Special Senses and Eye & Ear Anatomy

Vocabulary flashcards covering key terms related to olfaction, gustation, ear anatomy and function, and eye anatomy and optics.

Special Senses

The four senses—vision, hearing, taste, and smell—that have highly specialized organs.

Olfaction

The sense of smell produced by detection of airborne chemicals in the nasal cavity.

Olfactory Receptors

Chemoreceptors in the nasal mucosa that bind odor molecules dissolved in mucus.

Olfactory Organs

Structures for smell, including the olfactory epithelium in the superior nasal cavity and the olfactory bulb in the brain.

Gustation

The sense of taste generated by chemical molecules dissolved in saliva.

Taste Buds

Clusters of specialized epithelial cells (taste receptors) located mainly on tongue papillae that detect taste stimuli.

Primary Taste Sensations

The five basic tastes: sweet, sour, salty, bitter, and umami (savory).

Sections of the Ear

The three anatomical divisions: outer ear, middle ear, and inner ear.

Outer Ear

Composed of the pinna (auricle), external auditory canal, and tympanic membrane, it collects and channels sound waves.

Middle Ear

Air-filled cavity containing the ossicles—malleus, incus, stapes—that amplify and transmit vibrations.

Eustachian Tube

Canal connecting the middle ear to the pharynx that equalizes air pressure across the eardrum.

Cochlea

Spiral-shaped inner-ear structure that converts sound vibrations into neural impulses.

Semicircular Canals

Three fluid-filled loops in the inner ear that detect rotational head movements for dynamic equilibrium.

Vestibule

Central inner-ear chamber that senses head position relative to gravity for static equilibrium.

Oval Window

Membrane where the stapes delivers vibrations into the cochlea.

Round Window

Membrane that permits fluid displacement within the cochlea, aiding wave propagation.

Spiral Organ (Organ of Corti)

Sensory structure inside the cochlea whose hair cells transduce mechanical sound waves into electrical signals.

Auditory Pathway

Route from hair-cell activation → cochlear branch of CN VIII → brainstem → thalamus → auditory cortex for sound perception.

Static Equilibrium

Maintenance of body position when stationary, detected by the vestibule.

Dynamic Equilibrium

Maintenance of balance during motion, sensed by the semicircular canals.

Accessory Organs of Sight

Supporting eye structures: eyelids, eyelashes, lacrimal glands, and six extrinsic eye muscles.

Lacrimal Gland

Gland that secretes tears to lubricate the eye and flush debris.

Lysozyme

Antibacterial enzyme in tears that destroys bacterial cell walls.

Extrinsic Eye Muscles

Six muscles (superior, inferior, medial, lateral recti; superior, inferior obliques) controlling voluntary eye movement.

Cornea

Transparent anterior layer allowing light entry and contributing to focusing.

Sclera

Opaque white outer layer providing protection and shape to the eye.

Choroid

Middle-tunic layer rich in blood vessels that nourishes ocular tissues.

Ciliary Body

Ring of muscle that adjusts lens shape and produces aqueous humor.

Iris

Colored diaphragm regulating pupil size and light entry.

Lens

Biconvex structure that focuses light on the retina by changing shape (accommodation).

Pupil

Central opening in the iris; constricts in bright light, dilates in dim light.

Aqueous Humor

Clear fluid between cornea and lens that nourishes tissues, maintains pressure, and refracts light.

Vitreous Humor (Vitreous Body)

Gel filling the posterior eye chamber, supporting shape and holding retina in place.

Inner Tunic

Innermost layer consisting of the retina and optic nerve with photoreceptors.

Rods

Retinal photoreceptors sensitive to low light, enabling night and grayscale vision.

Cones

Retinal photoreceptors responsible for color vision and sharp detail in bright light.