1. Chapter 11 Medical Terminology and Chapter 10 Body Structures: SPECIAL SENSES
Medical terminology chapter 11, pages 308 – 326.
Exercises: 1 – 100.
Body structures chapters 10, pages 172 – 189.
Exercises: Review questions, labeling.
Body structures workbook chapter 10.
Exercises: A, B, D, F, H, K.
Delmar video “The Special Senses”, tape 14.

2. Functions of the Eyes – receive images and transmit to brain receptor organs of sight
Optic: pertaining to eye or sight
Ocular: pertaining to the eye
Extraocular: outside the eyeball
Intraocular: within the eyeball

3. Structures of the Eye ADNEXA – accessory structures Orbit Eye Muscles
Eyelids
Eyelashes
Conjunctiva
Lacrimal Apparatus
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4. What structure contains and protects the eyeball and its associated muscles, blood vessels, and nerves
ORBIT
Frontal
Sphenoid
Ethmoid
Maxilla
Zygoma
Lacrimal
Palatine
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5. Muscles of the Eye 6 Major muscles attached to each eye
Superior/Inferior Rectus
Superior/Inferior Oblique
Lateral/Medial Rectus
Binocular means both eyes working together.

6. Eyelids: protect the eyeball from foreign matter, excessive light, and impact
Canthus: angle where upper/lower eyelids meet
Inner Canthus
Outer Canthus
Conjunctiva:
lines the underside of each eyelid and provides protective covering over exposed surface of eyeball

7. The Lacrimal Apparatus – structures that produce, store, and remove tears
Lacrimal Glands: secrete lacrimal fluid to maintain moisture on the anterior surface of the eyeball
Lacrimal Canaliculi: ducts at the inner canthus of each eye – collect tears and drain them into the lacrimal sac
Lacrimal sac: an enlargement of the upper portion of the lacrimal duct
Lacrimal duct: passageway that drains lacrimal fluid into the nose

8. Eyebrows and Eyelashes
Prevent foreign
matter from reaching the eye
Cilia – small hairs that are
located along the edges
of the eyelids (eyelashes)

9. The Eyeball - globe Made up of 3 layers Sclera Choroid Retina
Interior of eye is divided into anterior/posterior segments
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10. The Sclera – the white of the eye
Outer layer of eye
Maintains shape of the eye and protects the delicate inner layers of tissue
Cornea: transparent anterior portion of the sclera
Provides most of the optical power of the eye

11. The Uveal Tract The vascular layer of eye
Choroid: opaque (light cannot pass through it) middle layer of the eyeball – provides blood supply for entire eye
Iris: colored layer that surrounds pupil – it’s muscles control amount of light entering eye – decrease - muscles contract making opening smaller (visa versa)
Pupil: black circular opening in center of iris – permits light to enter eye
Lens: focuses images on the retina – located behind iris and pupil
Ciliary Body: located within the choroid, set of muscles and ligaments that adjust lens to refine the focus of light rays on the retina
Near-by objects = thicker
Distance objects = thinner

12. The Retina
Nerve layer located between the posterior chamber and the choroid layer at the back of the eye
Contains light sensitive rods (black/white receptors) and cones (color receptors)
Receive images and convert them into nerve impulses
Optic disk: (blind spot) – contains no rods/cones – nerve endings of retina gather to form optic nerve which transmits nerve impulses from the retina to the brain

14. The Anterior Segment – front 1/3 of eye
Divided into anterior
and posterior chambers
Anterior chamber
behind the cornea in
front of the iris
Posterior chamber
Between the back of the iris and
the front of the lens
These chambers filled with aqueus humor (fluid)
Nourishes intraocular structures
Constantly filtered and drained which regulates intraocular pressure (IOP = btwn 12 & 21 mm Hg)

15. The Posterior Segment – posterior 2/3 of eye
Aids in maintaining the
shape of the eye
Contains vitreous
humor
Lined with retina and
it’s related structures

17. Normal Action of the Eye
Accommodation: the eyes make adjustments for seeing at various distances
Includes constriction or dilation of the pupil, movement of the eye, and changes in the shape of the lens
Convergence: simultaneous inward movement of both eyes – in an effort to maintain single binocular vision as an object comes nearer
Visual Acuity: the ability to distinguish object details and shape at a distance
Normal vision = 20/20
Snellen Chart: used to measure visual acuity

18. Glaucoma
Glaucoma is the increase of the IOP
(intra-ocular pressure)

19. Macular Degeneration Loss of central vision over a period of time but,
not total blindness

20. Pathology of the Eyes - EYELIDS
Blepharoptosis (A)
Ectropion (B)
Entropion (C)
Hordeolum: (D) A B D C

21. Functions of the Ears
Receive sound impulses and transmit them to the brain
Inner also helps maintain balance
Auditory: pertaining to the sense of hearing
Acoustic: relating to sound or hearing

22. Structures of the Ear The Outer Ear The Middle Ear The Inner Ear
The Auditory Ossicles
The Eustachian Tubes
The Inner Ear

23. The Outer Ear Pinna: auricle – External portion Catches sound
waves and transmits
them into the
external auditory canal
(EAC)
EAC: transmits sound waves from pinna to middle ear
What is the name for the sticky yellow-brown substance that functions to prevent bacteria and dust from entering the middle ear??
CERUMEN (earwax)

24. The Middle Ear Tympanic Membrane (eardrum)
Transmits sound by vibrating
Surrounded by hollow air spaces – mastoid cells (which can easily become involved in a middle ear infection)

25. The Auditory Ossicles Malleus: hammer Incus: anvil Stapes: stirrup
3 small bones in the middle ear
Transmit sound waves from the eardrum to the inner ear by vibration
Named for their shape
Malleus: hammer
Incus: anvil
Stapes: stirrup

26. malleus
stapes
incus

27. The Inner Ear- labyrinth
Contains sensory receptors for
hearing and balance
Cochlea: spiral shaped passage that leads
from the oval window
Cochlear duct: filled with fluid that vibrates when sound waves strike it
Organ of Corti: receptor site
that receives vibrations and
relays them to the auditory
nerve fibers that transmit
them to the auditory center
of the cerebral cortex, where
they are interpreted and heard
Semicircular canals: helps maintain
equilibrium

28. Normal Action of the Ears
Air conduction: sound waves enter the ear through the pinna, travel down the auditory canal, and strike the TM between the outer and middle ear
Bone conduction: as the eardrum vibrates, it moves the auditory ossicles and these conduct sound waves through the middle ear
Sensorineural conduction: sound vibrations reach the inner ear via the oval window where the structures of the inner ear receive the sound waves and relay them to the brain

29. Pathology of the Ears Outer Ear Middle Ear Inner Ear Hearing Loss
Otalgia: earache
Otitis: inflammation of the ear
Otomycosis: swimmer’s ear
Middle Ear
Eustachitis: inflammation of the eustachian tube
Mastoiditis
Otosclerosis: ankylosing of the bones of the middle ear = hearing loss
Otitis Media
Inner Ear
Meniere’s syndrome: vertigo, fluctuating hearing loss, tinnitus (ringing or buzzing in the ears)
Hearing Loss
Deafness
Noise-Induced hearing loss

30. Diagnostic Procedures of the Ears
Audiometry: use of audiometer to measure hearing
Speech audiometry: measures the threshold of speech reception and speech discrimination
Monaural: testing involving one ear
Binaural: testing involving both ears

31. audiometry
Both ears - AU
Right ear - AD
Left ear - AS

32. Treatment Procedures of the Ears
Outer Ear
Otoplasty: surgical repair of the pinna of the ear
Middle Ear
Mastoidectomy
Tympanocentesis
Tympanostomy tubes
Inner Ear
Fenestration
Labyrinthectomy
Labyrinthotomy

33. Mastoidectomy
otoplasty
labyrinthectomy
tympanostomy