Histology Of The Eye And Ear Flashcards
What are the outer ear structures
Pinna (Auricle): Cartilage covered by thin skin; collects and funnels sound.
External Auditory Canal: Lined with stratified squamous epithelium; contains ceruminous glands (produce ear wax).
What are the middle ear structures
Tympanic Membrane: Translates sound waves into vibrations.
Ossicles: Malleus, Incus, Stapes—amplify sound vibrations.
Eustachian Tube: Equalizes pressure; lined with pseudostratified ciliated columnar epithelium.
Clinical correlations of the ear
Conductive Deafness: Blockage/fixation in sound conduction (e.g., otosclerosis).
Otitis Media: Middle ear infection; common in children.
What are the functions of hair cells and where can they be found?
Function: Mechanoelectric transduction (convert mechanical energy to electrical signals).
Locations: Organ of Corti (hearing), maculae (utricle/saccule), cristae ampullares (semicircular canals).
What are the components of the inner ear
Cochlea: Hearing; contains Organ of Corti with hair cells.
Vestibular System: Balance; includes semicircular canals (rotational movement), utricle, and saccule (linear movement).
What are the layers of the eye?
Fibrous Tunic: Cornea (transparent, avascular) and Sclera (opaque, protective).
Vascular Tunic (Uvea): Choroid (nourishment), Ciliary Body (accommodation), Iris (pupil regulation).
Neural Tunic: Retina (photoreception).
What are the layers of the retina
Photoreceptors: Rods (low light) and Cones (color, high acuity).
Outer Nuclear Layer: Contains cell bodies of rods and cones.
Ganglion Cell Layer: Axons form the optic nerve.
Functions of the cornea lens and iris
Cornea: Refracts light.
Lens: Focuses light (adjusts shape via ciliary muscles).
Iris: Controls pupil size (sphincter/dilator pupillae muscles).
What are the specialized regions of the retina?
Fovea Centralis: High cone density; greatest visual acuity.
Optic Disc: Blind spot (no photoreceptors).
Clinical correlates of the eye
Cataract: Lens opacity.
Glaucoma: Increased intraocular pressure damages optic nerve.
Which structure detects rotational head movements?
Semicircular canals.
Where are the cell bodies of photoreceptors located?
Outer nuclear layer of the retina.
