Good Health Through The Nose - the functions of our nose by gabyion

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									GOOD HEALTH THROUGH THE NOSE:
CAN YOU TELL THE SMELL?
By, Dr. A. B. John,
Consultant Ear, Nose & Throat Surgeon
Mt. Elizabeth Medical Centre.

It’s More than Skin Deep

As one critically examines his nose the obvious feature is its appearance. It
should be well proportioned and balance with the rest of the face.
What exactly this is is debatable. It is not infrequently complicated by the
surgeon’s preference and the patient’s desire. A famous aesthetic nose
surgeon once described the “perfect” nose as that which will bring out the
patient’s eyes. It should not be too disproportionate in any one of its
anatomic components so as to catch an observer’s attention.

Besides our appearance, the nose functions in important physiological roles
to maintain our good health. It functions in breathing, cleansing and
humidification of the air.

The Sense of Smell

Our sense of smell is one of the most intense connections to our memory. A
whiff of the perfume your deceased grandmother used to wear raises a
strong mental image of her. Smelling freshly brewed coffee is enough to get
some people out of bed in the morning. Smelling good food makes us
hungry even though we ate just an hour ago. Smelling our spouse on the
pillow helps us fall comfortably asleep.

The Mechanism of Smell (olfaction)

Smell is a result of input from several cranial nerves. The olfactory nerve
(Cranial Nerve 1) stimulation is most necessary for our sense of smell.

Molecules given off from the various types of scents, requires to reach the
top of the nose cavity, where the olfactory (smell) lining cells are located.
Airflow is required to get to these lining cells. These smell cells have nerve
fibers which connect to the base of the brain (the olfactory bulb) through
tiny holes in the skull at the roof of the nose cavity. From the base of the
brain, nerve fibers then connect to the olfactory cortex of the brain where it
is perceived as a distinct smell.

Our sense of smell is linked with “odor associations” with previous
experiences. Odor associations, once established, are difficult to erase from
memory, even if the association is forgotten or seems irrational.
Studies have shown that by the age of 6 to 10 days, infants prefer a pad from
their own mother’s breast as opposed to one from a strange mother.
Somewhere between the ages of 2 to 7 years, children start to show odor
preferences, and these are similar to those of adults living in the same area.
Our sense of smell elicits such strong memories that it is often used
clinically in coma arousal therapy for patients in a deep coma.


Pheromones are chemicals released by a member of a species and received
through its scent by another member resulting in a specific action or
developmental process. For example, a male hamster knows whether the
female hamster is receptive to his reproductive advances. Studies have
suggested similar olfactory communication may be going on in humans.
The search for a human pheromone has been conducted for many years and
various “biological odorants” refined from human urine, armpit secretions.
and vaginal secretions have been used.

Disorders of Smell (Olfactory Dysfunction)

There are three types smell disorders. Decreased ability to perceive smells,
distorted quality of perceived smells, perceived odor when no odorants are
present.

The first type is the most common. It often is the result of a blocked nose
passage and/or sinus disease. It can also occur after head injury, when the
smell nerve fibers at the base of the brain are torn by the force of the trauma.
Other causes, such as nose and brain tumors, toxic chemical exposure, even
cigarette smoke exposure can be associated with the loss of the sense of
smell.

The sense of taste is intertwined with our sense of smell. When aromas of
food are gone, food tastes flat. These sufferers select food by texture, color
and custom, rather than a zest for flavor. They cannot smell if food has gone
bad. They look for changes in appearance. For example, the lumpy
character of sour milk. People invariably lose weight when they lose their
sense of smell.

There is a real danger of fires and exposure to noxious gases. People with a
total loss of smell have been involved in at least one accident from this
problem. Smoke alarms are an absolute necessity.

Sufferers should be evaluated by a doctor to determine the cause and
treatment for the loss of smell.



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