myofibril
noun
myo·fi·bril
ˌmī-ə-ˈfī-brəl 
-ˈfi-
-ˈfi-
: any of the longitudinal parallel contractile elements of a muscle cell that are composed of myosin and actin
Examples of myofibril in a Sentence
Recent Examples on the Web
Sarcoplasmic and myofibril types are the two main categories under which this process falls.
—
Amber Smith, Discover Magazine, 12 Oct. 2022
More myofibrils will increase the mass of a muscle cell while more sarcomeres will increase the length.
—Popular Science, 1 Jan. 2019
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Amber Smith, Discover Magazine, 12 Oct. 2022
More myofibrils will increase the mass of a muscle cell while more sarcomeres will increase the length.
—Popular Science, 1 Jan. 2019
Cite this Entry
“Myofibril.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/myofibril. Accessed 3 Nov. 2025.
Copy CitationKids Definition
myofibril
noun
myo·fi·bril
ˌmī-ō-ˈfīb-rəl
-ˈfib-
-ˈfib-
: any of the long thin contracting protein subunits of a muscle cell that are composed of actin and myosin filaments
Medical Definition
myofibril
noun
myo·fi·bril
ˌmī-ō-ˈfīb-rəl, -ˈfib-
: one of the longitudinal parallel contractile elements of a muscle cell that are composed of myosin and actin
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