Question

For each of the structures concerned with inner ear receptor organs A–E, select the most appropriate option from the list below.

1. The gelatinous partition of top of the

2. The sensory organ in the utricle. crista that closes *** the ampulla.

3. The membrane structure overlying the

4. The sensory organ in the semicircular receptor cells in the organ of Corti. canals.

5. The hair processes on receptor cells in the inner ear.

A. Crista ampullaris.

B. Otolith organ.

C. Cupula.

D. Stereocilia.

E. Tectorial membrane.

Answer 1

A. Option 4 The sensory organ in the semicircular canals. Each semicircular canal has an ampulla whose sense organ is stimulated by movement of endolymph caused by rotary accelerations of the head in the three spatial planes in which the semicircular canals lie.

B. Option 2 The sensory organ in the utricle. These sensory organs are stimulated by linear accelerations of the head that modify the pull of the otoliths on the hair cells of the otolith organ.

C. Option 1 The gelatinous partition of top of the crista that closes *** the ampulla. When there is movement of fluid in the semicircular canals it causes deflections of the cupula that alter the output of impulses from the underlying crista ampullaris.

D. Option 5 The hair processes on receptor cells in the inner ear. These rod-shaped structures protrude from the hair cells and cause generator potentials when they are deformed by movement of endolymph.

E. Option 3 The membrane structure overlying the receptor cells in the organ of Corti. This structure which overlies the organ of Corti may be involved in bending of hair cells when the basilar membrane is made to vibrate with incoming sound waves.