Term
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Definition
1.Nerve Cells: photoreceptors of the eye and hair cells of ear are example
2. Nerve Endings: nerve endings may be naked or associated with special structure
3. Epithelial Cells: taste cells on tongue |
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Term
| Sensory Receptors respond to specific stimulus such as |
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Definition
-Mechanoreceptors (touch, pressure, vibration, sound, muscle stretch)
-Thermoreceptors (warmth, cold)
-Photoreceptors (light)
-Chemoreceptors (taste, small)
-nociceptors (pain) |
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Term
| Somatic Senses classified on basis where stimulus takes effect |
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Definition
| Extereoceptive senses, Proprioceptive Senses, Visceroceptive Senses |
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Term
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Definition
| concern changes at body surface or even at distance from body such as light, touch, pressure, temp, pain |
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Term
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Definition
| Mediated by receptors in muscles, tendons, and joints. Respond to changes in muscle length, tendon tension, joint angle, deep pressure. |
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Definition
| associated with changes in internal envirionment |
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Term
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Definition
Vision=photoreceptor cells in eye
Hearing=mechanoreceptor cells in ear
Balance=equilibrium cells in ear
Smell (olfaction) |
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Term
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Definition
stimulated by light (eye) leads to changes in the membrane potential of the photoreceptor cells in neural retina
*generate train of action potentials that are transmitted along optic nerve to lateral geniculate nucleus of the thalamus, occipital lobe, to cerebral cortex. |
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Term
| Accessory Structures of eye |
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Definition
1.Eyelids
2.Lacrimal Apparatus
3.Extraocular Muscles |
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Term
| Extraocular Muscles: Superior Rectus |
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Definition
| Rotates eye upward and toward midline |
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Term
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Definition
| Rotates eye downward and toward midline |
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Term
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Definition
| Rotates eye toward midline |
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Term
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Definition
| Rotates eye away from midline |
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Term
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Definition
| Rotates eye downward and away from midline |
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Term
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Definition
| Rotates eye upward and away from midline |
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Term
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Definition
| window of eye that helps focus incoming light rays on retina. LACKS BLOOD VESSELS BUT HAS MANY TINY NERVE ENDINGS that respond to pain and stimuli. |
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Term
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Definition
| composed of fibrous connective tissues |
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Term
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Definition
| Choroid, Iris, Ciliary Body. Highly vascular and contains melanocytes, which contains granules of melanin= absorbs light and prevents light scattering that could degrade visual acuity |
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Term
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Definition
| gives color to eye and contains pupil which is hole in center |
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Term
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Definition
| has ciliary muscles/processes. |
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Term
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Definition
| attached to ciliary processes and help hold the lens in place |
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Term
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Definition
| ciliary muscles adjust tension in suspensory ligaments altering power of lens to ensure that images are sharply focused on retina. |
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Term
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Definition
| production of aqueous humor exceeds rate of removal which causes rise of intraocular pressure |
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Term
| Neural Retina/Retina Pigmented Epithelium |
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Definition
| neural retina is outgrowth of brain. carries out preliminary processing of the signals generated by the photoreceptor cells |
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Term
| 5 cells of neural retina (BPHAG) |
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Definition
1.Photoreceptor cells
2.Horizontal Cells
3.Bipolar Cells
4.Amacrine Cells
5.Ganglion Cells which goes to optic nerve. |
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Term
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Definition
| make up optic nerve which carries signals to lateral geniculate nucleus of thalamus, from where they are transmitted to occipital lobe of cerebral cortex |
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Term
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Definition
| Region of tightly packed cones associated with high visual acuity |
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Term
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Definition
Between neural retina and choroid.
-help regulated passage of nutrients from blood into the retina
-metabolize Vitamin A
-remove fragments of membranes that have been shed by photoreceptor cell outer segments |
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Term
| External/Middle Ear transmit sound to... |
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Definition
| Inner ear where they are converted to electrical signals that are conveyed to brain via cochlear branch of CRANIAL NERVE 8 |
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Term
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Definition
| connects middle ear cavity with pharynx and allows air pressure in middle ear to equalize with atmospheric pressure |
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Term
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Definition
| In inner ear and associated with sense of balance. Consists of Semicircular Canals and utricle/saccule |
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Term
| Semicircular Canals respond to |
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Definition
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Term
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Definition
| sensitive to head tilt hortizontal/vertical acceleration respectively |
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Term
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Definition
| snail like structure associated with hearing and consists of three different parts: scala vestibuli, scala media, and scala tympani |
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Term
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Definition
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Term
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Definition
| filled with endolymph and hair cells located here |
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Definition
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Term
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Definition
| very thin and flexible. separates scala vestibuli and scala media |
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Term
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Definition
| separtes scala media and scala tympani. On surface lies ORGAN OF CORTI which contain hair cells that act as auditory receptor cells. |
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Term
| Neural Pathway of Hearing |
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Definition
1. Sound waves make tympanic membrane vibrate
2. Vibrations transmitted via malleus, incus, and stapes to OVAL WINDOW>
3. vibrations of oval window casues perilymph vibration in scala vestibuli
4. vibrations transmitted through Reissners Membrane through endolymph in scala media
5.Basilar membrane vibrates in response to vibration of of endolymph in scala media, stimulating hair cells in organ of corti
6. Vibrations are then transferred via perilymph in scala tympani to Round Window
7. Vibration of Round window dissipated in the air of the middle ear. |
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Term
| Summary of Pathway of hearing |
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Definition
| Hair cells in organ of corti stimuated --> auditory branch of cranial nerve 8 ---> cochlear nucleus (medulla)---> thalamus ---> cerebral cortex |
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Term
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Definition
| inadequate transmission of sound vibrations to inner ear |
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Term
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Definition
| damage to cochlea or any of the neural structures |
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Term
| Causes of conductive hearing loss |
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Definition
1. accumulation of dry wax on foreign substances in external auditory meatus.
2. Perforated eardrum
3. Deposition of new bone at bone of stapes restricting its mobility |
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Term
| Causes of sensorineural hearing loss |
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Definition
1. Excessively loud noises
2. Tumor in CNS
3. Cerebrovascular accident/stroke |
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Term
| Tilt of head with respect to direction of gravity controlled by: |
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Definition
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Term
| Horizontal linear acceleration controlled by |
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Definition
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Term
| vertical linear acceleration controlled by |
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Definition
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Term
| Head rotation controlled by |
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Definition
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Term
| utricle and saccule are considered |
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Definition
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Term
| small patch of hair cells (in utricle and saccule) and supporting cells in a sensory area is a what? |
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Definition
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Term
| hair of hair cells in macula are in contact with.. |
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Definition
| otolith membrane (sheet of gelatinous membrane) |
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Term
| Semicircular Canals Detect what and consist of how many canals |
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Definition
Head Rotation and 3 semicircular canals
-2 stand vertically and 1 is horizontal |
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Term
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Definition
| in ampula of semicircular canal and consists of group of hair cells |
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Term
| hair of hair cells extend into |
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Definition
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Term
| head rotates what happens to endolymph vs cristae |
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Definition
| inertia of endolymph in semicircular canals tends to keep fluid stationary while cristae move |
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Term
| 2 sense organs in the ear |
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Definition
| Crista Ampularis and MACULAE |
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Term
| Role of semicircular Canals |
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Definition
1. Maintain body balance
2. Maintain stable image on the retina by stabilizing direction of gaze. |
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