All of the following muscles have parallel oriented fibers except:
(A) Saorius (B) Rectus abdominis (C) Sternohyoid (D) Tibialis anterior
(D) Ans: D. Tibialis anterior(Ref Gray's. 41/e p112, 40/e p104-105).Individual fibers of muscle are arranged either parallel or oblique to long axis of the muscle.Saorius, rectus abdominis & sternohyoid - Parallel oriented fibers.Tibialis anterior muscle - Multipennate muscle with oblique fibers. Muscles with Parallel FasciculiMuscles with Oblique FasciculiMuscles in which fasciculi are parallel to the line of pull & have greater degree of movement.Types:Quadrilateral: ThyrohyoidStrap-like: Sternohyoid & saorius Strap-like with tendinous intersections:Rectus AbdominisFusiform: Biceps brachii, digastricMuscles in which fasciculi are oblique to the line ofpull, muscle may be triangular, or pennate (feather? like) in the constructionArrangement makes muscle more powerful.Reduces range of movement.Types:Triangular: Temporalis, adductor longusdegUnipennate: Flexor pollicis longus, extensor digitorum longusdegBipennate: Rectus femoris, flexor hallucis longusdegMultipennate: Tibialis anterior, submscapularis, deltoid (acromial fibers).