Home   Chapter Home   Jobs   Conferences   Fellowships   Books



Advertisement

Soft tissue tumors

Skeletal muscle

Skeletal muscle-normal


Reviewer: Vijay Shankar, M.D. (see Reviewers page)
Revised: 18 February 2013, last major update November 2012
Copyright: (c) 2003-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================

● Normal skeletal muscle arises from mesectoderm in head and neck and from myotomes (group of skeletal muscles supplied by a specific segmental spinal nerve), and elsewhere via formation of myoblasts and myotubes (muscle fibers)
● Contains myofibrils composed of thin (actin) and thick (myosin) filaments

Terminology
=========================================================================

● Skeletal muscle cells are also called myofibers or myocytes

Embryologic images
=========================================================================



Various images

Diagrams
=========================================================================



Various images


Section of myofibrils with sarcoplasmic reticulum (SR) and T-tubules (T)

Various images

Micro description
=========================================================================

● Long cylindrical cells, unbranched and striated
● Multinucleated syncytia, formed by fusion of single cells
● Nuclei are peripheral to the myofiber

Micro images
=========================================================================


Various images

Longitudinal and transverse sections

Skeletal muscle vasculature

Normal striated muscle

Electron microscopy description
=========================================================================

● Electron microscopy reveals structural components:
I (isotropic) band: thin filaments only
A (anisotropic) band: overlapping thin and thick filaments
H band: thick filaments only
Z line: divides center of I band; serves as attachment site for the sarcomere, the repeating individual unit of the muscle fiber

Electron microscopy images
=========================================================================



Various images

Additional references
=========================================================================

Wikipedia, Slideshow of the sliding filament model (ppt)

End of Soft tissue tumors > Skeletal muscle > Skeletal muscle-normal


This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).