S–T

satiety The sensation of fullness and satisfaction
after eating a meal. Satiety represents a conver-
gence of physical, physiologic, and emotional fac-
tors. The physical sensation of fullness occurs
when enough food fills the STOMACHto stretch its
walls. The stretching activates NERVEand HORMONE
sensors that then send physiologic signals to the
APPETITEand satiety centers in the BRAINand to
receptors in the SMALL INTESTINEand the HUNGER
center in the HYPOTHALAMUS. These signals slow or
stop the release of hormones and neurotransmit-
ters necessary for digestion and initiate the release
of other hormones and biochemicals that have
roles in absorbing NUTRIENTSinto the BLOODcircula-
tion and further METABOLISMof those nutrients.
Research indicates that foods high in protein
result in reaching physical satiety the most rapidly.
Foods high in fat take much longer to trigger
physical satiety. These findings imply that eating
the proteins in a meal first, such as meats or
legumes, may curb the appetite, whereas eating
the fats or carbohydrates in a meal first may
extend appetite. Each circumstance has advan-
tages, depending on an individual’s health and
weight management situation.
The emotional component of satiety comes
when the meal has satisfied desires for certain
characteristics of food such as textures, flavors,
and quantity. Emotional satiety results in nerve
signals to pleasure receptors in the cerebral cortex
as well as to the brain’s appetite and satiety cen-
ters. This is the most variable factor of satiety,
influencing whether a person eats not enough or
too much. Emotional eating is a significant dimen-
sion of WEIGHT LOSS AND WEIGHT MANAGEMENT.
See also EATING HABITS; FOOD CRAVINGS; NEURO-
TRANSMITTER.

scurvy A health condition that results from

long-term deficiency of vitamin C (also called

ascorbic acid). Vitamin C is essential for the forma-

tion of collagen, a fibrous protein that is the foun-

dation for connective tissue throughout the body

and the framework for BONEtissue. Collagen is

integral to the walls of BLOODvessels. Collagen also

is an essential component of SCARtissue, necessary

for wound HEALING. Without vitamin C, a water-

soluble vitamin the diet must provide on a rela-

tively daily basis, the body cannot produce

collagen.

Symptoms and Diagnostic Path

The most common symptoms of scurvy are bleed-

ing gums and loose TEETH. Other symptoms

include low grade FEVER, extended or lack of

wound healing, PETECHIAE(pinpoint hemorrhages

beneath the SKIN), and internal hemorrhage. ANE-

MIAis often the indication that there is bleeding

somewhere in the body. The diagnostic path

includes blood tests to measure the amount of

ascorbic acid in the blood circulation as well as in

the white blood cells (leukocytes) along with a

careful PERSONAL HEALTH HISTORYthat includes infor-

mation about EATING HABITS.

Treatment Options and Outlook

Treatment for scurvy is vitamin C supplementa-

tion, which generally restores vitamin C levels and

eliminates symptoms after about a week of treat-

ment. In all but the most severe cases, scurvy is

completely curable. Doctors generally recommend

continued vitamin C supplementation to prevent

RECURRENCE. Because vitamin C is water-soluble,

there is no risk of toxicity with such prophylaxis.

Increasing dietary consumption of foods that con-

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