What tastes Good?

Smell and Taste

Smell Olfactory

The organs of taste & smellSmell:

A. Olfactory membrane:– Contains over 15 million nerve cells

(stimulated by odorous substances)

B. Conditions needed for odours to be perceived:– Be in a gaseous state– Contain a sufficient number of odorous molecules; in high

concentration– Be carried by the air to the olfactory membrane

C. Chain reaction involved in smelling:

– Receiver = Nose– It receives the stimuli which are odours

– Transformer = Nerve cells of olfactory membrane– They transform the odours into nerve impulses

– Conductor = Olfactory nerve– It conducts nerve impulses from the olfactory

membrane to the olfactory bulb in the brain

– Analyzer = Brain– It analyses incoming nerve impulses from the

olfactory nerve

The smell part of the brain is in the limbic region, and is connected to feeling and memory.

Taste (the tongue):Taste (the tongue):• mainly composed of muscles.• covered with a mucous membrane.• Small nodules of tissue (papillae) cover the

upper surface of the tongue.• Between the papillae are the taste buds,

which provide the sense of taste. • In addition to taste, the tongue functions in

moving food to aid chewing and swallowing, • It is also important in speech.

Taste (tongue):A. Taste buds or papillae (location &

function):

– Tongue is a muscular organ that contains most of the body’s taste buds

B. Conditions needed for tastes to be perceived:– Be in solution in the saliva.– Contain a sufficient number of flavourful

molecules– Come into contact with the papillae (taste

buds)

Video

C. Chain reaction involved in taste:

– Receiver = Tongue– Receives the stimuli which is tastes

– Transformer = Taste buds– Transforms tastes into nerve impulses

– Conductor = Gustatory nerve– Conducts nerve impulses to the taste center of

the brain

– Analyzer = Brain– Analyzed incoming nerve impulses from the

gustatory nerve

D. 4 basic taste sensations:Salty, Sweet, Sour, BitterTongue to label