Chapter 5 Special Senses

Visual System

Comprises the eyes and optic nerves, which transmit information to the occipital lobe.

Auditory System

Consists of the ears and auditory nerves, which send signals to the temporal lobe.

Somatosensory System

Made of specialized receptor cells, primarily in the skin, that respond to tactile stimuli and send info to the parietal lobe's sensory cortex.

Olfactory System

Begins with nerves in the nasal passages that analyze scents and pass information to the amygdala and hippocampus.

Gustatory System

Starts with taste buds on the tongue, sending input along the facial nerve to the primary gustatory cortex.

Ambly(o)-

Dim, dullness

Blephar/o-

Eyelid

Conjunctiv/o-

Conjunctiva

Cor/o-

Pupil

Cycl/o-

Ciliary body

Dacry/o-

Tear

Glauc/o-

Gray

Irid/o-

Iris

Lacrim/o-

Tear

Mi/o-

Smaller

Ocul/o-

Eye

Ophthalm/o-

Eye

Palpebr/o-

Eyelid

Papill/o-

Optic nerve

Phac/o-

Lens of the eye

Presby/o-

Old age

Retin/o-

Retina

Scler/o-

Sclera

Scot/o-

Darkness

Uve/o-

Uvea

Vitre/o-

Glassy

-opia

Vision

-tropia

To turn

Amblyopia

Lazy eye, causing vision dullness

Ametropia

Eye refractive power defect

Aphakia

Absence of lens of the eye

Astigmatism

Abnormal curve of the cornea, preventing light from focusing on the retina and causing out-of-focus vision

Blepharitis

Inflammation of the edges of the eyelid

Cataract

Opacity in or on the lens

Chalazion

Granuloma around a sebaceous gland on the eyelid

Conjunctivitis

Inflammation of the mucous membrane covering the eye and inside of eyelids

Cycloplegia

Paralysis of the ciliary muscle

Dacryocystitis

Inflammation and obstruction of the nasolacrimal duct

Dacryostenosis

Narrowing of the lacrimal duct

Diplopia

Double vision

Ectropian

Eyelid eversion (turning outward)

Entropian

Eyelid inversion (turning inward)

Enucleation

Removal of an organ from a body cavity

Episclera

Connective covering of the sclera

Exenteration

Radical excision; removal of an organ in one piece

Exophthalmos

Anterior protrusion of the eyeball out of the orbit

Glaucoma

Increased intraocular pressure

Hordeolum

Infection of a sebaceous gland on the eyelid; stye

Hyperopia

Farsightedness

Keratomalacia

Softening of the cornea due to vitamin A deficiency

Keratitis

Inflammation of the cornea

Myopia

Nearsightedness

Nystagmus

Rapid, involuntary eye movements, usually caused by a brain tumor, inner ear condition, or adverse drug reaction

Ophthalmologist

Physician who specializes in the diagnosis and treatment of diseases of the eye

Ophthalmoscope

Instrument used to examine the interior portion of the eye

Papilledema

Swelling of the optic disk

Presbyopia

Farsightedness due to aging and progressive disease

Ptosis

Drooping of the upper eyelid

Retinopathy

Non-inflammatory, degenerative disease of the retina

Strabismus

Extraocular muscle deviation causing an unequal visual axis (cross-eyed)

Tarsorrhaphy

Suturing of eyelids together

Tonometer

Instrument measuring intraocular pressure

Trichiasis

Ingrown eyelashes that rub against the cornea, causing irritation

Uveal

Vascular tissue of the choroid, ciliary body, and iris

Xanthelasma

Lipid disorder presenting as a yellow plaque on the eyelid

Conjunctiva

Clear membrane covering the front of the eye and the inside surface of the eyelids

Sclera

White, opaque, protective outer layer that provides an attachment surface for extrinsic muscles

Cornea

Avascular clear area of the sclera with touch/pain receptors that allows light to pass into the anterior chamber; absorbs oxygen from the air

Anterior Chamber

The space filled with aqueous humor located between the cornea and the lens

Choroid

Vascular middle layer of the eye providing blood and oxygen supply

Pupil

Opening that allows light to enter the inner eye from the anterior chamber; dilates under sympathetic control

Iris

Colored ring of muscles that contracts or dilates to regulate the amount of light entering the eye

Lens

Biconvex crystalline disc that focuses light entering through the pupil onto the retina

Supersensory Ligaments

Ligaments connecting the lens to ciliary muscles to alter lens shape for focusing

Posterior Chamber

Space behind the lens filled with thick, gel-like vitreous humor to maintain eye shape

Retina

Innermost layer at the back of the eye containing rods (low light/peripheral) and cones (bright light/color)

Optic Disc

The 'blind spot' of the eye where the optic nerve meets the retina; lacks rods and cones

Open-Angle Glaucoma

Most common chronic form where the trabecular meshwork fails to drain aqueous humor adequately, leading to gradual tunnel vision

Closed-Angle Glaucoma

Acute, painful form where the iris is squeezed against the cornea, blocking drainage; causes headaches, eye pain, and visual halos

Pilocarpine

Miotic class drug that contracts ciliary muscles to open the anterior chamber angle and increase fluid outflow

Prostaglandins

Medications (e.g., travoprost, latanoprost) that encourage aqueous fluid drainage to lower intraocular pressure

Beta Blockers (Ophthalmic)

Medications (e.g., betaxolol, timolol) that reduce the total production of aqueous humor

Phacoemulsification

Common cataract surgery using high-frequency ultrasonic vibrations to break up the lens before suctioning it out

Extracapsular vs. Intracapsular Surgery

Extracapsular removes the lens nucleus in one piece leaving the posterior capsule; Intracapsular removes the entire lens and capsule

Wet vs. Dry Macular Degeneration

Wet involves neovascularization and leaking blood/fluid treated with photocoagulation; Dry involves gradual atrophy with no current treatment

Retinal Detachment Interventions

Treated via photocoagulation (laser scar creation), pneumatic retinopexy (gas bubble + freezing), or scleral buckle (silicone band stitching)

Audit/o- or Audi/o-

Hearing

Aur/o- or Auricul/o-

Ear

Cochle/o-

Cochlea

Myring/o- or Tympan/o-

Tympanic membrane (eardrum)

Ossicul/o-

Ossicle (small bone)

Ot/o-

Ear

Salping/o-

Eustachian tube

Staped/o-

Stapes (stirrup bone)

Vestibul/o-

Vestibule

-acusis

Hearing

-meter

Instrument to measure

-otia

Ear condition

Audiology

The study of hearing disorders

Apicectomy

Excision of a portion of the temporal bone