In class activity 9.3 & 9.4

Identify the structure of the olfactory epithelium

Box 1: olfactory tract Box 2: mitral cells Box 3: glomeruli Box 4: olfactory bulb Box 5: parts of olfactory nerves Box 6: basal cells Box 7: olfactory receptor cells Box 8: supporting cells Box 9: olfactory cilia Box 10: olfactory gland

Use the following figure to answer questions below:

Was is an electrode? - device that conducts electrical charges. Why is the tongue-machine interface an important component of the visual substitution system? - it receives visual input from the camera that is then sent to the tongue as electrical signals

Place the events of olfactory transduction in order.

1. An odorant binds to an olfactory receptor protein in the plasma membrane of an olfactory cilium. 2. Binding of the odorant to the olfactory receptor protein stimulates a G protein known as Golf (olf = olfactory) 3. Golf activates adenylyl cyclase to produce the second messenger cAMP. 4. cAMP opens a cation channel that allows mainly Na+ and Ca2+ ions to enter the cytosol. 5. The influx of Na+ and Ca2+ causes a depolarizing receptor potential to form in the membrane of the olfactory receptor cell. 6. If the depolarization reaches threshold, an action potentials is generated along the axon of the olfactory receptor cell.

Use the following graph to answer questions below:

What is the independent variable in this graph? - Snellen ratio of visual acuity What is the dependent variable in this graph? - Percent correct Which Snellen ration on the graph indicates the best visual acuity (or smallest item that subjects are trying to "see"" with their tongue)? -20/240 What general trend to you see in the graph? -Percent correct decreases with the more challenging or smaller type. Is there a difference in performance between blind and sighted subjects? What is the difference? -The blind subjects seem to do slightly better than the sighted subjects. Does training have any impact on the results? -yes, it seems to increase visual acuity. Why did authors present blind and sighted with training data together? -There was no difference in the performance between the groups with training. Or possibly they had a small sample size and had to combine them .

(___Blank 1___) produce mucus that moistens the surface of olfactory epithelium and dissolves odorants so that transduction can occur (___Blank 2___) are chemicals that bind toad stimulate the receptors in the olfactory cilia; the threshold for detecting odors is (____low/high____) Bundles of axons of olfactory receptor cells form the right and left (_____blank 4___) nerves, which is cranial nerve (____blank 5____) The olfactory nerves extend to extend to parts of the rain known as the (___blank 6___); which contain ball-like arrangements called (___blank 7___) Second-order neurons of the olfactory pathway, found within each glomerulus, are called (___blank 8___) Axons of mitral cells from the (____blank 9___) some of these axons project to the (___blank 10___) in the (___blank 11__) lobe, where conscious awareness of smell occurs. From the olfactory cortex, a pathway extends via the thalamus to the (___Blank 12___) cortex. (__Blank 13___) cells are sensory neurons that respond to olfactory stimuli; olfactory transduction occurs in the cilia that extend from their dendrites; cilia contain olfactory receptor proteins that detect inhaled odorants. (___Blank 14___) cells provide physical support to the olfactory receptor cells and help detoxify chemicals that come in contact with the olfactory epithelium. (___blank 15___) cells are stem that continually undergo cell division to produce new olfactory receptor cells, which live for only about two months before being replaced.

1. Olfactory glands 2. Odorants 3. low 4. Olfactory 5. CNI 6. olfactory bulbs 7. glomeruli 8. mitral cells 9. olfactory tract 10. olfactory cortex 11. temporal 12. orbitofrontal 13. olfactory receptor 14. supporting 15. basal

Match terms 1. Taste buds are found in the elevations on the tongue called: 2. Each taste bud has three type of cells: 3. An opening in the taste bud where several microvilli project from each gustatory receptor cell to the tongue's surface 4. Stem cells that produce supporting cells, which then develop into gustatory receptor cells. 5. Gustatory receptor cells that synapse with the first-order taste neurons of the gustatory pathway 6. Chemicals that stimulate gustatory receptor cells 7. From the taste buds, AP propagate along cranial nerves to this region of the medulla oblongata. 8. From. the thalamus, axons project to this area in the insulation of the cerebral cortex for conscious awareness and discrimination of taste sensations.

1. papillae 2. supporting, gustatory receptors and basal 3. taste pore 4. basal cells 5. modified epithelial cells 6. tastants 7. gustatory nucleus 8. gustatory cortex

Match the five primary tastes on RIGHT with their definitions on LEFT 1. caused by the presence of sodium ions (Na+) in food, most commonly found as NaCl (table salt) 2. produced by H ions (H+) released from acids, for example, lemons are sour due to containing citric acid 3. elicited by sugars such as glucose, fructose and sucrose and artificial sugars 4. caused by a wide variety of substances; aversion to this taste serves as a protection against ingesting harmful substances 5. described as "meaty" or "savory" and is elicited by amino acids (especially glutamate that are present in food.

1. salty taste 2. sour taste 3. sweet taste 4. bitter taste 5. umami taste

Can your Tongue "see"? The eyes are arguably the most important special sense in the body. Vision gives us a great deal of information about the world around us. Losing that sense or never having had it changes the way that someone is able to relate to the world. Researches in the present study used a vision substitution system that allows subjects, both blind and sighted, toes the world with their tongue. Were subjects actually able to "see" the world with their tongue? Article description: Blind and sighted individuals were fitted with a Visio substitution system that uses a TV camera, a tongue electrode array, a human-machine interface, and a computer. The camera was pointed at whatever the subject was trying to "see." The Snellen falling W was used in its various orientations, some large and some quite small, to determine visual acuity of the subjects using the vision substitution system.

What do the eyes detect? - Visible light What part of the eye is responsible fro converting light into AP? - retina Was does acuity mean? - sharpness of perception Where in the eye is visual acuity the highest? - fovea