Rod Outer Segment

**Semantic type:** Cell Component

**Definition:** A portion of the retinal rod cell largely consisting of a stack of discs (membrane infoldings that are incompletely separated in cones) that are continually replenished near the inner segment and that are shed from the distal end and phagocytosed by the pigmented epithelium.

**Synonyms:** - Rod Outer Segment of the Retina - Rod Outer Segments