Presentation on theme: "Sight Hearing Taste Smell Touching"— Presentation transcript:
1 Sight Hearing Taste Smell Touching THE SENSESSightHearingTasteSmellTouching
2 General Sense Organs widely distributed throughout the body detect stimuli (pain, touch, temperature, pressure);Ex.: free nerve endings, Meisners & Paciniancorpuscles
3 types of stimuli include: Special Sense Organslarge and complex grouping of specialized receptors (eye, ear, tongue, nose)types of stimuli include:Photoreceptors lightChemoreceptors chemicalsMechanoreceptors movement
4 Converting a Stimulus into a Sensation 1. Detect stimulus.2. Stimulus converted to anerve impulse.3. Nerveimpulse perceivedas a sensationin the CNS.
5 THE EYE (photoreceptors) http://www.youtube.com/watch?v=GMGSw3GDyJQ CORNEA – transparent part of sclera that covers the Iristough outer coat;the white of the eyePUPIL – holein center of the IrisIRIS – colored partSCLERA
6 contains rods (night vision) and cones (colorvision)-pigmented layerthat preventsscattering of light-nourishes eyeCiliary muscle – muscles that control the opening & closing of the eye
7 fluid in anterior of lens fluid in posterior of lens
17 through the canal, strike the eardrum, and cause it to vibrate. sound waves travelthrough the canal, strike theeardrum, and cause it tovibrate.(function)- contains hairs that respond to ear fluid set in motion by sound wavesEustachian Tube: connects middleear to the throat
20 chemicals (odors/tastes) must be dissolved in nasal mucus / saliva in order to be detected; sent as an impulse to be interpretedolfactory receptors (detect odors) are extremely sensitive but easily fatiguedimpulses are closely associated with areas of the brain important in memory / emotiona cold that interferes with olfactory receptors will dull taste sensations
22 Concept Check #1 1. What are 3 types of receptors that your special sense organs detect. State the organ thatdetects each stimuli.Photoreceptors – eyeChemoreceptors–tongue/noseMechanoreceptors - ear2. Explain how a stimulus turns into a sensation.a) stimulus detected b) converted into an impulsec) Perceived as a sensation in the CNS3. Draw a picture of an eye and label the cornea, sclera, pupil, & iris.4. What are the 2 layers behind the sclera?Choroid – prevents scattering of lightRetina – contains rods & cones for night / day vision.
23 Concept Check #25. How does the lens change to view distant and near objects?Distant – lens flattens Near – lens curves6. What happens during normal focusing?Clear, upside down image on retina – brain rights it automatically.7. Name and describe any 3 diseases/disorders associated with the eye.Myopia, hyperopia, colorblindness, glaucoma, astigmatism8. Draw the ear and label the pinna (auricle), external auditory canal, ossicles, eustachian tube, and cochlea.
24 Concept Check #3 9. Why is the ear considered a mechanoreceptor? Detects fluid movements set in motion by sound waves10. What must happen 1st before odors and tastes can be interpreted as stimuli?dissolved in mucus and/or saliva11. Draw a picture of the tongue and label the location of the 4 different taste sensations.