Otitis Externa

Causes

trauma to the canal

humidity

dry skin

foreign bodies

lack of cerumen

eczema

dermatitis

Otitis Externa

Signs and Symptoms

pain

pruritis (itching)

erythema (redness) of canal

canal drainage

edema (increase in interstitial fluid - swelling)

cervical lymphadenopathy (swollen cervical lymph nodes)

conductive hearing loss

Otitis Externa

Treatment

dry canal

antibiotic drops

oral antibiotics

antiinflammatory meds

Acute Otitis Media

(AOM)

Causes

Usually follows URI (viral)

allergies

Eustachan tubes blocked with secretions, fluid accumulates

Acute Otitis Media

(AOM)

Signs and symptoms

otalgia

hearing loss

vertigo

many non specific symptoms

TM bulging

inflamed

erythermatous (causing redness)

distorted bony landmarks

+/- perforation

Acute Otitis Media

(AOM)

Treatment

antibiotics (especially <6 months)

vs.

observation

pain control

tympanostomy tubes for chronic effusion

Cochlea

Semicircular Canals

Vestibule

Hearing

Houses organ of corti

pressure waves (sound) --> liquid waves (mechanical energy) --> auditory nerve (electrical energy) --> brain

Equalibrium

superior

lateral

posterior

sense angular and rotational movements of the head

Equalibrium

Utricle and Saccule

sense acceleration and deceleration of the head

[image]

The Organ of Corti

Part of CN VIII

Sound waves vibrate basilar membrane

Shearing force b/w basilar membrane and tectoarial membrane cause steriocila to bend

Auditory nerve fibers pass signal to auditory cortex in the brain

Myopia

image focused IN FRONT of the retina

eyball axis is too LONG or refractive power is too STRONG

*most common refractive error in children

DISTANT objects appear out of focus

NEARSIGHTEDNESS

[image]

[image]

Myopia

Treatment of Myopia with Concave Lens

Hyperopia

image focused BEHIND the retina

eyeball axis is too SHORT or refractive power is too WEAK

CLOSE OBJECTS appear out of focus

FARSIGHTEDNESS

[image]

[image]

Hyperopia

Hyperopia treated with Convex Lens

Astigmatism

Cause

Symptoms

Caused by abnormal corneal curvature

Objects at ALL DISTANCES appear blurred

Light rays focus at different areas

May be accompanied by myopia or hyperopia

[image]

[image]

Presbyopia

What is it?

When does it occur?

What happens?

Lens loses its FLEXABILITY

can no longer vary focus

AGE 40 - 50

Difficult to focus on near objects

Corrective lenses required

Retina Histology

LAYERS

The sense of smell is activated by substances carried by airborne molecules into the nasal cavities, where the substances activate highly specialized receptors for smell, located in the olfactory epithelium. From there messages are carried directly to the olfactory bulb in the brain, where they are sent to the brain’s temporal lobe, resulting in our awareness of smells.

[image]

Taste buds- most on the POSTERIOR PORTION of the tongue, contain gustatory cells (live 7-10 days)

Nerve impulses from gustatory cells are conducted via CNVII (facial- anterior 2/3) and CNIX (glossopharyngeal- posterior 1/3) to the brain

Pain

Nociception

What is it?!?

Physiological Pain

The non concious perception of near-damage or damage to tissue

Pain

How is it classified?

From 1 - 3 Senses depending on the classification method

Cutaneous (skin)

Somatic (joints and bones)

Visceral (body organs)