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³»¸ö ¡í °¨°¢±â°ü ¡í ¼ö¿ëü °¨°¢ ¼ö¿ëü Á¾·ù : °¨°¢¼¼Æ÷ ¼¼Æ÷Á¾·ù :- ¾Ï¼¼Æ÷, °¨°¢¼¼Æ÷, ½Å°æ¼¼Æ÷ ½ÅÈ£Àü´Þ - °¨°¢¼¼Æ÷ : Receptor Á¾·ù - ½Å°æ¼¼Æ÷ : Àü±â½ÅÈ£, ½Å°æÀü´Þ¹°Áú, È£¸£¸ó - °¨°¢¿¬ÇÕ : ½ÅÈ£ÁõÆø - 7TM : G protein - 6TM : ¿Â°¢ - ±Û·çŽ»ê ¼ö¿ëü - Áö´ÉÇü ¼¾¼ ÈÄ°¢¼¼Æ÷ : 30~60ÀÏ °£°Ý Àç»ý ÈÄ°¢¼ö¿ë±â : Àΰ£ 5~6¹é¸¸°³, Åä³¢ 1¾ï°³, °³ 2¾ï2õ¸¸°³ ³úÀÇ ÈÄ°¢½Å°æ±¸ 5%, Áãµî ¾ßÇ༺µ¿¹° ¾à 20% ¹Ì·Ú : Àΰ£ 9,000°³, µÅÁö Åä³¢µî Æ÷À¯·ù 15,000 ~ 18,000°³ Taste : ¹Ì·Ú Total number of human taste buds (tongue, palate, cheeks) = 10,000 Number of taste buds on the tongue = 9,000 Height of taste bud = 50-100 microns Diameter of taste bud = 30-60 microns Number of receptors on each taste bud = 50-150 Diameter of taste receptor = 10 micron Diameter of taste fiber = less than 4 micron Taste threshold for quinine sulfate = 3.376 mg/liter water Smell Number of human olfactory receptor cells = 12 million Number of rabbit olfactory receptor cells = 100 million Number of dog olfactory receptor cells = 1 billion Number of bloodhound olfactory receptor cells = 4 billion Surface area of olfactory epithelium (contains olfactory receptor cells) in humans = 10 cm2 Surface area of bloodhound olfactory epithelium = 59 in2 Area of olfactory epithelium in some dogs = 170 cm2 Area of olfactory epithelium in cats = 21 cm2 Thickness of olfactory epithelium mucous layer = 20-50 microns. Diameter of olfactory receptor axons = 0.1-0.2 micron Diameter of distal end olfactory receptor cell = 1 micron Diameter of olfactory receptor cell = 40-50 micron Number of cilia per olfactory receptor cell = 10-30 Length of cilia on olfactory receptor cell = 100-150 micron Concentration for detection threshold of musk = 0.00004 mg/liter air Vision Length of eyeball (adult) = 24.2 mm Length of eyeball (newborn) = 16.5 mm Volume of eyeball = 5.5 cm3 Weight of eyeball = 7.5 g Average time between blinks = 2.8 seconds Average duration of a single blink = 0.1-0.4 seconds Thickness of cornea = ~0.5 mm in center; ~1 mm in periphery Diameter of cornea = 11.5 mm Thickness of lens = 4 mm Diameter of lens = 9 mm Composition of lens = 65% water; 35% protein Nerves in lens = 0 Blood vessels in lens = 0 Number of retinal receptor cells = 5-6 million cones; 120-140 million rods Number of retinal ganglion cells = 800 thousand to 1 million Number of fibers in optic nerve = 1,200,000 Number of neurons in lateral geniculate body = 570,000 Number of cells in visual cortex (area 17) = 538,000,000 Wavelength of visible light (human) = 400-700 nm Amount of light necessary to excite a rod = 1 photon Amount of light necessary to excite a cone = 100 photons Location of the greatest density of rods = 20o from fovea Highest density of rods = 160,000 per mm2 Peak density of rods (cat) = 400,000 per mm2 Density of cones in fovea = 200,000 per mm2 Diameter of fovea = 1.5 mm Intraocular pressure = 10-20 mm Hg Volume of orbit = 30 ml Area of retina = 2,500 mm2 Thickness of retina = 120 microns (ranges from 100 to 230 microns) Production rate of aqueous humor = 2 microliters/min Turnover of aqueous humor = 15 times/day % volume of eye occupied by the vitreous = 80% Maximal sensitivity of red cones = 570 nm Maximal sensitivity of green cones = 540 nm Maximal sensitivity of blue cones = 440 nm More Facts and Figures about the Human Retina from WebVision. Audition Surface area of the tympanic membrane = 85mm2 Length of the eustachian tube = 3.5 to 3.9 cm Number of hair cells in cochlea = 3,500 inner hair cells; 12,000 outer hair cells Number of fibers in auditory nerve = 30,000 Length of auditory nerve = 2.5 cm Number of neurons in cochlear nuclei = 8,800 Number of neurons in inferior colliculus = 392,000 Number of neurons in medial geniculate body = 570,000 Number of neurons in auditory cortex = 100,000,000 Most sensitive range of human hearing = 1,000-4,000 Hz Length of external auditory meatus (ear canal) = 2.7 cm Diameter of external auditory meatus (ear canal)= 0.7 cm Weight of malleus = 23 mg; length of malleus = 8-9 mm Weight of incus = 30 mg; dimensions of incus = 5 mm by 7 mm Weight of stapes = 3-4 mg; dimensions of stapes = 3.5 mm high, 3 mm long, 1.4 mm wide Length of cochlea = 35 mm Width of cochlea = 10 mm Number of turns in the cochlea = 2.2-2.9 Length of basilar membrane = 25-35 mm Width of basilar membrane = 150 microns (at base of cochlea) Auditory Pain Threshold = 130 db Threshold for hearing damage = 90 db for an extended period of time Touch Weight of skin (adult human) = 9 lb.(4.1 kg) Surface area of skin (adult human) = 3,000 in2 (~1.8 m2) Number of tactile receptors in the hand = 17,000 Number of nerve endings in hand = 1,300 per in2 von Frey threshold (Face) = 5 mg 2 point threshold (Finger) = 2-3 mm Length of Meissner corpuscle = 90 - 120 micron Density of receptors on finger tips = 2,500 per cm2 Density of Meissner's corpuscles on finger tips = 1,500 per cm2 Density of Merkel's cells on finger tips = 750 per cm2 Density of Pacinian corpuscles on finger tips = 75 per cm2 Density of Ruffini's corpuscles on finger tips = 75 per cm2 Thermal pain threshold = 45oC |
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