Special Senses Supplementary Information

These flashcards cover key concepts regarding the special senses, their mechanisms of transduction, and related pathways.

What are the special senses?

The special senses are vision, taste, smell, hearing, and equilibrium.

What is visual transduction?

The process by which light is converted into signals in the brain during vision.

What are photoreceptors?

Cells in the retina that respond to light; include rods (for dim light) and cones (for color and detail).

What happens when photons hit rhodopsin?

Rhodopsin changes shape when 11-cis-retinal absorbs a photon and converts to all-trans-retinal.

What is the role of opsin in visual transduction?

Opsin activates a G-protein called transducin, which triggers a cascade of reactions leading to hyperpolarization of photoreceptors.

What is hyperpolarization in photoreceptors?

A process where photoreceptor cells become more negative, reducing neurotransmitter release when exposed to light.

What are bipolar cells' responses to glutamate changes?

ON bipolar cells are activated when glutamate decreases, while OFF bipolar cells are activated when glutamate increases.

What is the function of ganglion cells?

Ganglion cells generate action potentials based on the inputs from bipolar cells.

How does auditory transduction begin?

Sound waves enter the ear and travel through the external auditory meatus to the tympanic membrane.

What is tonotopy in the basilar membrane?

The property that different parts of the basilar membrane respond to different frequencies of sound.

What occurs at the organ of Corti during sound transduction?

Hair bundles bend when the basilar membrane moves, leading to the opening of mechanically gated channels.

What is the role of Ca²⁺ in hair cells?

Ca²⁺ influx triggers the release of neurotransmitters from the hair cells onto the auditory nerve fibers.

What is the central auditory pathway?

The pathway that sounds take from the cochlear nucleus to the primary auditory cortex, including multiple brainstem and thalamic nuclei.

What is static equilibrium?

A type of equilibrium that includes awareness of head position and posture in response to gravity.

What is dynamic equilibrium?

This type of equilibrium deals with balance during motion, such as turning or spinning.

What are maculae?

Receptors located in the utricle and saccule that detect linear acceleration and head position.

What is the uniqueness of olfactory transduction?

Olfactory signals do not relay through the thalamus before reaching the primary olfactory cortex.

What is the role of neurotransmitters in gustatory transduction?

Different taste receptor cells release specific neurotransmitters to signal different taste modalities to the brain.

What distinguishes bone conduction from air conduction?

Bone conduction transmits sound vibrations directly to the cochlea, bypassing the outer and middle ear, while air conduction involves sound traveling through the outer ear.

What are cochlear implants used for?

Cochlear implants create a new hearing pathway by directly stimulating the auditory nerve in individuals with severe hearing loss.