Taste and Smell

Question 1

What are the 5 basic tastes?

Answer 1

1. Salty (Na+)
2. Sour (H+)
3. Sweet (glucose)
4. Bitter (no single molecule)
5. Umami (amino acids)

Question 2

What are the taste receptors in the tongue?

Answer 2

Circumvallate papillae, foliate papillae, fungiform papillae
Papillae contain taste buds which contain taste pores and cells

Question 3

How do tastants create a stimulus?

Answer 3

• Small charged particles directly change membrane potential (e.g Na+ and H+)
• Others bound bu receptors, trigger a transduction process inside the cell

Question 4

How is taste stimulus processed?

Answer 4

• Axons from solitary tract relay to the thalamus

- Thalamus relays to the gustatory cortex and orbifrontal cortex

Question 5

What are the requirements for an odorant

Answer 5

must be small, volatile and hydrophobic

Question 6

Where in the nose is smell detected?

Answer 6

Top of the nose contains the olifactory cleft with the olifactory epithelium

Question 7

What two theories may explain how odorants are detected?

Answer 7

1. Shape of structure determines smell, which is why stereoisomers smell differently
2. Molecule vibrations determine smell, which is why rats can smell different isotopes

Question 8

How is olefactory information transmitted to the cortex?

Answer 8

Directly

Question 9

Where in the brain is smell processed?

Answer 9

1. Primary olfactory complex
2. Secondary olfactory complex
3. Limbic system

Question 10

Where is the primary olfactory cortex and the secondary olfactory complex located?

Answer 10

primary - temporal lobe

secondary - frontal lobe

Question 11

How is the olfactory epithelium organised?

Answer 11

Olfactory cilia converge on a glomerulus which connects to a mitrial cell (multiple of these in an olfactory bulb)