Friday, 4-8-Histology of visual, vestibular, and auditory systems (Olinger) Flashcards
List the components of the outer tunic:
sclera and cornea
list the components of the middle tunic
uvea, choroid, iris, and ciliary body
list the components of the inner tunic:
retina
Regarding the outer tunic, the __ is transparent and the rest of the wall of the eye is opaque and lined by the middle of vascular pigmented layers that absorb light which is known as the __
cornea
sclera
the basal cells of the corneal epithelium are anchored to Bowman’s layer by ___.
Myelinated nerves can be found in the __ of the cornea.
After crossing __ layer, nerves become unmyelinated and extend toward the surface in the intercellular spaces of the corneal epithelium
___ part of the cornea is permeable to air oxygen used for various oxidative rxns, in particular glutathione reduction and oxidation
hemidesmosomes
stroma
Bowman’s
corneal endothelium
In the posterior 2/3 of the eye, the vascular layer is called the ___. In the anterior part of the eye the vascular layer thickens to form the ___ and have ciliary processes that extend inward from it.
The smooth muscle of the ciliary body regulates the tension of the zonule or suspensory ligament of the lens and, therefore, is an important element in the mechanism of __
choroid
ciliary body
accomodation
contraction of the __ relaxes the tension exerted by the zonular fibers on the lens during accomodation
ciliary muscles
What separates the anterior chamber from the posterior chamber?
the iris –> anterior surface lacks epithelial lining, posterior surface is lined by a dual layer of pigmented epithelial cells, a direct continuation of the pigmented layer of the retina.
___ consists of myoepithelial cells, contains alpha-adrenergic receptors and is innervated by sympathetic nerve fibers.
dilator pupillae-contraction causes pupil dilation or mydriasis
___ consists of smooth muscle cells, has Ach receptors and innervated by parasympathetic nerve fibers.
sphincter pupillae-contraction reduces the diameter of the pupil (miosis)
Aqueous humor is secreted by the __
epithelial cells of the cilliary processes
List the cell types for the following retinal neurons:
Photoreceptor neurons: ___
Conducting neurons: ___
Association neurons: ___
Supporting neuroglial cells: ___
rods and cones
bipolar and ganglion cells
horizontal and amacrine cells
Muller cell
This is the only photoreceptor present in the fovea: ___
cones-where fine detail is present
Where are the nuclei of rods and cones present?
The axons of the rods and cones project into the __ layer and synapse with dendrites of the __ cells
in the outer nuclear layer
outer plexiform
bipolar
Nuclei of the bipolar cells contribute to the __ layer
Axons of the bipolar cells synapse with dendrites of the ganglion cells in the __ layer
Axons of the ganglion cells become part of the ___
inner nuclear
inner plexiform
optic n.
The __ corresponds to junctional complexes (zonula adherens) between rods, cones, and Muller cells
__ cells synapse with several rods and cones
__ cells synapse with axons of bipolar cells and dendrites of ganglion cells
outer limiting membrane
horizontal
amacrine
At the __, tightly packed cones are arranged at an angle to the pigmented layer.
fovea centralis
The axons of the ganglion cells turn into the optic n. at the ___, which lacks photoreeptors and corresponds to the blind spot of the retina
optic disk
The __ is a yellow spot produced by xanthophyll pigments within retinal cells, which may absorb short wavelength light and provides for central vision. In its center, the __ is for high-quality vision
macula lutea
fovea
Cones are concentrated in the ___ and are responsible for acute vision and color distinction.
macula
Detachment of the retina is a separation of 2 layers of the retina. It can be caused by:
trauma, vascular disease, metabolic disorders, and aging
The 2 genes for the red and green photopigment reside on the __ chromosome and contribute to red-green color blindness
X
Trace the pathway of the flow of aqueous humor
From the ciliary body through the posterior chamber –> pupil –> anterior chamber –> trabecular meshwork –> canal of schlemm –> aqueous veins –> episcleral veins
Blockage of aqueous humor where can lead to glaucoma?
at the canal of schlemm (most common)
inflammation preventing aq humor from reaching trabecular meshwork
__ extend from the ciliary epitheium to the equatorial region of the capsule and hold the lens in place
zonular fibers
When the ajor proteins of the lens become insoluble, opacity of the lens develops. This condition is known as:
cataracts
__ secrete a lipid-containing product that retards evaporation of the tear film. Infections and disruption of these causes chalazion (swelling of eyelid)
Tarsal glands
The __ is a stratified-to-columnar epithelium with mucus-secreting goblet cells, supported by a thin lamina propria. It lines the anterior surface of the eyeball up to the limbus and the inner surface of the eyelid
conjunctiva
The 3 semicircular ducts (superior, posterior, horizontal) open into the ___
Each ampulla contains ___. Sensory receptors inside of this respond to the position of the head, generating nerve impulses necessary for correcting the position of the body
utricle
crista ampullaris
ductules emerging from the utricle and saccule join to form the ___
endolymphatic duct
the endolymphatic duct ends in a dilated endolymphatic sac located in the __
subdural space of the brain
The ___ connects the saccule to the base of the membranous coiled cochlear duct or scala media
ductus reuniens
the __ extends from the vestibular area (which contains the saccule and the utricle) to the subarachnoid space around the brain
The __ fluid has a composition similar to CSF surround the membranous labyrinth
perilymphatic duct
perilymph
The __ are sensory receptor areas located in the wall of the saccule and utricle. They are concerned with the detection of directional movement of the head
maculae
The position of the macula in the utricle is __.
The position of the macula in the saccule is ___.
horizontal
vertical
Inward movement toward the kinocilium deforms the plasma membrane and triggers ___
Displacement of the stereocilia away from the kinocilium lifts the kinocilium and causes __
depolarization
hyperpolarization
__ hair cells predominate at the ridge of the crista, where as ___ hair cells are more numerous at the base
Type I
Type II
Which scala contains endolymph?
Which scale contains perilymph?
endolymph=scala media
perilymph=scala vestibule and tympani
The __ at the apex or cupula of the cochlea links the perilymph-filled scala vestibule and scala tympani
helicotrema
An inward movement of the stapes against the oval window-caused by airborne sound-is transmitted to the cochlead partition by the noncompressible ___
perilymph fluid
The osseous ___ is a bony shelf projecting from the modiolus. It forms canals for the cochlear nerve fibers
spiral lamina
The ___ is located in the scala media and extends the full length of the basilar membrane. Its sensory receptors are hair cells
organ of corti
Which hair cells are in direct contact with the tectorial membrane?
outer hair cells
This membrane separates endolymph from perilymph and moves up in response to perilymph movement in the scala tympani, causing taller stereocilia of the outer hair cells to hit the tectorial membrane
Basilar membrane
