Term
| Paralysis of single eye muscle |
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Definition
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Term
| Direct and Consensual light reflex |
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Definition
constriction of ipsilateral and contralateral
pupil when a light is shone into one eye. It shows the function of CN III and also the
optic pathway. These reflexes may be lost in head trauma etc.
Pupillary dilation due to CNIII palsy may be due to tumors, aneurysms… |
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Term
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Definition
progressive degeneration and opacity
of the lens which leads to impaired vision and
blindness. |
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Term
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Definition
retinal ischemia and blindness due to
impaired drainage of the aqueous humor from the
Schlemm’s canal. Leads to increased intraocular
pressure and increased retinal blood flow |
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Term
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Definition
when the optic disk bulges out due
to increased intracranial pressure. |
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Term
| Clinical examination of the ear |
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Definition
Clinical examination of the Meatus and the membrane is done by means of
an Otoscope (Auriscope) which is supplied by shining light into a hollow
speculum. The cone of light seen, has its apex at Umbo and expands
downward and forward. This cone, changes in disease. |
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Term
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Definition
is an incision through the tympanic membrane (its anteroinferior quadrant) and
insertion of a tube for drainage of secretions and pus in severe cases of
otitis media and/or chronic otitis media. |
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Term
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Definition
causes loss of
function of Stapedius muscle and loss of
dampening the sound stimuli, leading to
Hyperacusis (an increased sensitivity to sound). |
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Term
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Definition
**The bony roof and floor of the tympanic cavity may be very thin, so that infection
of the middle ear may penetrate through roof and from mastoid cells to the meninges,
to the brain (meningitis and cerebral abscess in the temporal lobe) and through the
floor into internal Jugular vein (jugular thrombosis); this is extremely important in
children since the bony walls are still much thinner than in adults.
**Auditory (eustachian) tube opens into the anterior wall of the tympanic cavity. It
connects the middle ear to the nasopharynx and helps to equalize the pressure
in the cavity. A pressure difference of 100-150 mmHg can rupture the tympanic
membrane. Infection from nasopharynx can get into the
middle ear through the auditory tubes.
**Otosclerosis at the edges of the oval window disturbs the movement of Stapes
and is the most common cause of deafness in adults. |
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