What are muscles?


Muscle is a soft tissue of animals. Muscle cells contain protein filaments that slide past one another, producing a contraction that changes both the length and the shape of the cell. Muscles function to produce force and cause motion. They are primarily responsible for maintenance of and changes in posture, locomotion of the organism itself, as well as movement of internal organs, such as the contraction of the heart and movement of food through the digestive system via peristalsis.

Read more about Muscles.

Some articles on muscles:

Lumbar Spinal Nerve 5 - Muscles
... L5 supplies many muscles, either directly or through nerves originating from L5 ... The muscles are gluteus maximus muscle mainly S1 gluteus medius muscle gluteus minimus muscle tensor fasciae latae tibialis anterior tibialis posterior extensor ...
Scissor Gait - Presentation
... in a scissors-like movement while the opposing muscles, the abductors, become comparatively weak from lack of use ... cerebral palsy, the individual is often also forced to walk on tiptoe unless the plantarflexor muscles are released by an orthaepedic surgical procedure ... and internal rotation at the hip progressive contractures of all spastic muscles complicated assisting movements of the upper limbs when walking ...
Muscles - Evolution
... Muscles have evolved at least twice, once in cnidaria and once in bilateria they seem to have evolved from contractile cells in sponge-grade organisms ... Evolutionarily, specialized forms of skeletal and cardiac muscles predated the divergence of the vertebrate/arthropod evolutionary line ... This indicates that these types of muscle developed in a common ancestor sometime before 700 million years ago (mya) ...
Skeletal Muscle - Physics
... Muscle force is proportional to physiologic cross-sectional area (PCSA), and muscle velocity is proportional to muscle fiber length ... is determined by a number of biomechanical parameters, including the distance between muscle insertions and pivot points and muscle size ... Muscles are normally arranged in opposition so that as one group of muscles contract, another group relaxes or lengthens ...
Central Governor - Hill
... we suggest that, in the body (either in the heart muscle itself or in the nervous system), there is some mechanism which causes a slowing of the circulation as soon as a serious degree of unsaturation occurs, and ... exercise fatigue was modeled in terms of it being due to a mechanical failure of the exercising muscles ("peripheral muscle fatigue") ... was caused either by an inadequate oxygen supply to the exercising muscles, lactic acid buildup, or total energy depletion in the exhausted muscles ...

Famous quotes containing the word muscles:

    What is this beast, she thought,
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    What is this moss on his legs?
    What prickly plant grows on his cheeks?
    What is this voice as deep as a dog?
    Anne Sexton (1928–1974)

    All of this,
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    Hilda Doolittle (1886–1961)

    Flashed from his matted head and marble feet,
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    With the coiled, hurdling muscles of his thighs:
    The corpse was bloodless, a botch of reds and whites,
    Robert Lowell (1917–1977)