Hearing and Vision

Anatomy of the Ear - model of ear

External Ear

Tympanic Membrane - ear drum

Middle Ear

Auditory Ossicles

Inner Ear

Cochlea - for hearing

Oval Window - membrane that connects to auditory ossicles

Round Window - membrane that permits pressure changes

Vestibule - for equilibrium

Saccule and Utricle- for sensation of gravity, acceleration

Semicircular Canals - for sensation of head rotation

Anterior SC- respond to nodding of head

Posterior SC- respond to sideways tilting of head

Lateral SC - respond to horizontal rotation of head

Ampulla - contains the sensory receptors

Bony Labyrinth - bone surrounding Cochlea and Vestibule

Organization of the Cochlea

Scala Vestibuli - contains Perilymph moved by the oval window

Scala Tympani - contains Perilymph that moves the round window

Scala Media - contains Endolymph and Organ of Corti

Vestibular Membrane - separates Scala Vestibuli and Scala Media

Basilar Membrane - separates Scala Tympani and Scala Media

Tectorial Membrane - overlies the organ of Corti

Organ of Corti - contains Hair Cells (accessory sensory receptors)


Anatomy of the Eye - model of eye

Fibrous Tunic - dense fibrous connective tissue covering eye

Sclera - covers all but front of eye

Cornea - transparent portion in front of eye

Vascular Tunic (Uvea) - blood vessels, lymphatics and intrinsic muscles

Iris - most anterior

Pupil - opening in iris

Ciliary body - next to iris

Ciliary Muscles - concentrically organized in ciliary body

Choroid - under the sclera

Neural Tunic - innermost layer

Retina - contains photoreceptors

Fovea - region of retina containing dense concentration of cones

Optic Nerve - contains the axons of the retinal ganglion cells

Anterior Chamber - between iris and cornea

Posterior Chamber - between iris and suspensory ligaments

Aqueous Humor - in anterior chamber and posterior chamber

provides for nutrient and waste transport for cornea and lens

Vitreous Chamber - between lens and retina

Vitreous Humor - behind lens and suspensory ligament in interior of eye

gelatinous material that stabilizes the shape of the eye

Organization of the Retina - slide of retina

Pigment cells - attached to choroid

Rods and cones - light sensitive part faces the pigment cells

Outer segment - contains the light sensitive pigments

Inner segment - contains the cellular organelles

Bipolar cells - synapse on the photoreceptors

Ganglion cells - synapse on bipolar cells - axons in optic nerve


David G. Ward, Ph.D.  Last modified by wardd 23 May, 2006