Ch. 15 Flashcards
(17 cards)
Olfaction
smell
Gustation
Taste
optic
vision
Vestibucholear
hearing and equilibrium
Smell
- Both chemical senses
- Sensations arise from interaction of molecule with specific receptor
- Odor from foods can pass from mouth to nasal cavity
*Both propagate to limbic systems
- strong emotions and memories
Odors
about 10,000 different odors recognized
Five primary taste
sour, sweet, bitter, salt, savory
Olfactory receptor cells
olfactory hairs (non-motile cilia) extending from dendrites
Olfactory glands
Secrete mucus through ducts to moisten and dissolve chemicals in air (odorants)
Olfactory Epithelial Cells
bipolar neurons
- olfactory hairs respond to inhaled chemicals (odorants)
Supporting cells
- Detoxify chemicals
- Electrically insulate receptors
- Provide support and nourishment
Basal Cells
Continually divide to produce new olfactory receptor cells
Olfactory Pathway:
- Olfactory nerves
- Bundles of axons from bipolar olfactory receptor cells
*Olfactory Bulb
- Bundle of gray matter below cerebrum frontal lobe
- synapse of receptor cell axons with dendrites and cell bodies
*Olfactory tract:
- Some axons project to cerebral cortex primary olfactory area of temporal lobe for awareness of smell
- Other axons project to limbic system and hypothalamus for emotional and memory-evoked responses
- Others project from primary olfactory area to frontal lobe for odor identification and discrimination
Taste
*Papillae on tongue
- Vallate, fungiform, foliate: elevations with taste buds
- Filiform increase friction and have tactile receptors
Taste Bud Cells
- Gustatory receptor cells
- Responds to dissolved chemicals (tastants)
*Supporting cells
- Surround receptor cells in oval body of taste bud
*Basal cells
-Stem cells produce supporting cells
3 cranial nerves serve taste buds
- Facial – anterior 2/3 of tongue
- Glossopharyngeal – posterior 1/3 of tongue
- Vagus – throat and epiglottis
