Webster's New World Medical Dictionary

SAD
Seasonal affective disorder.
safe sex
Sexual practices that do not involve the
exchange of bodily fluids, including blood, sperm,
vaginal secretions, and saliva, to avoid AIDS and
other sexually transmitted diseases. The term safe
sex is generally used to mean sex without penetra-
tion or sex using condoms or other barrier meas-
ures with consistency. 
sagittal
A vertical plane passing through the
standing body from front to back. The median plane
that splits the body into left and right halves. See
also Appendix B, “Anatomic Orientation Terms.”
sagittal sinus
A large vein that runs on the top of
the skull from front to back and then splits to carry
blood from the brain toward the heart.
saline 1
Relating to salt (sodium chloride).
2
Salty, containing salt.
3
A salt solution, often
adjusted to the normal salinity of the human body.
Saline solutions are commonly used in medicine as
fluid replacements to treat or prevent dehydration.
Certain concentrations of both sodium and chloride
in the blood are essential for normal body functions.
salivary gland
A gland in the mouth that pro-
duces saliva. The salivary glands can become
inflamed, as in Sjogren’s syndrome and mumps.
Salk vaccine
See 
polio vaccine, inactivated.
salmon patch
A small flat patch of pink or red
(salmon-colored) skin, most commonly found on
the forehead between the eyebrows (called an
angel’s kiss), on the eyelids, or on the nape of the
neck (called a stork bite). Salmon patches are seen
in 30 to 40 percent of newborns and are usually
most noticeable when the baby cries. A salmon
patch is a collection of capillaries. Salmon patches
are of no consequence and tend to disappear in
time. Also known as nevus simplex, stork bite.
Salmonella
A group of bacteria that causes
typhoid fever and other illnesses, including food
poisoning, gastroenteritis, and enteric fever from
contaminated food products. See also 
food poison-
ing; Salmonellosis.
salmonellosis
Infection with bacteria belonging
to the genus Salmonella. Salmonellosis is particu-
larly dangerous for people with immunodeficiency
diseases and sickle cell disease. Symptoms usually
begin within 12 to 24 hours after exposure and may
include stomach cramps, diarrhea, fever, and some-
times vomiting. Diagnosis can be confirmed via
examination of a stool sample for Salmonella bacte-
ria. Most people exposed to Salmonella feel fine
within a few days and do not require treatment
other than extra fluids. Some need antibiotics, and a
few need hospitalization. See also 
food poisoning.