sarcomere
Sign in to saveAlso known as GO:0030017, sarcomeres
A sarcomere (Greek σάρξ sarx "flesh", μέρος meros "part") is the smallest functional unit of striated muscle tissue. It is the repeating unit between two Z-lines. Skeletal muscles are composed of tubular muscle cells (called muscle fibers or myofibers) which are formed during embryonic myogenesis. Muscle fibers contain numerous tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as alternating dark and light bands. Sarcomeres are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or r
Key facts
- Microanatomy.Name
- Sarcomere
- Microanatomy.Latin
- sarcomerum
- Microanatomy.Image
- sarcomere.gif
- Microanatomy.Caption
- Image of sarcomere
- Microanatomy.PartOf
- Striated muscle
via Wikipedia infobox
Research
13,924 papers- Targeting the sarcomere in inherited cardiomyopathies.Nature reviews. Cardiology · 2022
- Disruption of cTnT-Mediated Sarcomere-Mitochondrial Communication Results in Dilated Cardiomyopathy.Circulation · 2025
- Low Penetrance Sarcomere Variants Contribute to Additive Risk in Hypertrophic Cardiomyopathy.Circulation · 2025
- Muscle growth by sarcomere divisions.Science advances · 2025
- Sarcomere Dysfunction in Nemaline Myopathy.Journal of neuromuscular diseases · 2017
via PubMed
Wikidata facts
- Image
- Human skeletal muscle tissue 1 - TEM.jpg
Show 3 more facts
- Commons category
- Sarcomeres
- exact match
- purl.obolibrary.org/obo/GO_0030017
- native label
- sarcomerum
Sources (2)
via Wikidata · CC0
~9 min read
Article
6 sectionsContents
- Bands
- Contraction
- Rest
- Comparative structure
- References
- External links
A sarcomere (Greek σάρξ sarx "flesh", μέρος meros "part") is the smallest functional unit of striated muscle tissue. It is the repeating unit between two Z-lines. Skeletal muscles are composed of tubular muscle cells (called muscle fibers or myofibers) which are formed during embryonic myogenesis. Muscle fibers contain numerous tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as alternating dark and light bands. Sarcomeres are composed of long, fibrous proteins as filaments that slide past each other when a muscle contracts or relaxes. The costamere is a different component that connects the sarcomere to the sarcolemma.
Two of the important proteins are myosin, which forms the thick filament, and actin, which forms the thin filament. Myosin has a long fibrous tail and a globular head that binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement. Myosin can only bind to actin when the binding sites on actin are exposed by calcium ions.