Lauren Cosby

Pressure Equalizing Tube They are small tubes surgically

placed in a child’s eardrum to assist in drainage of trapped fluid and to equalize pressure between the middle ear cavity and the atmosphere.

The two most common reasons why you would need tubes are because of recurrent ear infections or if fluid has built up in your ears causing hearing loss. Both of these problems are most

common between the ages of 6 months and 3 years, although older children sometimes have these problems too.

(cont) During an ear infection, fluid builds

up behind the eardrum in a place called the middle ear space. Normally, when the ear infection

has run its course the fluid drains out of the middle ear into the back of the nose through the body’s natural drainage tube called the Eustachian tube

Sometimes this fluid doesn’t go away because the Eustachian tube remains swollen and can’t open. Fluid trapped behind the eardrum causes a hearing loss because it prevents the eardrum from vibrating normally.

Ear tubes are put in by an ears, nose, and throat surgeon. Using a microscope, a small incision is made in the eardrum. The tube is then placed through this hole. Since the tubes are very small, this

is a delicate operation. Because children cannot hold still for this procedure it is performed in the operating room under general anesthesia.

Eye, Ear, Nose, and Throat

The human eye is an organ which reacts to light for several purposes and allows vision. The human eye can

distinguish about 10 million colors

The ears are responsible for the ability to hear as well as keeping the body’s balance, better known as equilibrium

The visible part of the human nose is the protruding part of the face that bears the nostrils. The is responsible

for smelling. Hairs inside the nose prevent large particles from entering the lungs.

The throat is a ring-like muscular tube that acts as the passageway for air, food, and liquid. The throat also helps in forming speech

Bone Conduction Bone conduction is the

conduction of sound to the inner ear through the bones of the skull.

Bone conduction is the reason why a person's voice sounds different to him/her when it is recorded and played back. Because the skull conducts

lower frequencies better than air, people perceive their own voices to be lower and deeper than others do.

Both Ears The ear is responsible for two main

senses; hearing and euilibrium, our sense of balance Hearing and sensory information

is carried to the brain by cranial nerve VII. This nerve is divided into two major branches The cochlear nerve and the vestibular

nerve

The ear is further subdivided into three areas The external ear The middle ear The inner ear

Although the ear is the vertebrate sense organ that recognizes sound, it is the brain and central nervous system that "hears". The ear changes sound pressure

waves from the outside world into a signal of nerve impulses sent to the brain.

The outer part of the ear collects sound. That sound pressure is amplified through the middle portion of the ear and passed from the medium of air into a liquid medium.

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Otitis Media Seen frequently in children ;

commonly referred to as middle ear infection. Often preceded by an upper respiratory infection during which pathogens move from the pharynx to the middle ear via the eustachian tube. Fluid accumulates in the

middle ear cavity. The fluid may be watery or full of pus

Otitis media has many degrees of severity, and various names are used to describe each. Acute, Serous, and chronic

suppurative

Otitis media is most commonly caused by infection with viral, bacterial, or fungal pathogens. Viruses such as RSV

(respiratory syncytial virus) and those that cause the common cold may also result in otitis media by damaging the normal defenses of the epithelial cells in the upper respiratory tract.

Emmetropia Emmetropia is a state in

which the eye is relaxed and focused on an object more than 20 feet away.

It’s basically the state of normal vision because the eye is automatically focused on things in the distance unless a conscious effort is made to focus elsewhere.

An object at infinity is in sharp focus with theeye lens in a neutral or relaxed state. This condition of the normal eye is achieved when the refractive power of the cornea and the axial length of the eye balance out, which focuses rays exactly on the retina resulting in perfect vision. An eye in a state of

emmetropia requires no correction.

Exotropia The outward turning of

the eye; also called wall-eyed. (muscle weakness of the eye)

There are six muscles that

control eye

movement, four that move

it up and down and two

that move it side to side.

All these muscles must be

coordinated and working

properly in order for the

brain to see a single image.

(cont) Although glasses and/or

patching therapy,

exercises, or prisms may

reduce or help control the

outward-turning eye in

some children, surgery is often required

One study has found that children with exotropia are three times more likely to develop a psychiatric disorder in comparison with the general population

Left Eye Also referred to as the

OS (oculus sinister) is an organ of sight

Extraocular Movement The actions of the extraocular

muscles depend on the position of the eye at the time of muscle contraction

Intermediate directions are controlled by simultaneous actions of multiple muscles. When one shifts the gaze horizontally, one eye will move laterally (toward the side) and the other will move medially (toward the midline). This may be neurally coordinated by the central nervous system, to make the eyes move together and almost involuntarily. This is a key factor in the study of squint, namely, the inability of the eyes to be directed to one point.

There are two main kinds of movement: conjugate movement (the eyes move in the same direction) and disjunctive (opposite directions).

Conjugate is typical when shifting gaze right or left, the latter is convergence of the two eyes on a near object. Disjunction can be performed voluntarily, but is usually triggered by the nearness of the target object.

A "see-saw" movement, namely, one eye looking up and the other down, is possible, but not voluntarily; this effect is brought on by putting a prism in front of one eye, so the relevant image is apparently displaced.

Visual Acuity Visual acuity is

acuteness or clearness

of vision, which is

dependent on the

sharpness of the retinal

focus within the eye and

the sensitivity of the

interpretative faculty of the brain.

The visual acuity test is used to determine the smallest letters a person can read on a standardized chart (Snellen chart) or a card held 14 - 20 feet away.

Numbers or pictures are

used for people who cannot read, especially children.

(cont) The visual acuity test is a

routine part of an eye examination or general physical examination, particularly if there is a change in vision or a problem with vision.

In children, the test is performed to screen for vision problems. Vision problems in young children can often be corrected or improved. Undetected or untreated problems may lead to permanent vision damage.

Example of a typical Snellenchart