- 1. Resembling muscle. 2. One of the fine, contractile, threadlike protoplasmic elements found in certain epithelial cells in lower animals. 3. A contractile part of retinal cones in certain fish and amphibia. In mammals, the m. is the inner part of the inner segment of rods and cones; it contains microtubules, the Golgi apparatus, endoplasmic reticulum, and ribosomes, but no myofibrils. [myo- + G. eidos, appearance]
* * *my·oid 'mī-.ȯid adj resembling musclemyoid n an inner structural part of a retinal rod or cone containing numerous cell organelles
* * *my·oid (miґoid) [my- + -oid] 1. resembling or like a muscle. 2. a substance resembling muscle.
Medical dictionary. 2011.