UNIT 5 - Taste and smell

Question 1

Papillae - (tongue)

Answer 1

BUMP or projections on the surface of the tongue that give the tongue a slightly abrasive feel.

Question 2

Taste Receptors

Answer 2

• Receptors for taste are chemoreceptors called taste buds (microscopybuds)
• They are mostly located on the tongue in papillae

Question 3

Taste Buds

Answer 3

●Taste buds contain gustatory (taste) cells

●Taste cells have long microvilli called gustatory hairs that project through a taste pore and are bathed in saliva.

●When activated, the other side of the taste cells release neurotransmitter to dendrites of a sensory neuron.

Question 4

Taste Buds

Answer 4

• The sensory dendirtes will then send the taste sensory info to the brain over one of two cranial nerves:
• Facial (vll) - Innervates anterior 2/3 of tongue

-Glossopharyngel (lX) - innervates posterior 1/3 of tongue.

Question 5

Gustatory Pathway

Answer 5

Cranial nerve Vll
Cranial nerve lX
Medulla oblongata
Thalamus
Gustatory cortex in the INSULA

Question 6

Five distinct Tastes

Answer 6

•sweet
•sour
•salty
•bitter
•umami – ex. experienced in “beef flavor”

• Each activates different gustatory cells with different chemoreceptors.

Question 7

Taste % Smell

Answer 7

• Interact closely with one another
• What we think is “taste” is actually about 80% smell

Question 8

Smell

Answer 8

Olfactory

Question 9

Smell Receptors

Answer 9

●Olfactory receptor cells are chemoreceptors located within olfactory epithelium in the roof of the nasal cavity.

●These detect chemicals that get dissolved in mucus.

●These are bipolar
neurons.

Question 10

Olfactory Receptor cells

Answer 10

▪ At terminal end of dendrite, each cell has several long cilia called olfactory cilia.

▪ Olfactory cilia are coated with thin layer of mucus which catches and dissolves airborne chemicals.

Question 11

Olfactory Receptor Cells

Answer 11

▪ These have axons that travel through the cribriform plate of the ethmoid bone and carry impulses to the olfactory bulbs of cranial nerve I located above.

Question 12

Olfactory Pathway

Answer 12

Impulse travels from olfactory bulbs to the olfactory tracts

Question 13

Olfactory Pathways

Answer 13

Olfactory dive in two

THALAMUS ( Olfatory cortes- temporl lobe & portion of frontal lobe ( for conscious interpretation)

& STRUCTURES OF THE LIMBIC SYSTEM ( this is why odors can elicit an emotional response)

Question 14

Taste

Answer 14

Gustation