Chapter 8 - Taste And Smell

Question 1

Odors detectable by CN V

Answer 1

Strong (gas, ammonia)

Question 2

5 tastes

Answer 2

Umami (savory, L-amino acids)
Sweet (energy-rich)
Salt (electrolyte balance)
Bitter/Sour (danger)

Question 3

Location of taste receptor cells and taste buds

Answer 3

Receptor cells: Buds (bundles of cells), chemosensory cells, ciliated, smooth muscle cells in airway, GI tract (neuroendocrine cells)

Buds: Tonge papillae
Also SP, larynx, pharynx, epiglottis (CN X)

Question 4

Tongue papillae

Answer 4

Fungiform- Ant 2/3, 1-15 buds each, VII. 750.

Circumvallate- 8-12
Foliate- also posterior, lateral. Dozens of buds.

Filiform- throughout, no buds, for mechanical distribution of chemicals

Question 5

Taste pathway

Answer 5

CN entre stem
Converge forming solitary tract
Thalamus
Ínsula (gustatory cortex…deep within lateral fissure)

Question 6

Olfactory epithelium location

Answer 6

Septum, S/M turbinates

Pseudostrat columnar 
Bipolar cells (apical dendrite cilia, basal to axon cross cirbiform)
Basal cells (regen)
Sustentacular (mucous later maintenance, odors dissolve)
Each neuron has one receptor type. We can distinguish over 1k odorants

Question 7

Central processing smell

Answer 7

Bipolar axon…same receptor axons converge in bulb…to frontal lobe/temporal lobe

Amygdala and hippocampus also have regions that respond to olfaction (emotion, memory)

Question 8

Causes of Taste Disorders

Answer 8

Transport (inflammation, dry mouth, poor hygiene)

Sensory (medication, rads, endocrine, infection, chemicals)

Neural transmission (damage to nerves, TBI)

Question 9

Causes of smell disorders

Answer 9

Conductive (inflammation, obstruction, mucus change)

Sensory (Head trauma, sinus Dz, URI, chemicals)

Neural (injury to bulb/cortex)

24-40% over 50 have olfactory dysfxn