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Quadrupedal Mechanics - Anatomy & Physiology (view source)
Revision as of 01:02, 20 June 2013
, 01:02, 20 June 2013→The contractile proteins of muscle
==='''The contractile proteins of muscle''' ===
==='''The contractile proteins of muscle''' ===
[[File:QMFig 4.2.jpg|thumb|'''Fig.4.2 Muscle structure 2''']]
To understand the nature of a muscular force, we must appreciate the molecular and filamentous structure of muscle. Muscle is a machine largely constructed from two proteins, actin and myosin. Actin can exist in a globular form of molecular weight 45,000 and a diameter of 5.5 nm, which readily aggregates to form a long filament (Fig. 4.2 d), each filament contains two strands of spherical actin molecules, twisted on each other.
To understand the nature of a muscular force, we must appreciate the molecular and filamentous structure of muscle. Muscle is a machine largely constructed from two proteins, actin and myosin. Actin can exist in a globular form of molecular weight 45,000 and a diameter of 5.5 nm, which readily aggregates to form a long filament (Fig. 4.2 d), each filament contains two strands of spherical actin molecules, twisted on each other.
:::::'''Fig.4.2 Muscle structure 2'''
:::::'''Fig.4.2 Muscle structure 2'''
::::::Skeletal muscle fibre in longitudinal section;
::::::Skeletal muscle fibre in longitudinal section;
::::::a, as visualised by the light microscope;
::::::a, as visualised by the light microscope;
::::::b & c, by the electron microscope; and
::::::b & c, by the electron microscope; and
::::::d, as reconstructed from crystallographic X-ray
::::::d, as reconstructed from crystallographic X-ray
==='''The appearance of muscle using electron microscopy'''===
==='''The appearance of muscle using electron microscopy'''===