Myofilament


Myofilament
Myofilament
Myofilament.svg
Myofilament
Latin myofilamentum
Code TH H2.00.05.0.00006

Myofilaments, the filaments of myofibrils constructed from proteins,[1]. The principal types of muscle are striated muscle, obliquely striated muscle and smooth muscle. Various arrangements of myofilaments create different muscles. Striated muscle has transverse bands of filaments. In obliquely striated muscle, the filaments are staggered,and smooth muscle has irregular arrangements of filaments.

There are three different types of myofilaments: thick, thin, and elastic filaments.

  • Thick filaments consist primarily of the protein myosin. Each thick filament are approximately 15 nm in diameter, and each is made of several hundred molecules of myosin.
  • Thin filaments, 7 nm in diameter, consist primarily of the protein actin. All thin filaments are attached the Z disc.
  • Elastic filaments, 1 nm in diameter, are made of titin, a large springy protein. They flank each thick filament and anchor it to the Z disc, the end point of a sarcomere.


The protein complex composed of actin and myosin, contractile proteins, is sometimes referred to as "actomyosin". In striated muscle, such as skeletal and cardiac muscle, the actin and myosin filaments each have a specific and constant length in the order of a few micrometers, far less than the length of the elongated muscle cell (a few millimeters in the case of human skeletal muscle cells). The filaments are organized into repdeated subunits along the length of the myofibril. These subunits are called sarcomeres.

References

  1. ^ "myofilament" at Dorland's Medical Dictionary

2. Muscle :: Diversity of Muscle -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 3. Saladin, Kenneth S. "Myofilaments." Anatomy & Physiology: the Unity of Form and Function. 5th ed. New York: McGraw-Hill, 2010. 406-07. Print.

External links


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Look at other dictionaries:

  • myofilament — noun Date: 1949 one of the individual filaments of actin or myosin that make up a myofibril …   New Collegiate Dictionary

  • Myofilament — Mikrofilamente in Fibroblasten der Maus, fluoreszenzmikroskopisch dargestellt Mikrofilamente sind fadenförmige Protein Strukturen in eukaryotischen Zellen. Zusammen mit den Mikrotubuli und Intermediärfilamenten bilden sie die Hauptmasse des …   Deutsch Wikipedia

  • myofilament — /muy euh fil euh meuhnt/, n. Cell Biol. a threadlike filament of actin or myosin that is a component of a myofibril. [1945 50; MYO + FILAMENT] * * * …   Universalium

  • myofilament — noun A filament within a myofibril, constructed from proteins …   Wiktionary

  • myofilament — myo·fil·a·ment fil ə mənt n one of the individual filaments of actin or myosin that make up a myofibril * * * myo·fila·ment (mi″o filґə mənt) [myo + filament] any of the numerous ultramicroscopic threadlike structures occurring in …   Medical dictionary

  • myofilament — myo·filament …   English syllables

  • myofilament —  n.m. Filament constitutif de la myofibrille …   Le dictionnaire des mots absents des autres dictionnaires

  • myofilament — ˌ noun Etymology: my + filament : one of the individual filaments of actin or myosin that make up a myofibril * * * /muy euh fil euh meuhnt/, n. Cell Biol. a threadlike filament of actin or myosin that is a component of a myofibril. [1945 50; MYO …   Useful english dictionary

  • muscle filament — myofilament …   Medical dictionary

  • Actin — G Actin (PDB code: 1j6z). ADP and the divalent cation are highlighted …   Wikipedia


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