Anatomy and Physiology of the Nose and Throat
What is the nose?
Your nose helps you to breathe and to smell. The inner part of the nose is above the
roof of the mouth. The nose is made up of:
External meatus. Triangular-shaped projection in the center of the face.
External nostrils. Two chambers divided by the septum.
Septum. Made up mainly of cartilage and bone and covered by mucous membranes. The cartilage
also gives shape and support to the outer part of the nose.
Nasal passages. Passages that are lined with mucous membranes and tiny hairs (cilia) that help to
filter the air.
Sinuses. Four pairs of air-filled cavities, also lined with mucous membranes.
What are sinuses?
The sinuses are cavities, or air-filled pockets, near the nasal passage. As in the
nasal passage, the sinuses are lined with mucous membranes. There are 4 different
types of sinuses:
Ethmoid sinus. This sinus is located inside the face, around the area of the bridge of the nose.
It is present at birth, and continues to grow.
Maxillary sinus. This sinus is located inside the face, around the area of the cheeks. It is also present
at birth, and continues to grow.
Frontal sinus. This sinus is located inside the face, in the area of the forehead. It does not develop
until around 7 years of age.
Sphenoid sinus. This sinus is located deep in the face, behind the nose. It does not typically develop
until the teen years.
What is the throat?
The throat is a ring-like muscular tube. It is the passageway for air, food, and liquid.
It also helps in forming speech. The throat is made up of:
Voice box (larynx). The larynx is a cylindrical grouping of cartilage, muscles, and soft tissue that
contains the vocal cords. The vocal cords are the upper opening into the windpipe
(trachea), the passageway to the lungs.
Epiglottis. A flap of soft tissue located just above the vocal cords. The epiglottis folds down
over the vocal cords to prevent food and irritants from entering the lungs.
Tonsils and adenoids. They are made up of lymph tissue and are located at the back and the sides of the
mouth. They protect against infection. But they don't really have a function after