BMS 501 Study Guide - Midterm Guide: Endoplasmic Reticulum, Elastic Fiber, Myocyte
Document Summary
Functions of muscle: excitability (responsiveness) contractility (ability of cells to shorten) extensibility (stretching, elasticity (recoil) Producing movement maintaining posture and body position supporting soft tissues. Guarding body entrances and exits maintaining body temperature storing nutrients. Epimysium layer of collagen fibers that surrounds the muscle, connected to deep fascia separates muscle from surrounding tissues. Perimysium surrounds muscle fiber bundles (fascicles) contains :collagen, fibers, elastic fibers, blood vessels nerves. Endomysium- surrounds individual muscle cells (muscle fibers) contains: capillary networks. Myosatellite cells (stem cells) that repair damage nerve fibers. Terminal cisterna- distribute action potentials throughout the interior of the skeletal muscle cell. Triad- translate the action potential from the plasma membrane to the sarcoplasmic reticulum, effecting calcium flow into the cytoplasm and the initiation of muscle contraction. T-tubles- is to conduct impulses from the surface of the cell down into the cell. Filamentous actin (f-actin: twisted strand composed of two rows of globular. G-actin molecules: active sites on g-actin bind to myosin.
