, which with the tendon lies within the capsule of the knee-joint, the muscle-fibres diverge to their

Insertion into the proximal end of the ventral surface of the tibial shaft on the medial side of the medial oblique ridge. The area of insertion extends slightly onto the medial surface of the bone.