Unit 2 Topic 4 Flashcards
What makes up the outer tunic of the eye?
cornea and sclera
What is the structure of the cornea?
avascular and transparent due to 17 orthogonal arrangment of collagen fiber; layer of nonkeratinized stratified squamous
What is the primary refractive element of the eye?
cornea
What is the structure of the sclera?
dense connective tissue with collagen fibers running in various directions and interspersed elastic fibers
What is the main function of the outer tunic?
supportive
What is the main function of the middle tunic?
vascular
Where is the choroid located?
between the sclera and the retina
What part of the eye is primarily WBCs in loose connective tissue?
Choroid
What is Burch’s membrane?
contains collagen and elastin; assists in refraction between the pigmented layer and the retina
What is the contractile diapraghm that controls the amount of light that enters the eye?
Iris
What is the thickened anterior portion of the vascular coat located between the iris and choroid?
Ciliary body
What is the lens connected to and how is it connected?
ciliary body; zona occludens holds the lens
What produces the aqueous humor?
ciliary body
How is the lens transparent?
due to intracellular crystallins
Is the lens vascular or avascular?
avascular
What is the superficial pigmented layer that absorbs light to precent reflection and has long microvilli?
retina
Where is the photosensitive region with cells located?
deep neural layer of the retina
What part of the eye is highly vascularized connective tissue with stromal melanocytes and fibroblasts?
iris
What controls eye color?
melanocytes
What is the sphincter papillae?
smooth muscle that facilitates constriction through PNS innervation and found at the pupillary margin
What are the 2 fused layers of the Iris?
-anterior epithelium of myoepithelial cells that constitutes the dilator papillae muscle that facilitates dilation by SNS innervation
-posterior highly pigmented epithelium that blocks light not coming from the pupil
What is the watery juice in the anterior and posterior chamber that is constantly in production and resorption?
aqueous humor
What drains the aqueous humor?
drained by Canal of Schlemm into the venous system
Viterous Humor
gelatinous cushion in viterous chamber or posterior segment
What produces the viterous humor?
non pigmented cells of the ciliary body
What is the function of the viterous humor?
diffues pressure by acting as a shock absorber and distributes force
What is the path of light through the eye?
-inner limiting membrane
-Nerve fiber layer
-Layer of ganglion cells
-Inner plexiform
-Inner nuclear layer
-Outer plexiform
-Outer nuclear layer
-Outer limiting membrane
-Photoreceptive
-Retinal pigment epithelium
Where is the crista ampullaris located?
located in ampulla of the semicircular canals of the inner ear
What is the function of the crista ampullaris?
-sense angular movements of the head
-signal transduction through mechanically gated channels following hair cell movement
What is the thing in the crista ampullaris that helps with signal transduction?
hair cells with stereocillia within three semicircular ducts
Where is the maculae located?
in the utricle and saccule of the vestibule of the inner ear
What is the mechanism for maculae?
hair cells with stereocilia; otoliths drag stereocilia
What is the function of maculae?
sense gravity and linear acceleration
Where is the organ of corti located?
located in the cochlea of the inner ear
What is the function of the organ of corti?
signal transduction
Where is the endolymph located?
is located in the membranous labyrinth of Scala media
Where is the perilymph?
contained within the bony membrane of the scala vestibuli and scala tympani
How are mechanical sound waves transduced?
Signal transuction occurs in the spinal organ/ organ of Corti on the floor of the scala media
-The basilar membrane moves up in response to perilymph movement in the scala tympani
-Taller stereocilia of outer hair cells within the endolymph displace
-Ion channels open and K enters the hair cell depolarization
-Hair cells release neurotransmitters at the basal domain
-The cochlear nerve depolarization or hyperpolarized
