Nose and Sinuses
The nose cleans, warms and humidifies inspired air. The nose is partitioned
into two cavities by a medial septum. The side wall of the nose is further
partitioned by three projections know as turbinates that extend the length of
the nasal cavity. The nasolacrimal duct drains tears from the eyes into the
nose. The turbinates filter the incoming air removing particles as small as
pollen grains. The nasal mucosa actively expands and contracts regulating air
flow through the nose. Usually, only one side of the nose is open to airflow,
the other is partially obstructed; the airway alternates.
Sinuses are air-containing cavities that surround the nasal cavity and are
connected to it. The nose and paranasal sinuses are covered with a mucosal
lining that hosts immune cells and secretes mucus. The surface cells have moving
hairs that push mucous out of the sinuses into the nose in a programmed
sequence. Allergens and pollutants trapped in the nose cause local tissue
swelling and may obstruct the sinus drainage holes. Bacterial infection tends to
develop in blocked sinuses. Airborne chemicals are absorbed through the nasal
mucosa into the circulation. Tobacco smoke is the number one source of
carcinogens that cause cancers in the mouth, throat, larynx and bronchi.
Rhinitis means inflammation in the nose. Rhinitis may be intermittent or
persistent. The cause of intermittent rhinitis is sometimes obvious; symptoms
only occur at a specific time and place. Allergic rhinitis is one of the most
obvious environmental diseases. The cause of persistent rhinitis is often
concealed and some patients with this problem are treated with drugs and never
discover the cause. Allergic responses in the nose are more easily studied than
in the lung. There is reason to believe that there are similarities.
Allergic rhinitis and asthma go together in attack patterns when the
allergens are airborne. Hay fever is the prototype of type I allergy and the
mechanism was thought to be a straightforward histamine-mediated response to
inhaled antigen. The early immediate response is characterized by sneezing and
nasal discharge, often profuse. Antigen triggers mast cells to degranulate and
preformed mediators such as histamine. Cytokines are released, and at the same
time the lipid mediators, leukotrienes, are generated from arachidonic acid.
Antihistamines are effective in the early stages of this inflammatory process.
Learn more about rhinitis
Nasal congestion is the main symptom of the common cold. Nasal congestion can
be more distressing than cough or sore throat, since it compromises breathing.
Congestion in infants interferes with feeding, since infants must breathe
through their noses while breast-feeding. Adults can clear their nose by
blowing, but infants are unable to clear the nasal airway on their own. See Coughs and Colds
The middle ear is connected to the throat by the Eustachian tube and often
participates in infections and allergic inflammation that starts in the nose and
Middle Ear Problems
The book, Air and Breathing helps you understand the causes of
breathing disorders. The solutions involve improving air quality and solving
food problems with diet revision. Indoor air quality issues at home and at work
are discussed. Air pollution and airborne causes of lung disease are also
discussed with advice about improving both indoor and outdoor air quality.