Answer
The two sacs in the membranous labyrinth of the vestibule are the utricle and the saccule.
Work Step by Step
The cavity of the inner ear is called the labyrinth because it contains a number of complicated membranous canals. These comprise there separable structures: the semicircular canals, the cochlea and the vestibule.
The vestibule is an ovoid cavity with two membranous sacs suspended in the perilymph of the bony labyrinth, These two sacs are the utricle and the saccule. They contain potassium rich endolymph.They also contain small receptors (macula with otoliths) that respond to the pull of gravity and changes in head position. The utricle detects changes in linear acceleration and the
sacule detects changes in vertical acceleration of the head.
