Webster's New World Medical Dictionary

socialized medicine
A medical system like that
of a socialist country, in which medical facilities and
payments are under government, rather than pri-
vate, control. Most industrialized nations, including
the US, have medical systems under some combina-
tion of state and private control. For examples,
socialized medicine is practiced in Canada and
Britain.
sodium
The major positive ion (cation) in the
fluid surrounding cells in the body. The chemical
notation for sodium is Na+. When sodium is com-
bined with chloride, the resulting substance is a
crystal called table salt. Excess dietary sodium is
largely excreted in the urine, but too much salt in the
diet tends to increase the blood pressure. Too much
or too little sodium in the blood (called hyperna-
tremia or hyponatremia respectively) can cause cells
to malfunction, and extremes can be fatal. Normal
blood sodium level is 135–145 milliEquivalents/liter
(mEq/L) or 135–145 millimoles/liter (mmol/L) in
international units.
soft palate
The muscular part of the roof of the
mouth. The soft palate is directly behind the hard
palate, and it lacks bone.
soft tissue
All tissues within the body that serve
to support, insulate, or connect the internal struc-
tures of the body in addition to their other functions.
Examples of soft tissue are muscles, nerves, fat, ten-
dons, blood and lymph vessels, and synovial tissues.
solar keratosis
See 
keratosis, actinic.
somatic
Relating to the body, or pertaining to the
body as distinguished from the mind (the psyche).
somatization
The normal, unconscious process
by which psychological distress is expressed as
physical symptoms. For example, a person with
clinical depression may complain of stomach pains
that prove to have no physical cause. Counseling can
be helpful to overcome somatization.
somatostatin
A hormone that is widely distrib-
uted throughout the body, especially in the hypothal-
amus and pancreas, that acts as an important
regulator of endocrine and nervous system function
by inhibiting the secretion of several other hormones
such as growth hormone, insulin, and gastrin.
somatotropin
A growth hormone that is pro-
duced by the anterior pituitary (the front part of
the pituitary gland). Somatotropin acts by stimu-
lating the release of another hormone called
somatomedin by the liver, thereby causing growth to
occur. Somatotropin is given to children with pitu-
itary dwarfism (short stature due to underfunction
of the anterior pituitary) to help them grow. Also
known as somatropin, growth hormone.