NASAL SEPTUM
NAUSEA
N
Most nasal polyps are noncancerous,
but they may need to be removed if
they cause
nasal obstruction.
nasal septum
The dividing partition
inside the
nose.
The nasal septum con-
sists of cartilage at the front and bone
at the rear, both of which are covered by
mucous membrane.
Disorders include a deviated septum
(twisting of the septum to one side),
which may be present from birth or
caused by injury. Surgery may be needed
if breathing is obstructed.
Injury may also cause a
haematoma
(a
collection of clotted blood) to form bet-
ween the cartilage of the septum and
the wall of one nasal cavity. A haem-
atoma may obstruct breathing and may
become infected, causing an
abscess
that
could require surgical drainage.
Rarely, a hole may be eroded in the
nasal septum by
tuberculosis, syphilis,
Wegener's granulomatosis,
or as a result
of sniffing
cocaine.
nasogastric tube
A narrow plastic tube
that is passed through the nose, down
the oesophagus, and into the stomach.
Nasogastric tubes are commonly used
to suck or drain digestive juices from
the stomach when the intestine is
blocked (as in
pyloric stenosis
) or is not
working properly (as may occur after an
abdominal operation). A nasogastric
tube is also used to give liquid nourish-
ment to patients who cannot eat (see
feeding, artificial),
to obtain specimens
of stomach secretions for examination,
and to wash out the stomach after a
drug overdose or after swallowing a poi-
son (see
lavage, gastric).
nasolacrimal duct
A channel that drains
tears into the nose. The nasolacrimal
duct forms part of the
lacrimal apparatus.
nasopharynx
The passage connecting
the nasal cavity behind the
nose
to the
top of the throat behind the soft
palate
.
The nasopharynx is part of the respira-
tory tract and forms the upper section
of the
pharynx.
During swallowing, the
nasopharynx is sealed off by the soft
palate pressing against the back of the
throat, preventing food from entering. It
contains the lower openings of the
eustachian tubes
(passages connecting
the back of the nose to the middle ear)
NASOPHARYNX
Soft palate
Nasopharynx
Oropharynx
Laryngopharynx
Larynx
Adenoids
Opening of
eustachian
tube
and, in children, the
adenoids
, which can
enlarge to block the nasopharynx, forcing
the child to breathe through the mouth.
nasopharynx, cancer of
A cancerous
tumour of the
nasopharynx
that usually
spreads to the nasal cavity, nasal sinus-
es, base of the skull, and lymph nodes
in the neck.
Cancer of the nasopharynx is rare in the
West but common in the Far East. Most
common at age 40-50, it affects twice as
many men as women. One cause is
believed to be the
Epstein-Barr virus
.
Common first signs are recurrent nose-
bleeds, a runny nose, and voice change.
Loss of sense of smell, double vision,
deafness, paralysis of one side of the
face, and severe pain may develop.
Diagnosis is through a
biopsy
,
MRI
scans, and
X-rays
.
Treatment is usually
with
radiotherapy
, but surgery may also
be performed. If treated early, the out-
look can be good.
natural childbirth
See
childbirth, natural
.
naturopathy
A form of
alternative med-
icine
based on the principle that disease
is a result of the accumulation of waste
products and toxins in the body, and
that symptoms reflect the attempts of
the body to rid itself of these sub-
stances. Practitioners of naturopathy
believe that health is maintained by
avoiding anything artificial or unnatural
in the diet or in the environment.
nausea
The sensation of needing to
vomit. Although nausea may occur with-
out
vomiting
, the causes are the same.
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