Inner Ear:Basilar Membrane-UNIT 10 TEST 3

The spiral ligament and spiral crest and stria vascularis.

What are on the right here?

INNER ROD OF CORTI and AN OUTER ROD OF CORTI.

What are the 2 sets of corti cells here?

epithelial cells that cover the vestibular lip.They are supporting cells for the inner haircells. They line Internal Spiral Sulcus

What are the Border cells of Held?

at their bases by the bodies of the phalangeal cells, and at their apexes by the phalangeal processes.

What are the Cilia supported by?

supporting cells. Note how rods are widely spaced at bases and converge to meet at the top.

What are the Inner Rods of corti?

(DEITERS CELLS) - 3 rows of phalangeal cells. Similar but not like one inner row of phalangeal cells on left side. Can see spaces where sensory cells will fit.

What are the Outer Pharyngeal Cells

specialized cells that run along margin of Spiral ligament towards Reissner's Membrane. function differently from supporting cells.

What are the Strius Vascularis?

form the base of the outer tunnel or the external spiral sulcus.

What are the cells of Henson and Cells of Claudius?

Reissner's Membrane and Basilar Membrane

What defines the Scala Media?

.16mm and .52mm

What did Keith report about the width of the base of the basilar membrane and it's apex?

.08mm and .50

What did Weaver report about the width of the base of the basilar membrane and it's apex?

on the outer limit of the ARCUATE ZONE of the basilar membrane.

What do the outer Rods of Corti's Base rest on?

the SPIRAL GANGLION,

What do you see in the lower left hand section?

it shows how the basilar membrane is long but we're looking at its width.

What does it show at the bottom of the diagram?

the Tympanic Lip of OSL to the Basilar Crest of the Spiral Ligament

What does the Basilar Membrane extend FROM and TO

a fibrous layer that serves as a footing for spiral organ or Organ of Corti

What does the Basilar Membrane form?

concave at outer edge, forming Internal Spiral Sulcus at same time giving rise to upper extremity called Vestibular Lip, and lower extremity called Tympanic Lip

What does the Spiral Limbus look like and form here?

a serrated appearance - "auditory teeth".

What does the Vestibular Lip look like?

expands at the top to form a thin lamella

What does the ascending phalanx (phalangeal process?)

the junction of the tympanic lip of osseous spiral lamina and the basilar membrane.

What does the base of the Inner Tunnel rest on?

(cuticular plate) contributes to the reticular membrane and separates apexes of neighboring hair cells.

What does the lemella do in the Deiter cells?

the spiral vessel called the VAS SPIRALE.

What is in the center running the length of the Basilar Membrane?

The Vestibular Lip and the Tympanic Lip

What is on the top and bottom of the osseous Spiral Lamina?

INNER SULCUS

What is the 1st fluid filled space?

INNER TUNNEL OF CORTI

What is the 2nd fluid filled space?

phalangeal process. begins near base of hair cell. You can see where hair cell is going to fit right in there.extends all way to apex or top of hair cell.

What is the 2nd part of the Inner Phalangeal Cell?

SPACE OF NUEL

What is the 3rd fluid filled space?

OUTER TUNNEL

What is the 4th fluid filled space?

OUTER SPIRAL SULCUS

What is the 5th fluid filled Space?

perforations along tympanic lip of spiral lamina giving passage to cochlear nerves, opening where nerve fibers leave Organ of Corti.

What is the Habenula Perforata?

unique looking cell-2 parts- body & base rests on spiral lamina near perforate habenula. Base extends to lower limit of inner hair cell. At base of hair cell is upper part of base/body of inner phalangeal Cell.

What is the INNER PHALANGEAL CELL?

triangular space in between the rods contains a fluid called cortilymph.

What is the Inner Tunnel of Corti?

means plate or leaf‐like, and there is a lamella and the apex of the phalangeal process.

What is the Lamella?

net-like. Looks like loosely woven piece of fabric. Space between heads of Phalanges/rods of Corti and tectorial membrane.

What is the Reticular Lamina?

top of diagram. Gelatinous mass of cochlea. Submerged in fluid, mass density greater than fluid it's in.Runs over top of cells ends near border Cells of Hensen.

What is the TECTORIAL MEMBRANE?

the bases of the rods and the basilar membrane ‐

What is the floor of the Inner Tunnel of Corti formed by?

Zona Arcuta or Pars Tecta (the roof), thin and fragile

What is the portion closest to the Spiral Lamina called?

the innermost fragile part called Arcuate Zone.

What is the portion of the Basilar Membrane closest to the Spiral Lamina called?

a layer of mesothelium through which courses vascular tissue

What is the tympanic surface of the Basilar Membrane covered by?

Vascular Covering for basilar membrane.

What is the underneath side facing the scala tympani?

OSSEOUS SPIRAL LAMINA that projects into center of the lumen of osseous vestibule

What is there on the center side?

side perspective of the COCHLEAR DUCT. error on this slide: stapes should fit into vestibule, not into cochlea as shown.

What is this a diagram of?

pushing down on Reissner's Membrane, which affects the Basilar Membrane and energy is released into Scala Vestibuli

What should the sound waves from stapes be doing here in this diagram?

This is a cross section of the Cochlear duct so the pillars and cells go way back throughout the duct

What should we remember about this slide?

the SPIRAL GANGLION

What space shape is between the Lips and what's on the left hand side?

Organ of Corti

What's the collection of cells in the Scala Media?

Pectinate Portion (comb-like) Pectinate Region consists of 2 fibrous layers.

What's the thicker, more rigid part toward the outside wall of the Spiral Ligament called?

continuous with a highly vascular layer of epithelium lining the spiral ligament. They help to form the STRIA VASCULARIS.

Where are the Cells of Claudius here? What do they help to form?

On the top and on the bottom

Where are the Scala Tympani and The Scala Vestibuli?

placed in the organ of Corti. You can see a row of inner hair cells, and 3 rows of outer hair cells.

Where are the sensory cells here?

at the apexes of the hair cells, and they're in contact with the TECTORIAL MEMBRANE (gelatinous mass)

Where are the tufts of cilia?

placed in the cup formed by the base of the inner phalangeal cell

Where is the Inner Hair Cell in this diagram?

lower right portion of Scala Media (cochlear duct), sitting on vestibular lip of spiral lamina‐a thickened periostum, and it narrows as it extends up to Tectorial Membrane. Limbus means border or edge.

Where is the Spiral Limbus?

in the bases of the outer phalangeal cells.

Where is the outer hair cell here?

would run from somewhere near top of inner hair cell over head plates of Pillars of Corti and Inner Hair Cells out to Cells ofHenson.

Where would the Reticular Lamina be here?

What has the Stria Vascularis been compared to?

a "microkidney" and produces endolymph.

What is the Spiral Ganglion?

a collection of nerve fibers that come through the Perforate Habenula. There are a number of these spiraling around from base to apex of cochlea.

The LEAST stiffest end of the Basilar Membrane is at the...

apex

The stiffest end of the Basilar Membrane is at the...

base

Phalangeal Cells/Deiter Cells have a _____ or ____ and a __________ as well.

base, body and pharyngeal process

What does it mean that each cell in the Organ of Corti is unique?

each cell being distinctly different from next cell. Monsters Inc. characters, specialized cells brought together to accomplish a specific function.

What are Rods of Corti made of?

epithelial cells, have slit like spaces between them which permit endolymphto circulate & nerve fibers to pass through.

What do the supporting cells of Organ of Corti not have? What are they there for?

no sensory function; they are there for support and functional purposes.

What is the purpose of the tufts of cilia in the Reticular Lamina?

occupy the spaces in the netlike matrix and project beyond it toward the Tectorial membrane.

HIGH Frequencies come through...

the Scala Tympani near the base of the cochlea.

What's the largest vessel of vascular tissue in the mesothelium that covers the Basilar Membrane called?

the VAS SPIRALE.

The basilar membrane's greatest width is where?

the apex

LOW frequencies come out through where?

the apex of the Scala Media

The basilar membrane's least width is where?

the base

What is the Reticular Lamina composed of?

the inner phalanges, headplates of the inner rods, the phalangeal processes of the outer rods, and of the Deiters cells.

What do Deiter cells help to hold?

the outer hair cells in position.

When the basilar membrane's not stretched...

there's no tension

What is the Stria Vascularis?

these cells are not supporting cells ‐‐ they secrete endolymph fluid.

What is the purpose of the Reticular Lamina?

to lend support to the tops or apexes of the outer hair cells.

If you were traveling down the cochlear duct what would you see?

you'd see Transverse fibers crossing your path. Compare to a corrugated or "washboard" road. There are about 24,000 of these fibers.

What is the stiffness ratio of the Basilar Membrane?

100 to 1

to form a cup that snugly accommodates the basal end of an outer hair cell.

How is the shape of each PHALANGEAL CELL (Cells of Deiters) modified?

on the right

If the limbus is on the left here where would the Spiral Ligament be?

you would separate the Rods into Outer Rods on the right, and Inner Rods on left.

If you separated that black triangle in half vertically, what would happen?

a Layer of Transverse Fibers that are perpendicular to axis of the cochlear duct

On top of the Base Layer of Connective Tissue what layer is there?

What are the Rods of Corti also called?

Pillars of Corti

the nature and frequency of the incoming sound.

The sound wave energy is released into Scala Media depending on what?

a thickening of periosteum known as the SPIRAL LIMBUS.

The upper layer of bone of Spiral Lamina is continuous with what?

What is the Spiral Lamina?

(spiral plate) narrow shelf of bone at apical end of cochlear duct, wider toward basal end. Consists of 2 plates of bones,between which are canals for transmission of peripheral fibers of auditory nerve