Muscle fibres: Difference between revisions
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Skeletal Muscle Fibres |
Cleaned up referencing. Added in some more links. |
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< | <span style="line-height: 1.5em;">The muscle cells in skeletal muscle are known as muscle fibres that have many [[mitochondria|mitochondria]] and [[Nuclei|nuclei]] distributed throughout. Each of the fibres contain multiple [[myofibrils |myofibrils]] that are made up of repeating units of the [[sarcomere|sarcomere]]. The sarcomere is made up of two sets of filaments; [[actin|actin]] (thin) and [[myosin|myosin]] (thick). There are distinct sections within the sarcomere:</span> | ||
*The A band: The centre section of the sarcomere. It contains the whole length of the myosin filaments including the overlap with the thin filaments | |||
*The I band: Only actin filaments are present | |||
*The M line: In the centre of the thick filaments, holding them together | |||
*The H zone: The centre of the A band that contains only the thick filaments | |||
*The Z line: The end of the sarcomere. It holds the thin filaments together | |||
The [[myosin|myosin]] filaments have a long tail and a globular head which attaches to actin during contraction. The actin filaments consist of two F actin strands coiled into a double helix. Tropomyosin and troponin are wound around the double helix to give the overall structure of the thin filaments<ref>[Rhoades R., Pflanzer R. (1996) Human Physiology, 3rd edition, Orlando: Saunders College Publishing] Pages 472-474</ref>.<br> | |||
=== Reference<br> === | |||
<references /> | |||
Revision as of 01:39, 26 November 2013
The muscle cells in skeletal muscle are known as muscle fibres that have many mitochondria and nuclei distributed throughout. Each of the fibres contain multiple myofibrils that are made up of repeating units of the sarcomere. The sarcomere is made up of two sets of filaments; actin (thin) and myosin (thick). There are distinct sections within the sarcomere:
- The A band: The centre section of the sarcomere. It contains the whole length of the myosin filaments including the overlap with the thin filaments
- The I band: Only actin filaments are present
- The M line: In the centre of the thick filaments, holding them together
- The H zone: The centre of the A band that contains only the thick filaments
- The Z line: The end of the sarcomere. It holds the thin filaments together
The myosin filaments have a long tail and a globular head which attaches to actin during contraction. The actin filaments consist of two F actin strands coiled into a double helix. Tropomyosin and troponin are wound around the double helix to give the overall structure of the thin filaments[1].
Reference
- ↑ [Rhoades R., Pflanzer R. (1996) Human Physiology, 3rd edition, Orlando: Saunders College Publishing] Pages 472-474