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| Visual Accessory Organs: Eyelid, Lacrimal Apparatus(Tears), Extrinsic Eye Muscle, Eyelashes, Eyebrows |
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| Hollow and Spherical Shape, 3 Layers: Outer Fibrous Tunic, Middle Vascular Tunic, Inner Nervous Tunic |
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| Composed of Connective Tissue & Smooth. Pupil is the hole inside the Iris. Dim light stimulates radial muscles and pupil dilates. Bright light stimulates circular muscles & pupil constricts |
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Cornea(front of the eye): anterior portion, transparent, light transmission, light refraction.
Sclera(White of the Eye): posterior portion, opaque with no light, protection.
Light=waves, goes through the air in straight path. Waves will eventually bend(refraction), refraction happens through the cornea, it must refract for the fovea centralis(back of the eye) |
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| Superior Rectus(contracts up & medially), Inferior Rectus(rotates eye down & medially), Medial Rectus (Rotates Medially), Lateral Rectus (rotates laterally), Superior Oblique (diagonal down & lateral), Inferior Oblique (rotates up & laterally) |
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Iris: Anterior Portion, Pigmented, Controls light intensity
Ciliary Body: no blood vessels, pigmented, holds lends, moves lens for focusing
Choroid Coat: has blood vessels, provides blood supply, melanocytes absorbs extra light, prevents glare |
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Definition
| Transparent, biconvex, lies behind the iris, largely composed of lens fibers, elastic, held in place by suspensory ligaments of ciliary body, changes shape in order to refract |
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| Forms internal ring around the front of the eye, ciliary process(radiating folds), ciliary muscles(contract & relax to move lens) |
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| Retina, contains visual receptors, continuous with optic nerve, ends just behind margin of ciliary body, composed of several layers, macula lutea- yellowish spot in retina, fovea centralis- center of macula lutea(produces sharper vision), optic disc-blind spot; contains no visual receptors, vitreous body thick gel that holds retina flat against choroid coat |
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Definition
| Long & thin projections, contain light sensitive pigment(rhodopsin), hundred times more sensitive to light than cone, provide vision in dim light, produce colorless vision, produce outlines of objects, rhodopsin doesn't work with light & slow adjustment, decomposes with light. |
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Definition
| Filled with Aqueous Humor.(maintains the shape), Secreted by epithelium inner surface of ciliary body, provides nutrition, leaves cavity through canal of schlemm(hole in cornea for fluid to leave and come out in tears), salt in tears can block the canal, fluid builds up causing pressure which is gloccoma. |
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Contains vitreous humor: thick gel that holds retina against choroid coat
Hold shape- stigmitizim(none round eye) |
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| as light enters eye, it is refracted by:(convex surface of cornea & convex surface of lens) image focused on retina is upside down and reversed from left to right, we sense with our brains not our body. |
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Definition
| Provides perception of distance & depth , results from formation of two slightly different retinal images, |
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Term
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Definition
| short (blunt) projections, contain light sensitive pigments called erythrolabe, chlorolabe, and cyanolabe(3 major clear images with light), provide vision in bright light, produce sharp images, produce color vision, focus in center |
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Definition
General(touch & temperature): receptors that are widely distributed throughout the body
Special( hearing, taste, sight, smell): specialized receptors confined to structures in head (localized) |
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Definition
Ear- Organ of Hearing
3 Sections: Outer Ear, Middle Ear, Inner Ear. |
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Definition
Auricle(Pinnae)= collects sound waves
External Acoustic(Auditory) Meatus: lined with ceruminous glands & hairs, terminates @ tympanic membrane
Tympanic Membrane: vibrates in response to sound wave, nothing gets pass membrane |
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Term
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Definition
Tympanic Cavity: Air- Filled space in temporal bone (no water)
Auditory Ossicles: vibrate in response to tympanic membrane, parts include Malleus, Incus, Stapes
Oval Window: opening in wall of Tympanic Cavity, stapes vibrates against it to move fluids in inner ear |
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Term
| "Eustachian Tube"- Auditory Tube |
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Definition
| Connects the Mid Ear to the Pharynx, Helps maintain equal pressure on both sides of tympanic membrane, usually closed by valve- like flaps in the pharynx, otitis media occurs here(mid ear infection) |
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Definition
| Air pressure must be equal on both sides of tympanic to properly heal, going from high to low altitude causes air pressure to be greater outside & may push tympanic membrane in, "popping" of ears occurs when pressure equalizes, opening valves may quicken process |
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Term
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Definition
3 Parts of the Labryinth(Maze):
Cochlea(snail shell): filled with fluid, functions in hearing(receptors)
Semicircular Canals: functions in equilibrium
Vestibule: functions in equilbrium |
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Term
| Organ of Corti(Hearing Receptors) |
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Definition
| Group of hearing receptor cells(hair), located on the upper surface of the basilar membrane, different frequencies of vibrations move different prats of basilar membrane, particular sound frequencies causes hairs of receptors to bend, nerve impulses generated, membranes between fluid when oval window vibrates to the perilymph across membranes to the endolymph, when vibration comes hair(organ of corti) bends |
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Term
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Definition
Static- stayimg same, with no body movements. This happens in the vestibule, sense of position of head when the body is not moving.
Dynamic: the balance the body uses when moving. The semicircular canals are responsible for sensing rotation & movement of the head and body |
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Term
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Definition
Utricle-static equilibrium: communicates with saccule & membranous portion of semicircular canal
Saccule: communicates with the cochlear duct
Maculae: hair cells of utricle & saccule |
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Term
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Definition
| Responds to changes in head position, bending of hairs result in generation of nerve impulse, otoliths add weight making gelatinous sheet more responsive. When moving during static equilibrium, otoliths moves to the gravity hair cells bend, and sends signals to the brain |
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Term
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Definition
3 Canals @ right angles
Ampulla: swelling of membranous labrynith that communicates with vestibule
Crista Ampullaris: sensory organ of ampulla, hair cells & supporting cell, rapid turns of head or body stimulates hair cells
Cerebellum receives information about bod movements and signals appriopriately to the muscle |
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Term
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Definition
Conductive Deafness: usually temporary, interference with transmission of vibrations to inner ear, accumulated wax, changes in tympanic membrane,
Sensorineural Deafness: nerves & conduction, damage to cochlea or vestibulocochlear nerve, prolonged loud sounds, older age but to bad to repair |
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Term
| Generations of Sensory Impulses from the Ear |
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Definition
1.) Sound waves enter the external acoustic meatus
2.)Causes tympanic membrane to vibrate
3.) Auditory Ossicles amplify & transmit vibration
4.) Movement of the Stapes @ oval window transmits vibrations to perilymph is scala vesti
5.) Vibrations pass through vestibular membrane & enter endolymph of cochlear duct
6.) Different frequencies of vibration in endolymph move specific regions of basilar membrane, thus stimulating certain receptors
7.) a receptor cell becomes depolarized; its membrane becomes more permeable to calcium
8.) in the prescence of calcium, vesticles at the base of receptor cells release a neurotransmitter
9.)Neurotransmitter stimulates ends of nerby sensory neurons
10.) Sensory impulses are triggered on fibers of cochlear branch of vestibulocochlear nerve
11.) auditory cortex of temporal lobe interprets the sensory impulses |
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