Eye and Ear Flashcards
Structure of the eye
Tunica fibrosa -> Uvea -> Retina
Tunica fibrosa
Outer layer of eye. Contains the sclera and cornea
Uvea
2nd layer of eye. Choroid -> ciliary body -> iris
Retina
3rd layer of eye. Contains the neural retina and non-neural retina
Sclera
Connective tissue layer of tunica fibrosa
Cornea
Corneal (outermost layer) -> Bowmen’s membrane -> Stroma (thickest layer) -> Descment’s membrane -> Endothelium
Canal of Schlemm
At the junction of the schlera and cornea. Facilitates calibration of pressure
Choroid
Vascular connective tissue layer filled with blood vessels. Provides nutrients to the sclera and retina
Ciliary body
Contains muscle that can contract and change shape of lens for visual accommodation.
Iris
Contains a double layer of epithelium that has the pigment granules (adjacent to posterior chamber). Continuous with ciliary body
Choriocapillary layer
Subdivision of the choroid that is vascular. Blood vessels are a lot smaller and filled with capillaries
Ciliary processes
Folds of the epithelium in ciliary bodies. Inner layer is pigmented and the outer layer is non pigmented
Zonule fibers
Also called oxytalin fibers. Attached to lens. Form a bridge between ciliary processes and lens
Ora serrata
Transition from neural to non neural retina.
Fovea centralis
Spot in the neural retina that only has cones and gives the greatest visual sharpness.
Neural retina
Outer layer of rods and cones, intermediate layer of bipolar neurons, and internal layer of ganglian cells
Rod cells
only give black to shades of grey and white – rhodopsin
Cone cells
only gives color - variants of iodopsin
Optic nerve
No rods or cones. Central artery of the retina flows through here
Non-neural retina
Double layer of epithelium that lines the ciliary body and back of the iris
Lens epithelium
simple cuboidal to columnar (cellular)
Lens capsule
proteoglycans, type IV collagen (connective tissue)
Eyelid
conjunctiva -> tarsus plate -> Meibomian gland (sebaceous) -> orbicular muscle -> eyelashes
Conjunctiva
Mucosa covering portion of sclera continues as lining of internal eyelid, stratified columnar to stratified squamous
Lacrimal apparatus
Produces tears, tubular-alveoli acini, serous
Structure of ear
Outer ear -> middle ear -> inner ear
Outer ear
Pinna -> Auditory canal -> Tympanic membrane
Pinna
Also called the auricle. Outer lobe of ear that contains elastic cartilage and connective tissue
External auditory meatus
Ear canal, lined by epidermis
Tympanum
Ear drum. External epidermis -> middle connective tissue -> inner simple cuboidal/squamous
Middle ear
Consist of the malleus, incus, and stapes which articulate with each other to amplify sound
Inner ear
Contains the bony (outer) and membranous (inner) labyrinth
Inner ear sensory regions
Vestibule, semicircular canals, and cochlea
Vestibule
Composed of utricle & saccule that contain the maculae
Semicircular canals
Contain the cristae ampullares. There are 3 canals: X,Y, and Z.
Cochlea
Contains the oval window, round window, organ of Corti and tectorial membrane. Seashell shaped structure that contains fluid. When sounds waves move in, pressure from the stapes pushes the oval window in and the round window out. The vibration travels down the hair cells of the organ or Corti.
Stapes footprint
Bangs on the chochlea that causes a vibration to move towards the organ or Corti
Organ of corti
Movement of vibration through the tectorial membrane rubs up against the hair cells and gives us the sensation of sound
Tectorial membrane
stimulates the hair cells of the organ or corti
Scala media
Middle duct of cochlea that contains the organ of corti. Contains endolymph
Endolymph
Fluid that maintains viability of the cells of the organ of corti. Secreted by the stria vascularis
Macula
Located in the utricle and saccule of the vestibule. Perceives linear acceleration and movement. Contains sterocillia embedded in a gelatinous layer with odoliths on top
Odoliths
Calcium carbonate crystals that provide inertia so when you move, the gelatinous layer and stereocilia will move and that is perceived as motion.
Cristae ampullares
Located at the base of semicircular canals within the ampullae to perceive rotation
Sterocilia bundles
hair cells that are connected by small bridges in the macula and cristae ampullaris