TY - CHAP M1 - Book, Section TI - Neuromuscular Pathology A1 - Lee, Eric T. A1 - Chahin, Nizar A2 - Reisner, Howard M. PY - 2015 T2 - Pathology: A Modern Case Study AB - QUICK REVIEWOrganization of Skeletal MuscleNeuromuscular diseases include a wide-ranging variety of pathologies that can produce significant disability for the patient. The history and physical examination are very important in narrowing the differential, and the muscle biopsy provides an additional layer of granularity to assist in making the diagnosis. To understand muscle pathology, one must understand the organization of the skeletal muscle and the histochemical stains that provide the means necessary to distinguish between potential differentials (Figures 19-1 and 19-2).FasciclesPerimysium: Connective tissue surrounding the fasciclesEndomysium: Connective tissue surrounding the muscle fibers inside the fasciclesEpimysium: Connective tissue covers the outer surface of the muscleMuscle FibersMyofibrils: An elongated structure containing cytoskeletal elements allowing the muscle to contractSarcomere: Thick (myosin) and thin filaments (actin, troponin, tropomyosin)The striated muscle appearance is created by pattern of alternating dark and light bandsSarcolemma (Plasma Membrane)Sarcoplasma: Specialized cytoplasm of a muscle cellNuclei and mitochondria are located just beneath the sarcolemmaSarcoplasmic reticulum extends between the myofibrils SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1115281749 ER -