The part of the mammalian ear responsible for the maintenance of balance is the

Analyze the question: The question asks which part of the mammalian ear helps maintain balance (equilibrium), not hearing.

Explain the concept: The mammalian ear has three main regions:

• Outer ear: pinna and ear canal. They collect sound waves.
• Middle ear: eardrum and three ossicles (malleus, incus, stapes). They transmit and amplify vibrations.
• Inner ear: the cochlea (for hearing) and the vestibular system (for balance).

The vestibular system consists of the semicircular canals, the utriculus and the sacculus. These contain fluid (endolymph) and sensory hair cells.

• The semicircular canals detect rotational movement of the head.
• The utriculus and sacculus detect the position of the head and linear movement, relative to gravity.

Solution (checking each option):

• A. Cochlea: a coiled tube that converts sound vibrations into nerve impulses. It is for hearing, not balance.
• B. Pinna: the external ear flap that collects sound. It plays no part in balance.
• C. Perilymph: a fluid that surrounds the membranous labyrinth of the inner ear. It is a fluid, not the organ that regulates balance.
• D. Vestibular system: includes the semicircular canals, utriculus and sacculus. This is the part responsible for balance.

Answer: The correct option is D. vestibular system.

Exam tip: Link the words: Cochlea = Concert (hearing), Vestibular = Vertical/Variation in position (balance). If a JAMB question mentions "balance" or "equilibrium" in the ear, think of the semicircular canals/vestibular apparatus.