1. Chapter 14.1 Pages 446-448

2. 2 TASTE AND SMELL TASTE AND SMELLTASTE AND SMELLTASTE AND SMELL  Taste receptors  Found in diff. locations in diff. species  Octopuses – tentacles  Crayfish – antennae  Insects - legs 2

3.   in humans, receptor cells for taste are modified epithelial cells organized into taste buds  there are five taste perceptions:  sweet  sour  salty  bitter  umami (savory)(elicited by glutamate)  Once dissolved, specific chemicals stimulate receptors Taste

4. 4 1) Taste 4 types of taste that are stimulated by dissolved chemicals in specific taste buds: Sweet Salty Sour Bitter

5. 5 5 Figure 16.4 (a) Specialized hair- like receptor ends in the tongue detect specific chemicals, Axons from the sensory neurons are shown in yellow, (b) Taste buds of a rabbit tongue, The taste bud appears as a bulblike structure,

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7.   Taste receptors http://www.mhhe.com/biosci/genbio /espv2/data/animals/003/index.html  Click on taste sensation 7 Taste receptors and olfactory create the perception of taste

8.  Smell (olfaction)  Detection of a specific airborne chemicals that stimulates an olfactory cell to produce action potential that is perceived in the olfactory bulb.  Olfactory receptor cells are neurons that line the upper portion of the nasal cavity  Binding of odorant molecules to receptors triggers a signal transduction pathway, sending action potentials to the brain

9. 9 DETECTING SMELL

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11. 11 sensory adaptationOlfactory cells demonstrate sensory adaptation People who live in cities with pulp mills adjust to odor Odor seems to fade after a short period of time  Taste  http://www.bbc.co.uk/science/ humanbody/body/factfiles/taste/ taste_ani_f5.swf http://www.bbc.co.uk/science/ humanbody/body/factfiles/taste/ taste_ani_f5.swf  Smell  http://www.bbc.co.uk/science/ humanbody/body/factfiles/smell/ smell_ani_f5.swf http://www.bbc.co.uk/science/ humanbody/body/factfiles/smell/ smell_ani_f5.swf 11

12. 12 Each mechanoreceptor is a modified dendrite of a sensory neuron 3) Sensory receptors in human skin Despite an incredible collection of specialized sensory receptors, much of environment remains undetected Skin receptors http://www.sumanasinc.com/webcontent/animations/content/skinreceptors.html http://www.sumanasinc.com/webcontent/animations/content/skinreceptors.html

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14.  14 Senses game  http://www.bbc.co.uk/science/humanbody/body/ interactives/senseschallenge/ http://www.bbc.co.uk/science/humanbody/body/ interactives/senseschallenge/