know your body nose and tongue

A human nose  can distinguish around  4000 different  substances.We  use our nose  to breathe  and to smell.We can differentiate  the god and bad odor.Smell  floats in the air.We smell  things  we take in air  through  our noses.The sensory cells  in the nose,detect the smell and send message to the brain.Our sense  of smell  also  help  our sense of taste.So, our sense of smell and taste are  closely linked.
Our tongue  receptors   differentiate  only four  types of taste qualities; sweet,sour,salt,and bitter.There  are thousands  of taste  buds all over  the tongue.These   survive  only for a matter of days  under go  rapid and continuous   replacement.Each  taste  bud  consist  of  sensory  cells  that  are  connected    to  the mid brain through taste  fibers.The  sensors  send  massage  to  the  brain about what we  are  eating.The  front  of the tongue  taste  sweet things,the sides of the tongue  taste  salty  and sour things.The back  of the tongue  tastes bitter  things.The tongue can also  feel  heat,cold,and pain.Many  of the things  that we may  think that  we are tasting ,we are actually   smelling.Our  nose  is  our personal  air  conditioning system;it  warms  cold air,cools  hot air and filters  impurities.
NOSE

TONGUE