External Auditory Meatus & Tympanic Membrane

External Auditory Meatus

Ear canal surrounded by cartilage and bone

Cartilage

Connective tissue that cushions the ear canal

Bone

Supports the meatus and delicate middle ear structure

Skin

Lining the pinna and ear canal, thin near the eardrum

Ceruminous Glands

Produce earwax to protect the ear canal

Sebaceous Glands

Secrete sebum to moisturize and protect the skin

Self Cleaning Mechanism

Skin grows outwards, pushing out harmful material

Ear Wax

Sticky substance that traps matter to prevent invasion

Sweat

Antibacterial and antifungal, helps protect the skin

Resonance

Ear canal vibrates at a certain frequency

Tympanic Membrane

Seals the middle ear, reflects light from an otoscope

Eustachian Tube

Connects the middle ear to the back of the throat

Concave Disk

Shape of the tympanic membrane at an angle of 55 degrees

Cone of Light

Reflected light on the tympanic membrane

Umbo

Most depressed part of the tympanic membrane

Malleus

Ossicle directly behind the tympanic membrane

Pars Flaccida

Small, floppy and loose portion of the tympanic membrane

Pars Tensa

Thicker portion of the tympanic membrane

Annular Ligament

Fibrous tissue and cartilage that holds the tympanic membrane in place

Tympanic Sulcus

Groove in the bone where the annular ligament sits

Epithelial Layer

Layer of the pars tensa continuous with the skin lining the ear canal

Fibrous Layer

Tough connective tissue providing strength and tautness in the pars tensa

Mucous Membrane Layer

Layer of the pars tensa that produces moisture