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Zinc: A mineral essential to the body. Zinc is a constituent of
many enzymes that permit chemical reactions to proceed at normal
rates. It is involved in the manufacture of protein (protein
synthesis) and in cell division. Zinc is also a constituent of
insulin and is concerned with the sense of smell. According to
the National Academy of Sciences, the Recommended Dietary
Allowances of zinc are 12 milligrams per day for women and 10
milligrams per day for men. Food sources of zinc include meat
including liver, eggs, seafood, nuts and cereal. Deficiency of
zinc is associated with short stature, anemia, increased
pigmentation of skin (hyperpigmentation), enlarged liver and
spleen (hepatosplenomegaly), impaired gonadal function (hypogonadism),
impaired wound healing, and immune deficiency. (For a genetic
disorder that impairs zinc uptake, please see Acrodermatitis
enteropathica). Too much zinc can cause gastrointestinal
irritation (upset stomach), interfere with copper absorption and
cause copper deficiency, and (like too little zinc) cause immune
deficiency. Recently, zinc has been touted as a treatment for
the common cold (see the MedicineNet NEWS).
Zinc deficiency: Deficiency of zinc is associated with short
stature, anemia, increased pigmentation of skin (hyperpigmentation),
enlarged liver and spleen (hepatosplenomegaly), impaired gonadal
function (hypogonadism), impaired wound healing, and immune
deficiency. (For a genetic disorder that impairs zinc uptake,
please see Acrodermatitis enteropathica). According to the
National Academy of Sciences, the Recommended Dietary Allowances
of zinc are 12 milligrams per day for women and 10 milligrams
per day for men. Food sources of zinc include meat including
liver, eggs, seafood, nuts and cereal.
Zinc deficiency dermatitis and diarrhea: A genetic disease
called acrodermatitis enteropathica is characterized by the
simultaneous occurrence of skin inflammation (dermatitis) and
diarrhea. The skin on the cheeks, elbows and knees and tissue
about the mouth and anus are inflammed. There is also balding of
the scalp, eyebrows and lashes, delayed wound healing and
recurrent bacterial and fungal infections due to immune
deficiency. The key laboratory finding is an abnormally low
blood zinc level reflecting impaired zinc uptake. Oral treatment
with zinc is curative.
Zinc excess: Too much zinc can cause gastrointestinal irritation
(upset stomach), interfere with copper absorption and cause
copper deficiency, and (like too little zinc) cause immune
deficiency. According to the National Academy of Sciences, the
Recommended Dietary Allowances of zinc are 12 milligrams per day
for women and 10 milligrams per day for men.
Zinsser: See Brill-Zinsser disease (recrudescent epidemic
typhus).
Zygoma: The bone that forms the prominence of the cheek. Known
also as the zygomatic bone, the zygomatic arch, malar bone, yoke
bone. Zygoma comes from the Greek zygon meaning a yoke (as for
oxen).
Zygomatic arch: See Zygoma.
Zygomatic bone. See Zygoma.
Zygote: A zygote is the cell that is formed by the union of a
sperm (male sex cell) and an ovum (female sex cell). The zygote
develops into the embryo as instructed by the genetic material
within the unified cell. The unification of a sperm and an ovum
is called "fertilization." (see sperm, ovum). |
Highlights
