Dr. ANAND SRINIVASAN

Collection of muscle fibers supported by connective tissue

Made of actin & myosin

Mesodermal origin

Special terms: Plasma membrane sarcolemma Cytoplasm sarcoplasm Smooth endoplasmic reticulum sarcoplasmic

reticulum Mitochondria sarcosomes

Three connective tissue layers :

Epimysium

Perimysium

Endomysium

Each muscle fiber is an elongated unbranched cylindrical cell.

Has many flat nuclei located beneath sarcolemma.

Has alternative dark A and light I bands with Z line intersecting I band.

Each muscle fiber made of myofibrils.

Non striated, elongated and spindle shaped

Found in the walls of hollow viscera e.g. GIT, blood vessels, uterine tube etc.,

Presence of cross striations & branching pattern

Nuclei in the center.

Presence of “intercalated discs”

Myasthenia Gravis Reduction in the number of Acetyl

Choline receptors.

Duchenne Muscular Dystrophy Mutation of “Dystrophin” protein located

in the sarcolemma

Chapter 6 – Microanatomy Workbook, RAKMHSU