Muscular architecture and distribution of intramuscular nerves and motor endplates in muscle flexor digitorum profundus of rabbit

Objective: To investigate the relationship between muscular architecture and distribution of intramuscular nerves and motor endplates of muscle flexor digitorum profundus in rabbits.Methods: Muscle architecture method,modified Sihler's staining and acetylcholinesterase staining were used.Results: Muscle flexor digitorum profundus in rabbit was ring pennate.Muscle weight:(2.30±0.02)g,muscle fiber length:(1.00±0.01)cm,and physiologic cross-sectional area:(2.17±0.12)cm~2.In origin of muscle,the nerve main trunk had medial and lateral primary branches on fascia plate.Primary branches were divided into numerous secondary branches.Some secondary branches perforated fascia plate and innervated opposite muscle fibers.Motor endplate band was line-shaped and located in 2 edges of the muscle.After 2 bands encountering,they formed V-shaped motor endplate band in insertion of muscle.Conclusion: Muscle flexor digitorum profundus is ring pennate in rabbit,implying a design towards high force production.Perforating innervation exists in intramuscular nerve branches.Distributions of intramuscular nerves and motor endplates of muscle flexor digitorum profundus of rabbit are related to spatial arrangement of the muscle fibres.The muscle flexor digitorum profundus can be divided into compartment.