myofibril

noun

myo·​fi·​bril ˌmī-ə-ˈfī-brəl  -ˈfi- 

: any of the longitudinal parallel contractile elements of a muscle cell that are composed of myosin and actin

myofibrillar

ˌmī-ə-ˈfī-brə-lər 

adjective

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

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

Word History

Etymology

New Latin myofibrilla, from my- + fibrilla fibril

First Known Use

1898, in the meaning defined above

Kids Definition

myofibril

noun

myo·​fi·​bril ˌmī-ō-ˈfīb-rəl  -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

myofibrillar

-rə-lər 

adjective