: any of the repeating, contractile, structural subunits of striated muscle cells (as of skeletal or cardiac muscle) that are composed of the protein filaments actin and myosin
Basically, during contraction a sarcomere shortens like a collapsing telescope, as the actin filaments at each end of a central myosin filament slide toward the myosin's center. Jesper L. Andersen et al.
see z line
Example Sentences
Recent Examples on the WebMore myofibrils will increase the mass of a muscle cell while more sarcomeres will increase the length.Popular Science, 1 Jan. 2019 Our bodies rebuild these tears by adding either sarcomeres, which are fibrous proteins inside muscle cells, or myofibrils—chains of rod-like units also in muscle cells that give them their striped appearance.Popular Science, 1 Jan. 2019 The basic functional units of muscle tissue are called sarcomeres. Alexa Tucker, SELF, 19 Aug. 2018
Word History
Etymology
sarco- + -mere
First Known Use
1891, in the meaning defined above
Medical Definition
sarcomere
noun
sar·co·mere ˈsär-kə-ˌmi(ə)r
: any of the repeating, contractile, structural subunits of striated muscle cells (as of skeletal or cardiac muscle) that are composed of the protein filaments actin and myosin
Skeletal muscle is a unique kind of tissue, made up of long, thin fibers composed of several different proteins. These proteins interlock like Legos inside fibrous compartments called sarcomeres. Gretchen Reynolds, The New York Times Sports Magazine
Basically, during contraction a sarcomere shortens like a collapsing telescope, as the actin filaments at each end of a central myosin filament slide toward the myosin's center. Jesper L. Andersen et al., Scientific American