Dr Praveen Kumar Agrawal is teaching live on Unacademy Plus
Course: Locomotion and Movement -2 Lesson -5 Structure/organization of a Skeletal muscle DR. P. K. AGRAWAL M.Sc, PH.D., CSIR NET (JRF), SRF, GATE, FIAZ 20 Years of Pre-medical teaching experience Ex Faculty, Allen Career Institute, Kota Watch my Live Classes on Unacademy Plus
STRUCTURE OF A SKELETAL (STRIATED) MUSCLE . Each skeletal muscles is a separate organ, composed of thousands of cells, called muscle fibers. . The cells are called fibres because of their elongated shape. . Thus, muscle cell, myocyte and muscle fiber are different terms for the same structure. .Skeletal muscle also contains connective tissues surrounding muscle fibers, blood vessels and nerves. A skeletal muscle consists of individual muscle fibers (cells) bundled into fascicles. . Skeletal muscles consist of a large number of fasciculi (singl. fasciculus), which are wrapped by a connective tissue sheath, called epimysium. . Each individual fasciculus is covered by connective tissue sheath, called perimysium. . Each fasciculus in turn consists of many long muscle fibres, called myofibre.
Epimysium Organization of a skeletal muscle Epimysium Fascicle Perimysium Muscle fiber (cell) Mvofihril Endomysium Somatic motor neuron Blood capillary Endomysium Nucleus Muscle fiber Striations Sarcoplasm Myofibril
Myofibre (muscle cell or myocyte) . A myofibre actually represent a single muscle cell or myocyte. It is a typical eukaryotic cell It is about 40 to 100 mm in diameter. during embryonic development from the fusion of a hundred or more small mesodermal ells called myoblasts . Its cytoplasm is called sarcoplasm and ER as sarcoplasmic reticulum. The myocyte . Each myofibre internally contains long, parallel running rod like structures. These are . These remain suspended in the sarcoplasm. Its outer membrane is called sarcolemma, which is a true cell membrane. internally contains many mit chondria for the quick supply of energy. called myofibrils . Myofibrils are the basic structural units of skeletal muscles.
Mohs Neuaon Motos end Ptal (N) Junctiom Nuelaus Mt emi . Plasma Membrane Sarvolemma) E R T- tubule L tubule Cell structure of a myofibre (Myocyte)
Request! Regularly watch lessons. Please like, comment and recommend this lesson Watch my LIVE classes in Unacademy PLUS .Register for Rs. 1 only on Sunday. ALL THE BEST