Understanding Senses: Olfaction, Gustation, Hearing, and Equilibrium

These flashcards cover key vocabulary related to the special senses discussed in the lecture notes, including olfaction, gustation, hearing, and equilibrium.

Olfaction

The sense of smell.

Gustation

The sense of taste.

Chemoreceptors

Receptors that detect chemical stimuli for smell and taste.

Olfactory epithelium

The organ of smell, located in the roof of the nasal cavity.

Olfactory sensory neurons

Bipolar neurons in the olfactory epithelium that detect odors.

Taste buds

Sensory organs located on the tongue that detect taste.

Gustatory epithelial cells

Taste receptor cells found in taste buds.

Papillae

Epithelial projections on the tongue associated with taste buds.

Basal epithelial cells

Stem cells in taste buds that divide every 7–10 days.

Sweet taste

One of the basic taste sensations, responds to sugars and certain amino acids.

Sour taste

Taste sensation caused by hydrogen ions in solution.

Salty taste

Taste sensation produced by metal ions, particularly sodium chloride.

Bitter taste

Taste sensation that responds to alkaloids and other compounds.

Umami taste

Taste sensations associated with amino acids like glutamate and aspartate.

Generator potential

A depolarization that occurs when a sensory receptor is stimulated.

Filaments of olfactory nerves

Bundles of nonmyelinated axons that carry signals from the olfactory epithelium.

Afferent fibers

Nerve fibers that carry sensory information towards the central nervous system.

Olfactory pathway

Pathway that olfactory information takes from the receptors to the brain.

Mitral cells

Second-order neurons in the olfactory bulb that relay signals from olfactory receptors.

Glomeruli

Structures in the olfactory bulb where olfactory nerve fibers synapse.

Cerebral cortex

Part of the brain where olfactory information is interpreted.

Limbic system

Part of the brain involved in emotional responses to smells.

Spiral organ

Organ of Corti responsible for translating sound vibrations into neural signals.

Auricle (pinna)

The external part of the ear that collects sound waves.

Auditory ossicles

Three small bones in the middle ear (malleus, incus, stapes) that transmit sound vibrations.

Tympanic membrane

Also known as the eardrum, it vibrates in response to sound waves.

Cochlear duct

The part of the cochlea that contains endolymph and houses the spiral organ.

Stereocilia

Hair-like projections on hair cells in the cochlea that transduce sound vibrations.

Vestibular apparatus

Structure in the inner ear that controls balance and equilibrium.

Cristae ampullares

Sensory organs located in the semicircular canals that respond to rotational movement.

Maculae

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

Endolymph

Fluid within the membranous labyrinth of the inner ear.

Perilymph

Fluid found in the bony labyrinth of the inner ear.

Frequency

The number of waves that pass a point in a given time; relates to pitch.

Amplitude

The height of sound waves, related to perception of loudness.

Decibels (dB)

The unit of measurement for sound intensity.

Synapse

The junction where communication occurs between neurons.

Action potentials

Electrical impulses that carry information along neurons.

Functional anatomy of the cochlea

The structure of the cochlea, including the basilar membrane and hair cells.

Acoustic meatus

Canal leading from the outer ear to the eardrum.

Semicircular canals

Structures in the inner ear that help with balance and detecting head rotation.

Facial nerve (VII)

Cranial nerve that carries taste impulses from the anterior two-thirds of the tongue.

Glossopharyngeal nerve (IX)

Cranial nerve that carries taste impulses from the posterior third of the tongue.

Vagus nerve (X)

Cranial nerve that transmits taste from the epiglottis.

Eustachian tube

Tube connecting the middle ear to the nasopharynx, helping to equalize pressure.

Acoustic reflex

Reflex that protects the inner ear from loud sounds.

Volatile odorants

Substances that must be in a gaseous state to be detected by olfactory receptors.

Taste pore

Opening in the taste bud through which tastants interact with gustatory hairs.

Cilia

Hair-like structures on olfactory receptors that help detect odors.

Nasal cavity

The space behind the nose that houses the olfactory epithelium.

Supporting cells

Cells in the olfactory epithelium that support sensory neurons.

Stria vascularis

Tissue in the cochlea that produces endolymph.

Maculae location

Found in the walls of the saccule and utricle.

Otoliths

Calcium carbonate crystals that help detect gravitational forces.

Kinocilium

A specialized cilium in the vestibular system involved in balance.

Hair cells

Sensory cells in the cochlea that detect sound vibrations.

Sound conduction pathway

Pathway that sound waves take from the outer ear to the cochlea.

Neurotransmitter

Chemical released by neurons to transmit signals to other neurons.

Taste discrimination

The ability to distinguish between different taste stimuli.

Rotational equilibrium

Balance maintained through the detection of head rotation.

Sensory adaptation

Diminished sensitivity to a constant stimulus over time.

Taste transduction

The process by which tastants cause depolarization and signal perception.

Generator potential

The change in membrane potential in response to sensory stimuli.

Crucial for smell identification

The process involving olfactory cilia binding odorants.

Vestibular system

Comprises structures in the inner ear that maintain balance.

Sensory neurons

Nerve cells that transmit sensory information to the central nervous system.