Sarcolemma

The sarcolemma also called the myolemma, is the cell membrane of a striated muscle fiber cell. It consists of a plasma membrane, which is a lipid bilayer, and an outer coat consisting of a thin layer of polysaccharide material (glycocalyx) that contacts the basement membrane, which contains numerous thin collagen fibrils . Sometimes called the myolemma, the sarcolemma is similar to a typical plasma membrane but has specialized functions for the muscle cell. Looking for online definition of sarcolemma in the Medical Dictionary?

Meaning of sarcolemma medical term.

What does sarcolemma mean? Within the sarcoplasm of each individual muscle fibre are approximately 0to 0myofibrils. Composed of the contractile proteins actin and myosin, the myofibrils represent the smallest units . In addition to the housekeeping functions of a cell plasma membrane, the sarcolemma is directly involved in synaptic transmission, action potential propagation, and excitation-contraction coupling . Once a signal from a motor neuron has passed the NMJ, it must be spread throughout the muscle fiber as an action potential that is propagated along the sarcolemma and into the T-tubular system.

The electrical activity of the sarcolemma must faithfully reproduce the activity of the innervating axon if the resulting contraction . THE functions of the sarcolemma of skeletal muscle are still uncertain, because of our lack of knowledge of its structure and detailed distribution over the entire surface of the muscle cell.

Most of our knowledge is derived from electron microscope investigations and the sarcolemma is regarded as a semi-permeable unit . Define sarcolemma : the membrane enclosing a striated muscle fiber. Englisch-Deutsch-Übersetzung für sarcolemma im Online-Wörterbuch dict. Sarcolemma definition, the membranous sheath of a muscle fiber.

The neuromuscular junction. The terminal bouton has numerous neurotransmitter vesicles that contain acetylcholine (ACh). The vesicles aggregate at active . Calcium channels of the sarcolemma and the sarcoplasmic reticulum play a key integrative role in determining and fine tuning the ionic free calcium concentration of the sarcoplasm and regulation of muscle function. Changes in the free ionic calcium concentration can lead to (1) force development and motion, (2) heat . The cell membrane is called the sarcolemma. The sarcoplasm of the cell is filled with contractile myofibrils and this in the nuclei and other organelles being relegated to the edge of the cell.

Myofibrils are contractile units within the cell which consist of a . Definition of sarcolemma - the fine transparent tubular sheath which envelops the fibres of skeletal muscles. The thin, transparent, extensible membrane covering every striated muscle fiber. Satellite cells are described as quiescent myoblasts and neighbor muscle fiber sarcolemma.

The absence of dystrophin permits excess calcium to penetrate the sarcolemma (the cell membrane). Duchenne muscular dystrophy. Exertional rhabdomyolysis from damage to the intercellular proteins . A thin cell membrane that surrounds a striated muscle fibre . Some authors, however, prefer to use the term sarcolemma to describe the skeletal muscle plasmalemma alone. The composition of the basement membrane has been investigated with immunohistochemical techniques.

Our approach was to first identify specific markers for the sarcolemma using immunofluorescence localization of a library of monoclonal antibodies isolated from mice immunized . This is the only enzyme . Excitation-Contraction (EC) Coupling. Action potential generated and propagated along sarcomere to. The hypothesis of the sarcolemma being overly permeable to extracellular fluid calcium is supported by the observation that MH is more common in cold- acclimated than in warm-acclimated humans.

However, Mickelson has reported that calcium . Synonyms: Definition: The outer membrane of a muscle cell, consisting of the plasma membrane, a covering basement membrane (about 1nm thick and sometimes common to more than one fiber), and the associated loose network of collagen fibers.