EAR Anat and Physiol.

8/2/2019 EAR Anat and Physiol.

1/22

THE EAR: PRACTICALANATOMY & PHYSIOLOGY:

J.W. Loock, Dept. of ORL

Faculty of Health Sciences

US/TBH


2/22

Some questions you should be able to answer

by the end of this lecture:

Where (anatomically) may/may you not wear an earring?

Why should you throw you earbuds away?

What makes it possible to hear whispered

sweet nothings?

Why should airlines give you gum to chew on descent?

Why does syringing an old ladys ear with cold tapwater

make her dizzy?

How does the ear differentiate between low & high-pitched

sounds?

Why do your ears ring after a rave party?


3/22

Ear: The 3 Parts:

External Ear: Pinna

External Auditory Meatus

Drum (Tympanic Membrane)


4/22


5/22

Ear: The 3 Parts:

Inner Ear: The Labyrinth

Cochlea

Vestibule: Utricle

Saccule

Semicircular Canals

Vestibulocochlear Nerve --> CNS


6/22

External Ear:

Tissues: Function: Skin incl Desquamation, migration

Wax Protection, migration

Hairs protection, expulsion

Cartilage Perichondrium

Bone

Eardrum Seals off Middle Ear

Pinna

External Auditory

Meatus

Drum (TympanicMembrane)


7/22

Middle Ear Cleft:

Middle Ear itself

Eustachian Tube

Mastoid Air Cell System


8/22

Middle ear Cleft: parts:

Middle ear per se: Mesotympanum

Epitympanum (attic)

Hypotympanum

Eustachian Tube

Mastoid:

Antrum Aditus

Air cells

Left M.E.Cleft


9/22

Middle ear anatomy: contents:

Eardrum

Ossicles: malleus

incus

stapes

Oval Window

Round Window

Facial Nerve


10/22

Middle ear Physiology:

Aeration:

Eustachian tube

Mastoid air cell reservoir

Mucosa

Sound amplification

TM

Ossicles


11/22


Aeration:

Eustachian tube


Mucosa

Sound amplification

TM

Ossicles


12/22


Aeration:

Eustachian tube


Mucosa

Sound amplification

TM

Ossicles


13/22

Ear: The 3 Parts:

Inner Ear: The Labyrinth

Cochlea

Vestibule: Utricle

Saccule

Semicircular Canals



14/22

THE INNER EAR:

Cochlea

Vestibule: Utricle

Saccule

Semicircular Canals


Th I E C hl


15/22

The Inner Ear: Cochlea:

Twisted tube:

Basal turn to apex

3 Compartments:

Scala tympani

Scala media

Scala vestibuli

Basilar membrane &

hair cells


16/22

The Inner Ear: Cochlea: Function:

HEARING:Sound wave travels up

Basilar Membrane

Pitch (frequency)

determines place of max.

displacementHair cells of Organ of Corti

on Basilar Membrane

transform movement intoelectrical impulses =>

Cochlear Nerve=>

Cerebral Cortex


17/22

INNER EAR: PHYSIOLOGY:

Cochlea Vestibular labyrinth

Saccule + Utricle + Semicircular canals

Hearing Static position + linear Angular accelerationacceleration

Maculae: Hair cells + Ampullary crista: Hairstatoconial membrane cells + cupulae

Vestibulocochlear nerve (VCN)

.

.

EQUILIBRIUM


18/22

EQUILIBRIUM:ANATOMY & PHYSIOLOGY OF VESTIBULAR

APPARATUS Bony Labyrinth contains membranous

(Outer) Perilymph ~ Extracellular Fluid

(Inner) Endolymph ~ Intracellular Fluid (K,Na)

EQUILIBRIUM:


19/22

+++


APPARATUSMACULA (of utricle & saccule)

Hair cells

Statoconial membrane (CaCo3 crystals in mucopolysaccharide bed)

Static position & linear acceleration

EQUILIBRIUM:


20/22


APPARATUSMACULA (of utricle & saccule)

Hair cells

Statoconial membrane (CaCo3 crystals in mucopolysaccharide bed) Static position & linear acceleration

EQUILIBRIUM:


21/22


APPARATUSAMPULLARY CRISTA:

Dilated ampulla at end of semicircular canal

Hair cells Cupula

Angular acceleration

EQUILIBRIUM:


22/22


APPARATUSSEMICIRCULAR CANALS:

Orientated in 3 different spacial planes

at +/- right angles able to track exact direction of acceleration

EAR Anat and Physiol.

Documents

Transcript of EAR Anat and Physiol.