Neuroscience Special Senses

Olfaction

The process of smell, initiated by olfactory receptors in the nasal cavity.

Olfactory Nerve (CN1)

The cranial nerve responsible for the sense of smell.

Anosmia

Loss of the sense of smell, often due to bilateral lesions.

Gustation

The process of taste, primarily occurring through taste buds on the tongue.

Facial Nerve (CN7)

The cranial nerve involved in the sensation of taste from the anterior two-thirds of the tongue.

Therapeutic significance of olfactory stimulation

Olfaction can enhance CNS arousal and mood, particularly in comatose patients.

Visual Receptor Pathway

Pathway through which light waves are converted into action potentials and interpreted by the visual cortex.

Optic Nerve (CN2)

The cranial nerve transmitting visual information from the retina to the brain.

Contralateral homonymous hemianopia

Loss of visual field in the same side of both eyes, affecting either the right or left field.

Nystagmus

Involuntary, rapid, repetitive movement of the eyes that can indicate vestibular dysfunction.

Equilibrium and Balance

Functions governed by the vestibular system, involving the vestibulocochlear nerve.

Hearing Impairment

Can be sensorineural (inner ear or nerve damage) or conductive (outer/inner ear obstruction).

Cortical deafness

Hearing loss resulting from damage to the primary auditory cortex.

Vestibular apparatus

The sensory organ in the inner ear responsible for balance.

Vestibulospinal tract

Pathway that helps maintain balance and posture by relaying sensory information from the vestibular system.

Signs of Vestibular Dysfunction

Can include nystagmus, vertigo, tinnitus, hearing loss, and balance issues.