The outside part of the nose that we can see is made up of the external meatus, the triangle-shaped object in the center of the face between the eyes. It contains the external nostrils, two chambers that are divided by the septum. The septum is mostly made up of cartilage and bone and is covered by mucus membranes. Without the cartilage in the septum, the outer part of the nose would lose its shape and support.

Inside are nasal passages that are lined with mucus membranes and tiny hairs called cilia that act as filters, cleaning out foreign debris from air that is inhaled. Near the nasal passages are the sinuses, air-filled cavities that also are lined with mucus membranes.

The four pair of sinuses are:

  1. 1) Ethmoid Sinus - located near the
    bridge of the nose
  2. 2) Maxillary Sinus - located near the area
    of the cheeks
  3. 3) Frontal Sinus - located near the forehead
  4. 4) Sphenoid Sinus - located behind the nose

When these cavities become blocked by mucus from colds or allergies, swelling of the mucus membranes may increase pressure and can cause discomfort.


Source: http://www.childrenshospital.org/az/Site1366/mainpageS1366P0.html