Transcript Ch 10 BS and CH 11 MT

Chapter 11 Medical Terminology
and
Chapter 10 Body Structures:
SPECIAL SENSES
Functions of the Eyes – receive
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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
Structures of the Eye
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ADNEXA – accessory
structures
 Orbit
 Eye Muscles
 Eyelids
 Eyelashes
 Conjunctiva
 Lacrimal Apparatus
www.ipo.tue.nl/.../seminar-2%20human/ sld015.htm
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What structure contains and
protects the eyeball and its
associated muscles, blood
vessels, and nerves
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ORBIT
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www.lau-verlag.de/anatom/ skeletal-system.htm
Frontal
Sphenoid
Ethmoid
Maxilla
Zygoma
Lacrimal
Palatine
Muscles of the Eye
6 Major muscles
attached to each
eye
 Superior/Inferior
Rectus
 Superior/Inferior
Oblique
 Lateral/Medial
Rectus
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Binocular means both eyes working together.
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Eyelids: protect the
eyeball from foreign
matter, excessive
light, and impact
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Canthus: angle where
upper/lower eyelids
meet
 Inner Canthus
 Outer Canthus
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Conjunctiva:
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lines the underside
of each eyelid and
provides protective
covering over
exposed surface of
eyeball
The Lacrimal Apparatus – structures that
produce, store, and remove tears
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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
Eyebrows and Eyelashes
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Prevent foreign
matter from reaching the eye
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Cilia – small hairs that are
located along the edges
of the eyelids (eyelashes)
The Eyeball globe
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www.optelec.com/ lv_ref.php
Made up of 3 layers
 Sclera
 Choroid
 Retina
Interior of eye is
divided into
anterior/posterior
segments
The Sclera – the white of the eye
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Outer layer of eye
Maintains shape of
the eye and protects
the delicate inner
layers of tissue
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Cornea: transparent
anterior portion of the
sclera
Provides most of the
optical power of the
eye
The Uveal Tract
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The vascular layer of eye
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Choroid: opaque (light
cannot pass through it) middle
layer of the eyeball – provides
blood supply for entire eye
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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
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Ciliary Body: located
within the choroid, set of
muscles and ligaments
that adjust lens to refine
the focus of light rays on
the retina
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Near-by objects = thicker
Distance objects = thinner
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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)
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Receive images and
convert them into nerve
impulses
The Retina
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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
The Anterior Segment –
front 1/3 of eye
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Divided into anterior
and posterior chambers
Anterior chamber
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Posterior chamber
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behind the cornea in
front of the iris
Between the back of the iris and
the front of the lens
These chambers filled with aqueus humor (fluid)
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Nourishes intraocular structures
Constantly filtered and drained which regulates intraocular
pressure (IOP = btwn 12 & 21 mm Hg)
The Posterior Segment –
posterior 2/3 of eye
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Aids in maintaining the
shape of the eye
Contains vitreous
humor
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Lined with retina and
it’s related structures
Normal Action of the Eye
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Accommodation: the eyes make adjustments for
seeing at various distances
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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
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Normal vision = 20/20
Snellen Chart: used to measure visual acuity
Glaucoma
Glaucoma is the increase of the IOP
(intra-ocular pressure)
Macular Degeneration
Loss of central vision over a period of time but,
not total blindness
Pathology of the Eyes EYELIDS
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Blepharoptosis (A)
Ectropion (C)
Entropion (B)
Hordeolum: (D)
A
C
B
D
Functions of the Ears
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Receive sound
impulses and transmit
them to the brain
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Inner also helps
maintain balance
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Auditory: pertaining
to the sense of
hearing
Acoustic: relating to
sound or hearing
Structures of the Ear
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The Outer Ear
The Middle Ear
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The Auditory
Ossicles
The Eustachian
Tubes
The Inner Ear
The Outer Ear
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Pinna: auricle –
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External portion
 Catches sound
waves and transmits
them into the
external auditory canal
(EAC)
EAC: transmits sound waves from pinna to middle ear
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What is the name for the sticky yellow-brown substance
that functions to prevent bacteria and dust from entering
the middle ear??
CERUMEN (earwax)
The Middle Ear
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Tympanic Membrane (eardrum)
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Transmits sound by vibrating
Surrounded by hollow air spaces – mastoid cells
(which can easily become involved in a middle
ear infection)
The Auditory Ossicles
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3 small bones in the
middle ear
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Transmit sound waves from
the eardrum to the inner
ear by vibration
Named for their shape
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Malleus: hammer
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Incus: anvil
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Stapes: stirrup
malleus
stapes
incus
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The Inner Ear-
Contains sensory receptors for
hearing and balance
labyrinth
 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
Normal Action of the Ears
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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
Pathology of the Ears
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Outer Ear
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Middle Ear
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Eustachitis: inflammation of the eustachian tube
Mastoiditis
Otosclerosis: ankylosing of the bones of the middle ear =
hearing loss
Otitis Media
Inner Ear
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Otalgia: earache
Otitis: inflammation of the ear
Otomycosis: swimmer’s ear
Meniere’s syndrome: vertigo, fluctuating hearing loss, tinnitus
(ringing or buzzing in the ears)
Hearing Loss
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Deafness
Noise-Induced hearing loss
Diagnostic Procedures of the Ears
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Audiometry: use of audiometer to
measure hearing
Speech audiometry: measures the
threshold of speech reception and speech
discrimination
Monaural: testing involving one ear
Binuaral: testing involving both ears
audiometry
Both ears - AU
Right ear - AD
Left ear - AS
Treatment Procedures of the Ears
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Outer Ear
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Middle Ear
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Otoplasty: surgical repair of the pinna of the
ear
Mastoidectomy
Tympanocentesis
Tympanostomy tubes
Inner Ear
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Fenestration
Labyrinthectomy
Labyrinthotomy
otoplasty
tympanostomy
Mastoidectomy
labyrinthectomy