Anatomy Eye Test

protect eye

produce an oily secretion that lubricates eye

• membrane that line eyelids and covers outer part of eyeball
• secrete mucus to lubricate eye

• protective layer of the eye
• anterior most part of the sclera

• colored part of eye (pigmented diaphragm)
• contains muscles to open and close the pupil

• opening to allow light to reach lens
• size adjusts with light
• -smaller: more light
• -larger: less light

• major refractory (light bending) structure
• focuses light into retina
• shape is changed by ciliary muscle for close focus
• divides eye into 2 chambers (anterior; posterior)

• contains clear watery aqueous humor
• -provides nutrients to lens and cornea
• drains through the canal of schlemn

• vitreous humor
• -reinforce eyeball
• -gel like

• lacrimal gland above lateral end of eye
• release dilute salt solution (tears) through several small ducts
• travel to lacrimal canals medially, into lacrimal sac, and finally nasolacrimal duct
• lacrimal secretion contains antibodies and lysozyme which kills bacteria
• protects and lubricates the eye
• -emotional tears "crying" is poorly understood

provide gross eye movements

three tunics

• thick white connective tissue
• center is transparent cornea containing nerve endings
• -can be transplanted without rejection, non vascular

• vascular, brings nutrients to the eye
• 3 regions
• -ciliary body where lens is attached
• -iris pigmented opening
• -pupil where light enters
• contains a dark pigment to prevent light from scattering inside the eye

• contains photoreceptor cells (rods and cores)
• -fovea centralis (means "pit")
• --area of most acute vision
• --responsible for sharp central vision for reading, watching, driving, and any activity where visual detail is of primary importance

• point where the optic nerve leaves the back of the eyeball
• lacks photoreceptors
• overlap of the visual fields and inputs from both eyes to each optic cortex provide for depth perception

• light passes through pupil to lens
• lens focuses light onto retina
• photoreceptors of the retina create impulses
• impulse travels up optic nerve to brain

cornea > aqueous humor > (through pupil) > aqueous humor > lens > vitreous humor > retina

• autonomic nervous system
• ciliary body- muscles that alter lens curvature
• radial and circular muscles of iris which control pupil size

• rectus and oblique control eye movements
• convergence, movement of eyes medially to view close objects and moving objects

sudden exposure to bright light, pupils constrict, prevents damage to photoreceptors

constriction of pupils to view close objects

inflammation of the conjunctiva, red, irritated eyes caused by bacteria or virus

deterioration of the neural retina, vitamin A deficiency

• lack of all three cones, sex-linked disorder, mostly in males
• most common lack of red or green receptors

lens hard and opaque as we age, treatment is removal of lens and lens transplant

increased pressure due to backup of aqueous humor fluid, causes blindness slowly over time

• distant objects appear blurred
• images are focused in front of the retina rather than on it
• also called short sight or nearsightedness

• light focused behind the retina instead of directly on it
• inability to see near objects clearly
• caused by a shortened eyeball or a misshaped lens
• also called farsightedness or hypermetropia

• unequal curvature of one or more refractive surfaces, usually the cornea
• prevents light rays from focusing clearly at a single point on the retina, resulting in blurred vision

pinna, external acoustic meatus, tympanic membrane or eardrum

shell shaped outer ear

• part of outer ear
• short chamber
• contains ceruminous glands which secrete earwax

• part of outer ear
• amplifies sound vibrations and transmits vibrations to 3 ossicles (bones): malleus, incus, and stapes

• air filled cavity in the temporal bone
• two openings (oval and round window)

• connecting the middle and inner ear
• stapes transmits vibrations into the inner ear

membrane covered opening in the inner wall of the middle ear that compensates for changes in cochlear pressure

• part of middle ear
• attaches ear to throat
• normally flat and closed but swallowing or yawning opens it to equalize pressure in ear with atmospheric pressure

• part of middle ear
• contains the ossicles

• inner ear
• bony chambers with 3 subdivisions 
• function to maintain equilibrium

• part of osseous
• contains mechanoreceptors
• organ of Corti which contains sensory "hair" cells
• measures pressure

• part of osseous
• responsible for static equilibrium

part of osseous

• temporary
• damage of mechanical factors
• caused by build up of earwax, fusion of ossicles otitis media
• treatment: hearing aid

• damage to nervous system
• damage to cochlear nerve, hair cells in organ of corti
• -caused by blood clot in auditory cortex of brain, listening to loud noise

• middle ear inflammation in children
• eardrum bulges, pus, pressure
• treatment: myringotomy
• -tiny tube implanted in eardrum allows pus to drain

• sense of smell
• olfactory receptor cells have olfactory hairs covered in mucus
• olfactory filaments are stimulated by scent chemical dissolved in mucus
• filaments make up the olfactory nerve which carries impulses to olfactory cortex of brain

• covered in papillae
• chemicals dissolve in saliva
• chemoreceptors in taste buds create impulse

• sweet (OH-)
• sour (H+)
• bitter (alkaloids)
• salty (metal ions)
• umami (delicious in Japanese)
• -amino acid glutamate
• beef taste and msg