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Taste and Smell. Chapter 14.1 Pages 446-448. TASTE AND SMELL. Taste receptors Found in diff. locations in diff. species Octopuses – tentacles Crayfish – antennae Insects - legs. 2. Taste. in humans, receptor cells for taste are modified epithelial cells organized into taste buds
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Taste and Smell Chapter 14.1 Pages 446-448
TASTE AND SMELL Taste receptors Found in diff. locations in diff. species Octopuses – tentacles Crayfish – antennae Insects - legs 2
Taste • 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
1) Taste • 4 types of taste that are stimulated by dissolved chemicals in specific taste buds: • Sweet • Salty • Sour • Bitter
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, 5
Taste receptors http://www.mhhe.com/biosci/genbio/espv2/data/animals/003/index.html • Click on taste sensation • Taste receptors and olfactory create the perception of taste
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
Olfactory 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 • Smell • http://www.bbc.co.uk/science/humanbody/body/factfiles/smell/smell_ani_f5.swf 11
3) Sensory receptors in human skin • Despite an incredible collection of specialized sensory receptors, much of environment remains undetected • Each mechanoreceptor is a modified dendrite of a sensory neuron Skin receptors http://www.sumanasinc.com/webcontent/animations/content/skinreceptors.html
Senses game • http://www.bbc.co.uk/science/humanbody/body/interactives/senseschallenge/