Task of Tongue and Nose

The Tongue is the only muscle in our body which is attached at one end.

This enables it to move and perform certain important tasks. The tongue assumes a variety of forms and positions to enable us to make different sounds while speaking.

The mucous membrane that covers the tongue helps in the taking, holding and grinding of food. Our tongue also sends messages to the brain or the central nervous system about what we are eating and drinking.

Another important feature of our tongue is that the taste buds are located on the tongue.

The surface of the tongue is covered with little bumps called the papillae. The taste buds are located on the walls of these papillae. These taste buds are able to register threedifferent sensations - sweet, salt and bitter. Different parts of the tongue are sensitive to different tastes.

The back is sesitive to bitter , sides of the tongue are sensitive to sour and salt. The tip of the tongue picks up the sweet taste.

The above funtions of the tongue clearly prove the importance of this organ in the life of human being.

Man's sense of smell is poorly developed compared to that of other creatures. The initial place where the messages of smelling are received is located in the nose .

This organ of smell is quite small. It is really a mucous membrane containing nerve cells, which is surrounded by nerve fibres, kept moist by mucous glands. Through the cells, delicate hairs stick out into the nasal cavity.

The tips of these hairs are covered by a fatty layer of cells. The substance that we smell must actually be dissolved in these layers, before we can smell it.

Also, the substance that has an odour must be both volatile and part of an oily substance that can dissolve in the fatty layer.

There is a small centre for smell in the brain, which receives these messages from the nerves in the nose and tells us what we are smelling .