BIOL 171 Lecture Notes - Lecture 7: T-Tubule, Myocyte, Endoplasmic Reticulum
Document Summary
Muscles attached to bone, skin or fascia (fibrous tissue layer) alternating light and dark bands (striations (ridges)) on cells under voluntary control. Muscle functions give shape produce movement maintain posture support other structure generate heat regulate organ volumes (sphincters: circular muscles that maintain constriction of opening) Properties of muscle tissue excitability conductivity contractility extensibility elasticity. Composition skeletal muscles are composed of bundles of muscle fibre called fascicles fascicles consist of bundles of elongated, striated muscle cells (muscle fibres) Connective tissue components epimysium perimysium surrounds entire muscle surrounds individual fascicles endomysium surrounds individual muscle fibres all connective tissue layers extend beyond the muscle belly to form the tendon tendon attaches muscle to bone. Sarcoplasm (sarco = muscle) most of volume occupied by myofibrils also contains glycogen and myoglobin (red-coloured protein that binds oxygen) Transverse tubules invaginations of sarcolemma (cell membrane) carry muscle action potentials deep into sarcoplasm ensures that action potential is transmitted across entire cell and into centre.
