Nervous system: smell, taste, touch

Question 1

How do we smell? Part 1

Answer 1

When we breathe in, smells enter our nose. The molecules of the substance we breathe in go to the roof of each nasal cavity and dissolve on a patch of olfactory membrane. The smell receptors on the membrane react with scent molecules, stimulating nerve impulses in the receptor cells.

Question 2

How do we smell? Part 2: understanding smell

Answer 2

Olfactory nerves transmit signals from the receptor cells and transmit these signals to olfactory bulbs, then via olfactory tracts to the smell centre in the limbic system deep in the brain.

Question 3

What are food’s flavour’s?

Answer 3

Partly smells detected by the olfactory membrane in the nasal cavity

Question 4

What do tastes depend on?

Answer 4

The tongue

Question 5

How do we taste dry food?

Answer 5

We moisten it with saliva in the mouth. Particles of food dissolved in the saliva stimulate taste buds in the sides of papillae. The taste buds’ sensitive hairs pass nerve signals to nerve fibres and these transmit taste signals to the brain

Question 6

Papillae

Answer 6

Tiny bumps on the tongue, where taste buds are

Question 7

Back of tongue

Answer 7

Bitter

Question 8

Left and right side of tongue

Answer 8

Sour

Question 9

Near the tip of the tongue

Answer 9

Salty

Question 10

Tip of the tongue

Answer 10

Sweet

Question 11

What do specialised nerve endings in the skin do?

Answer 11

Send signals that the brain identifies as touch, pain, pressure, heat, and cold