noun
sacculus; saccule
Anatomical term for the smaller of the two otolith organs in the inner ear, involved in balance and detecting vertical acceleration.
球形嚢は内耳の前庭にある平衡感覚に関わる器官です。
The sacculus is an organ in the vestibule of the inner ear involved in the sense of balance.
The utricle, the larger otolith organ in the inner ear, also involved in balance but primarily sensitive to horizontal acceleration.
From 球形 (spherical) + 嚢 (sac, cyst), a calque of the Latin 'sacculus' (little sac).