With what our tongue is made of?

TONGUE :

STRUCTURE OF THE TONGUE:

• Tongue is made up of voluntary muscles, it contains about 10 thousand taste buds which are located in the walls of papillae. 

RELATION BETWEEN SMELL AND TASTE:-

• Taste is also a sense like that of smell based on identifying chemicals in food and the texture of it. 
• Senses of taste and smell have a close and cooperative working relationship. 
• Some  flavours really come from odour. Example:- Taste of an onion is odour not flavour.  
• When you have a  cold, food seems tasteless because your nasal passages are blocked. 
• Our sense of taste (or) gustation, involves 4 qualities - sweet, bitter, sour and salty. 
• Fifth taste is Umami (savoury flavour) found in protein rich foods such as meat, seafood and cheese. 

TASTE BUDS:-

• Each taste bud has a cavity with a pore called taste pore. 
• Epithelial cells, surrounding the taste buds form taste receptor cells. 

TASTE RECEPTOR CELLS:-

• These are located in the taste buds on the top and side of the tongue, sample flavours from food and drink as they pass on the way to stomach. 
• These receptors cluster in small mucous membrane projections called "papillae", each papillae is of a particular shape. 

TYPES OF PAPILLAE ON OUR TONGUE:-

1. FILIFORM PAPILLAE: These are flap like structures, these are not the site of taste sensation because taste buds are not present on this papillae. 
2. FUNGIFORM PAPILLAE: These are roundish structures on our tongue and have taste buds. 
3. CIRCUMVALLATE PAPILLAE: These are large roundish structures at the back of the tongue and have taste buds. 
4. FOLIATE PAPILLAE: These are bump like structures present at the sides of the tongue and can sense the taste. 

FUNCTION OF NERVE FIBRE IN TONGUE:

• Each receptor cell connects to a nerve fibre. 
• All the nerve fibres connect to main nerves that carry messages to the brain and spinal cord for further processing. 
• Agglutination specialized nerve "hot line"  carries taste messages to the specialized regions of the brain. 

DEVELOPMENT CHANGES IN TASTE:

• Infants  have heightened taste sensitivity that is why babies try to sense everything by taste. 
• As age increases this super sensitivity decreases that is the reason why many elderly people complain that food has lost its taste.