October 2026 - Special Senses Study Guide

Core ideas to know

Learn the relationships, not a string of isolated definitions. These are the facts that let you reason through unfamiliar wording.

• Vision: light passes through cornea, pupil, lens and vitreous humor before reaching rods and cones in the retina.
• Hearing: sound vibrates the tympanic membrane, then the malleus, incus and stapes transmit it to the fluid-filled cochlea.
• Equilibrium: semicircular canals detect rotational movement; the utricle and saccule detect linear acceleration and head position.
• Taste: receptor cells in taste buds respond to dissolved chemicals and contribute to flavour alongside smell.
• Smell: olfactory receptors in the upper nasal cavity send signals through cranial nerve I to the olfactory bulb.

A reliable way to answer

Use the same short process every time so the wording of the question does not decide your method for you.

1. Identify the stimulus—light, vibration, head movement or dissolved chemical.
2. Trace the stimulus through the structures in physical order to its receptor.
3. Locate transduction, where receptor cells turn the stimulus into a nerve signal.
4. Name the nerve or brain pathway only after the receptor and stimulus are clear.

Distinctions that earn marks

Terms to know

Transduction

Conversion of a physical or chemical stimulus into an electrical signal.

Retina

Light-sensitive neural layer at the back of the eye.

Cochlea

Spiral inner-ear structure containing receptors for hearing.

Key points

• The retina converts light, while the cochlea converts sound vibration.
• The ossicles amplify and transmit vibration; they do not contain hearing receptors.
• Taste and smell both use chemoreceptors and work together to produce flavour.