Popliteus muscle the ankle. The gastrocnemius muscle acts on both joints. It originates from the lateral surface of the lateral condyle of femur by a rounded tendon, the fibers pass downward and medially and give insertion to the posterior surface of tibia, above the soleal line. The muscle arises within the capsule of knee joint and its tendon separates the lateral meniscus from the lateral ligament of the joint. Nerve supply is via the tibial nerve from spinal roots L5 and S1. There is sometimes an additional head from the sesamoid bone in the lateral (outer) head of the gastrocnemius muscle. Rarely
Bone mineral of the hydroxyapatite. Bone mineral is dynamic in living animals; it is continually being resorbed and built anew in the bone remodeling process. In fact, the bones function as a bank or storehouse in which calcium can be continually withdrawn for use or deposited for storage, as dictated by homeostasis, which maintains the concentration of calcium ions in the blood serum within a particular range despite the variability of muscle tissue metabolism. Parathormone and calcitonin are the principal hormones with which the neuroendocrine system controls this ongoing process. The parathyroid and thyroid glands in the neck produce those hormones; thus,