muscle fibres


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Figure 1: The autonomic nervous system. Actions on secretory functions (heart diagrams indicate release into the circulation). Sympathetic actions on the left and parasympathetic actions on the right. Solid arrows: stimulation (contraction or secretion); broken arrows: inhibition.

muscle fibres

the muscle cells. Usually refers to skeletal muscle, which has greatly elongated (fibre-like) cells, up to 15-20 cm in the largest muscles of the human body. Each skeletal muscle fibre has many nuclei (more than 2000 in the largest fibres), located, after initial development, just beneath the cell membrane. These nuclei cannot divide; skeletal muscle growth and repair depend on satellite cells. The term 'muscle fibre' may also be applied to the much smaller cells of smooth and cardiac muscle, which have one central nucleus. All types of muscle fibre have longitudinally oriented contractile filaments containing actin and myosin. Each skeletal muscle fibre receives its own branch of a motor nerve, but cardiac and smooth muscle fibres are innervated in looser groupings. See also myofibrils, sarcoplasmic reticulum; Figure 1.
References in periodicals archive ?
Grade 3: This is the most severe calf strain with a complete tearing or rupture of muscle fibres in the lower leg.
Effect of postrigor sarcomere length on mechanical and structural characteristics of raw and heat-denatured single pork muscle fibres.
That's up against folk whose muscle fibres had the genetic equivalent advantage of an Eton education, a fifty grand a year trust fund and an internship at a merchant bank.
Although the relation between the WB values and muscle fibre characteristics is unclear (Sazili et al.
But when they used ultrasound to measure the muscle fibre length in the women's calf muscles, they saw that the high heel wearers' muscle fibres were 13 per cent shorter than those of the flat shoe users, according to study results published in the Journal of Experimental Biology on Thursday.
A mean of 679 [+ or -] 68 muscle fibres were classified as type I, IIA, or IIX, from each sample (Staron 1997).
The device is an arch of silicon with a cord of heart muscle fibres attached underneath The microrobot is propelled as the muscle fuelled by a simple glucose nutrient contracts and relaxes, reports New Scientist.
The MLC statement reporting the findings notes "these cattle were slaughtered at higher fat levels so the results are not directly comparable" -- but breed enthusiasts would say the fat level is irrelevant if muscle fibre is the factor being evaluated.
The thirteen titles carry fully descriptive titles; Composition and structure; Muscle cell differentiation and growth; Proteins of thick filament; Proteins of the thin filament - actin, tropomyosin and troponin; Cytoskeletal and other proteins of the myofibrils; Sacroplasmic reticulum; Contraction and rigor mortis; Skeletal muscle growth and protein metabolism; Skeletal muscle fibre types; Cardiac and smooth muscle; Sacroplasmic proteins; The connective tissues - collagen, elastin and ground substance; and Postmortem changes during conversion of muscle to meat.
A group of international researchers from the University of Texas, Dallas have developed artificial muscle fibres from nylon sewing thread and polyethylene fishing line, which has the capability to replace the expensive and much weaker synthetic muscles that are produced today.