Study on muscular architecture and distributions of intramuscular nerves and motor endplates of the biceps brachii in rabbit

Objective To reveal the relationship among muscle architecture and distributions of intramuscular nerves and motor endplatcs of Biceps brachii in rabbit. Methods Muscle architecture method; Modified sihler's staining; Acetylcho- linesterase staining. Results Muscle weight 2. 65 ± 0. 16g, muscle length 5. 44 ± 0. 18cm, muscle fibre length 1. 45 ± 0.17cm, Pennate angles 20°, physiologic cross-sectional area(CSA)1 . 64 ± 0. 16cm2 . Intramuscular nerves derived from the branches of musculocuteneous nerve and median nerve. Motor endplates were located on midpoint of muscle fibers, they arranged each other into motor endplate bands, there were varied shape in defferent plane. Conclusions There was a tendon plate in Biceps brachii of rabbit, muscle fibers arranged into ring-pennate shape. Biceps brachii of rabbit were innervated two nerves, there were many anastomoses between them. Motor endplate bands were Vshaped on venlral and sagittal plane view.