Edisi Nota : Nose

1.  The nose is sensory organ for smell.

2.  Cells sensitive to smell (smell receptors) are found on the top of the nasal cavity.

3.  Structure of the human nose.

a.          The human nose has a cavity lined with epithelium tissue.

b.          On the surface of the epithelium tissue are the sensory cells known as olfactory cells.

c.           The surface of the nasal cavity is moist because of the mucus secreted by the cells of a gland.

d.          The nasal cavity has a pair of external opening (nostrils) which have hair to filter dust from the air inhaled through the nose.

4.  When we have a cold or flu, a lot of mucus is produce. The smell receptors are surrounded by this thick layer of mucus and very little of chemical vapor gets to the smell receptors. Therefore, the smell receptors do not get stimulated enough to effectively function as a sensory organ of smell. The sensitivity of the nose towards stimuli is influenced by the following factors:

i.            The strength of the smell. A stronger smell will be detected by the nose easily compared with a weaker smell.

ii.          The presence of mucus in the nose. A lot of mucus will reduce the sensitivity of the nose.