Zusammenfassung der Ressource
Gustation and
Olfaction
- Taste
- four qualities
- sweet
- sour
- bitter
- salty
- taste buds
- chemical receptors
concentrated along the edges
and back surface of the tongue
- umami increases
sensitivity of other
taste qualities
- activated by
proteins &
monosodium
glutamate
- receptors are also
found in the roof and
back of the mouth
- even people without a
tongue can taste substances
- hairlike structures project from the top
of each cell into the taste pore (opening
to the outside surface of the tongue)
- when a substance is taken into the
mouth, it interacts with saliva to
form a chemical solution that flows
into the taste pore
- stimulates receptor cells
- provides us with pleasure
- has adaptive significance in
discriminating between
nutrients and toxins
- newborns respond positively
to sugar water and negatively
to bitter substances
- poisonous substances
in nature have bitter
tastes
- hard wired into
our physiology
- sweet substances are
more likely to occur in
nutritious foods
- Smell
- receptors for smell are long cells that project
through the lining of the upper part of the
nasal cavity and into the mucous membrane
- our ability to discriminate between
odours is not well understood
- most popular theory is that olfactory receptors
recognize diverse odours individually rather
than by mixing of receptors
- olfactory receptors
- have receptor structures that
resemble neurotransmitter
binding sites on neurons
- any of potential
odour molecules can
lock into sites that are
tailored to fit them
- receptors that fire
send their input to
olfactory bulb
- forebrain
structure
immediately
above nasal
cavity
- each odorous chemical
excites only a limited portion
of the olfactory bulb
- odours are apparently coded in
terms of the specific area of the
olfactory bulb that is excited
- pheromones
- chemical signals
found in natural
body scents
- may affect human
behaviour in
subtle ways
- no solid evidence to prove
that pheromone substances
make humans "sexually
irresistable"
- menstrual synchrony
- tendency of women who live together
or are close friends to become more
similar in their menstrual cycle