Question

what do a, b and c represent? what fluid is present in them?
model of the inner car with arrow a pointing to fluid filled bony circular structure, arrow b pointing to a membranes sac that connects with the circular structure and arrow c pointing to small membranous sac extending into the snail shaped structure.
bony labyrinth:perilymph
membranous labyrinth:endolymph
membranous labyrinth:csf
bony labyrinth:otoliths

Explanation:

• The bony labyrinth (A) is a fluid - filled bony circular structure in the inner ear. The fluid present in it is perilymph.
• The membranous labyrinth (B and C) is a membrane - lined structure within the bony labyrinth. The fluid present in the membranous labyrinth is endolymph. CSF (cerebrospinal fluid) is not present in the inner ear labyrinths. Otoliths are small calcium carbonate crystals in the inner ear (in the utricle and saccule of the membranous labyrinth) but not a fluid.

Answer:

A. Bony labyrinth: Perilymph, B. Membranous labyrinth: Endolymph, C. Membranous labyrinth: Endolymph