Extrafusal muscle fiber Extrafusal muscle fiber Extrafusal muscle fibers are the skeletal standard muscle fibers that are innervated by alpha motor neurons and generate tension by contracting, thereby allowing for skeletal movement. They make up the large mass of skeletal muscle tissue and are attached to bone by fibrous tissue extensions (tendons). Each alpha motor neuron and the extrafusal muscle fibers innervated by it make up a motor unit. The connection between the alpha motor neuron and the extrafusal muscle fiber is a neuromuscular junction, where the neuron's signal, the action potential, is transduced to the muscle fiber by the neurotransmitter acetylcholine. Extrafusal
Fourth metatarsal bone on the lateral side a single facet, for articulation with the fifth metatarsal. The head or anterior extremity articulates with the fourth proximal phalanx, the first bone in the fourth toe. The third and fourth dorsal interossei muscles attaches to the fourth metatarsal bone. The third dorsal interossei from the medial side of the bone and the fourth dorsal interossei from the lateral side. The function of the muscle is to spread the toes. The second Plantar interossei muscle originates from the medial side of the base and shaft of the fourth metatarsal. The function of the muscle is to