Anatomical terms of muscle This may be a bone, a tendon or the subcutaneous dermal connective tissue. Insertions are usually connections of muscle via tendon to bone. The insertion is a bone that tends to be distal, have less mass, and greater motion than the origin during a contraction. Muscles may also be described by the direction that the muscle fibres run in. Hypertrophy is increase in muscle size from an increase in size of individual muscle cells. This usually occurs as a result of exercise. Anatomical terms of muscle Muscles are described using unique anatomical terminology according to their actions and structure. There
Opponens pollicis muscle Opponens pollicis muscle The opponens pollicis is a small, triangular muscle in the hand, which functions to oppose the thumb. It is one of the three thenar muscles, lying deep to the abductor pollicis brevis and lateral to the flexor pollicis brevis. The opponens pollicis originates from the flexor retinaculum of the hand and the tubercle of the trapezium. It passes downward and laterally, and is inserted into the whole length of the metacarpal bone of the thumb on its radial side. Like the other thenar muscles, the opponens pollicis is innervated by the recurrent branch of the median nerve.