Outer Ear

The pinna

• Varies in size and shape from person to person.

• Gathers sound waves from the environment

• Is made of cartilage

• Emphasizes high frequencies

• Helps in localization of sounds

External Auditory Canal (EAC)

• A tube beginning at the concha and extending inward for approximately an inch in adults.

• Wax or cerumen comes from sebaceous

glands in the outer 1/3

• has two bends and is shaped like an “s”

The Tympanic Membrane (TM)

• at the end of the ear canal

• protected from trauma

• constant temperature and humidity

• boundary between the outer and middle ear

• concave disk shaped membrane consisting of 3 layers

• very think and a very efficient vibrating surface

• very rich in blood supply

Otoscopy

• Performed with an otoscope

• Pull up and back on the pinna for adults

• Pull downward and backward on the pinna for children.

• Purpose

• Inspect the external auditory canal

• Note debris, foreign objects, cerumen, growths, color

• Evaluate the tympanic membrane

• Note the color, translucency, position (bulging, retracted, neutral)

• Identify landmarks

Cerumen

• Outer 1/3 of earcanal

• Acts as a natural barrier from dirt and bacteria

• Insect repellent

• Keeps ear moisturized

• Colors

• Light brown, Orange, Yellow are normal

• Dark Brown or black – Older wax with dirt

• Texture

• Soft

• Hard