The Special Senses Cram Study Guide Flashcards

Vocabulary flashcards covering the accessory structures, tunics, vision mechanics, phototransduction, olfaction, gustation, auditory pathway, and equilibrium structures from the special senses lecture.

Eyebrows

Accessory structures of the eye that divert sweat and water away from the eyes.

Eyelids

Accessory structures that protect the eye and spread tears across the surface through blinking.

Eyelashes

Accessory structures that detect foreign objects touching the eye and trigger the blink reflex.

Conjunctiva

A protective membrane covering the eye that lubricates and protects the ocular surface.

Lacrimal apparatus

System responsible for producing and draining tears.

Lysozyme

An antibacterial enzyme present in tears that helps protect the eye from infection.

Lateral rectus

Extrinsic eye muscle that abducts the eye; innervated by CN VI (Abducens).

Superior oblique

Extrinsic eye muscle that moves the eye down and lateral; innervated by CN IV (Trochlear).

Fibrous tunic

Outermost layer of the eye consisting of the sclera and cornea.

Sclera

Part of the fibrous tunic that protects the eye, maintains its shape, and anchors extrinsic eye muscles.

Cornea

Transparent anterior part of the fibrous tunic that performs most of the light refraction.

Vascular tunic

Middle layer of the eye comprising the choroid, ciliary body, and iris.

Choroid

Part of the vascular tunic that provides nourishment to the eye.

Ciliary body

Structure in the vascular tunic that changes lens shape for focus and helps produce aqueous humor.

Iris

Pigmented portion of the vascular tunic that controls pupil diameter.

Neural tunic

Innermost layer (retina) containing photoreceptors (rods and cones), bipolar cells, and ganglion cells.

Anterior cavity

Region in front of the lens containing aqueous humor, which nourishes the cornea and lens while maintaining pressure.

Posterior cavity

Region behind the lens containing vitreous humor, a gel that maintains eye shape and supports the retina.

Aqueous humor

Fluid found in the anterior cavity that nourishes the cornea and lens and maintains intraocular pressure.

Vitreous humor

Gel-like substance in the posterior cavity that maintains eye shape and supports the retina.

Rods

Photoreceptors specialized for dim/night light and peripheral vision with high sensitivity, low detail, no color vision, containing rhodopsin.

Cones

Photoreceptors specialized for bright/day light, color vision, and high detail, densely concentrated in the fovea centralis and containing photopsins.

Emmetropia

Normal vision in which light images focus directly on the retina.

Myopia

Nearsightedness where images focus in front of the retina; corrected using a concave lens.

Hyperopia

Farsightedness where images focus behind the retina; corrected using a convex lens.

Astigmatism

Distorted or blurry vision caused by an uneven curvature of the cornea or lens.

Glaucoma

Condition characterized by elevated intraocular pressure that can cause damage to the optic nerve.

Presbyopia

Age-related loss of lens elasticity causing difficulty in focusing on near objects.

Bleaching

Process where exposure to light causes rhodopsin to separate into opsin and retinal.

Olfactory epithelium

Tissue in the superior nasal cavity containing olfactory receptor cells, supporting cells, and basal cells.

Filiform papillae

Most numerous lingual papillae that serve a mechanical role and contain NO taste buds.

Fungiform papillae

Mushroom-shaped papillae on the tongue that contain taste buds.

Circumvallate papillae

Large papillae located on the posterior tongue containing many taste buds.

Foliate papillae

Papillae located on the sides of the tongue that contain taste buds.

Umami

Savory primary taste sensation associated with amino acids such as glutamate.

Auditory tube

Structure connecting the middle ear to the nasopharynx that equalizes air pressure across the tympanic membrane.

Scala vestibuli

Chamber of the cochlea filled with perilymph.

Cochlear duct

Also known as scala media; middle chamber of the cochlea filled with endolymph.

Scala tympani

Lower chamber of the cochlea filled with perilymph.

Organ of Corti

Spiral organ located on the basilar membrane containing hair-cell mechanoreceptors for hearing.

Pitch

Perception determined by sound wave frequency, where higher frequency corresponds to higher pitch.

Loudness

Perception determined by sound wave amplitude/intensity, where greater amplitude corresponds to louder sound.

Utricle

Vestibular structure containing a macula that detects static equilibrium and linear acceleration.

Saccule

Vestibular structure containing a macula that detects static equilibrium and linear acceleration.

Semicircular ducts

Structures containing the crista ampullaris that detect rotational/angular acceleration.

Macula

Sensory receptor found within the utricle and saccule that detects head position relative to gravity and straight-line movement.

Crista ampullaris

Sensory receptor inside the semicircular ducts that responds to angular/rotational acceleration.

Conductive hearing loss

Hearing impairment caused by a problem transmitting sound through the outer or middle ear structures.

Sensorineural hearing loss

Hearing impairment caused by damage to cochlear hair cells, CN VIII, or the neural auditory pathway.