Download Membranous labyrinth

SENSE ORGANS
THE AUDIOVESTIBULAR ORGAN
1.
2.
3.
4.
5.
6.
Taste buds
Audiovestibular analizator
Audiovestibular organ
External ear
Middle ear
Internal ear:
a) bony labyrinth;
b) membranous labyrinth
7. Hair cells
8. Audiovestibular organ
histophysiology
ANALIZATOR
sense organ + nerve +
cortex (field)
Sense organs
Primary sensory
Secondary
sensory
Sensory
endings
1. Eye
2. Smell organ
Ear
Taste buds
1. Receptor of pain
2. Paccinian body
3. Bulb of Krause…
(receptors)
Organ of taste
(taste buds)
(50%) in foliate papillae
(50%) in circumvallate papillae
(few in lips, epiglottis, vocal folds)
Taste buds
(2000, calliculi gustatoriae)
Fundamental taste sensations
sweet
bitter
acid
salty
glutamate
Structure of taste bud
Taste pit
Taste pore
Bud like aggregation of 40-60 cells
1. Sensoepithelial cells
2. Supporting cells
3. Basal cells
AUDIOVESTIBULAR
ORGAN (EAR)
Functions –hearing and
balance
External ear
Middle ear
Internal
External ear (pinna, external
auditory tube, tympanic
membrane)
Receives sound waves
Middle ear (tympanic cavity,
auditory ossicles, auditory tube)
Transforms sound waves into
mechanical oscillation of ossicles
Internal ear (vestibule,
3semicircular canals, cochlea)
Converts mechanical oscillations
in nerve impulses
External ear
Pinna (auricle) funnel like plate
of elastic cartilage + skin
External auditory tube – 2,5-3 cm
Cartilage and bony portion
Lined with skin
Has sebaceous and ceruminous
glands (apocrine sweat glands
producing ear wax- cerumen-for
protection)
Tympanic membrane
Tympanic membrane
Functions
1. Separates tympanic cavity of
middle ear and external
auditory tube;
2. Transmits sound waves to
ossicles (malleus)
Structure
1. Skin
2. Fibrous connective tissue
3. Simple squamous epithelium
of mucosa
Middle ear
Tympanic cavity – irregular airfilled space in temporal bone,
lined with mucosa
Auditory ossicles – malleus,
incus and stapes – transmit
mechanical oscillations to oval
window of inner ear
Auditory tube – Eustachian
tube, 4 cm, extends from
tympanic cavity to
nasopharinx, lined with
mucosa
INTERNAL EAR
vestibule+3 semicircular canals
+cochlea
Bony labyrinth
Membranous labyrinth
Otolith
membrane
Hair cells
Macula
Maculae
Organ of Corti
Tectorial membrane
Cristae ampullaris
Cristae ampullaris
Cupula
Hair cells
Hair cells
Organ of Corti
Crista ampullaris
Perilymph (bony labyrinth)
1. Like extracellular fluid
2. Low protein content
3. Is connected with subdural
space by perilymphatic duct
Endolymph (membranous
labyrinth)
1. Low protein content
2. Low Na content
3. High K content
4. Is connected with endolymphatic sac by endolymphatic duct
Membranous labyrinth
(cochlear duct)
Maculae
of utricle
Maculae
of saccule
Cochlear duct
Ampullary
crests
Maculae
Cells of
maculae
Sensory cells:
cylindrical and
piriform
Have 60-80
stereocilia
(40 mkm) and
1 kinocilium
Supporting
cells
Crista ampullaris
Cells of ampullary crest
Cochlea axial section
Helicotrema
Modiolus
Scala vestibuli
Spiral
ganglion
Cochlear duct
Scala tympani
Cohlear nerve
MEMBRANOUS
LABYRINTH
• Cochlear duct - triangular
Membranous labyrinth
(scheme)
Vestibular membrane
Basilar membrane
Stria vascularis
Scala vestibuli
Cochlear duct
Spiral ligament
Stria vascularis
Basilar
membrane
Vestibular membrane
Tectorial membrane
Spiral limbus
Spiral tunnel
Spiral bony lamella
Cochlear nerve
Scala tympani
Membranous labyrinth
or cochlear duct
Vestibular membrane –
Reissner’s membrane –
epithelium, BM, epithelium
Basilar membrane – consists of
fibers (collagen) and epithelia
Stria vascularis – lies over spiral
ligament, epithelium contains
capillaries
Corti’s organ
Stria vascularis
Hair cells
Hensen cells
Outer
Basilar
phalangeal cells
membrane
Pillar cells
Corti’s organ
Outer hair cells
Tectorial
membrane
Outer border cells
Spiral tunnel
Outer
Supporting
cells
Inner hair cells
Nerve fibers
Inner border cells
Inner tunnel
Cochlear nerve
Betshar’s
cells
Outer
phalangeal
cells
Inner phalangeal cells
Inner and
outer
Basilar membrane
pillar cells
Corti’s organ
Tunnel (pillar cells)
Outer cells:
A. Supporting 1. Phalangeal
(Deyters)
2. Border (Hensen)
3. Outer supporting (Claudius)
4. Betshar’s cells
B. Hair cells (3-5)
Inner cells
A. Supporting 1. Phalangeal
2. Inner supporting
B. Hair cells (1-2)
Apical portion
of outer phalangeal and
hair cells
1
2
3
4
1. Stereocilia
2. Cuticula
3. Phalangeal processes
4. Hair cells bodies
Phalangeal and hair
cells (scheme)
Stereocilia
Cuticular
lamella
Phalangeal
process
Marginal
network
Outer hair cell
Outer
phalangeal cell
Basilar
membrane
Afferent
and efferent
nerve fibers
Hair cells stereocilia
Excitation
Apical
junctions
Stereocilia
Basal body
Cuticular lamella
Microtubuli
Audiovestibular organ
histophysiology
Subarachnoidal space
Semicircular
canals
Ampulae
Endolymphatic sac
Endolymphatic duct
Perilymphatic duct
Scala vestibuli
Cochlear duct
Oval window
Processsus
mastoideus
External
auditory tube
Scala tympani
Stapes
Uncus
Maleus
Tympanic membrane
Cochlea
Eustachian tube
Hearing histophysiology
Scala vestibuli
Oval
window
Vestibular membrane
Cochlear duct
Tectorial membrane
Organ of Corti
Round
window
Basilar
membrane
Cochlear
nerve
Spiral
ganglion
Scala tympani
Functions
of audiovestibular organ
1. Organ of Corti – hearing
2. Maculae of saccule – gravity
and vibration
3. Maculae of utricle - gravity and
linear acceleration
4. Ampullary crests – circular
accelaration and equilibrium
Deafness
1. Conductive loss – problem is
connected with disorders of sound
waves passage from external
environment to inner ear
2. Sensory-neural – problem of
nerves
3. Pressbyacussis - aging