Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «Z»:
Z chromosome: A sex chromosome in certain animals,
such as chickens, turkeys, and moths. In humans, males are XY and
females XX, but in animals with a Z chromosome, males are ZZ and
females are WZ....
Zaleplon: Brand name: Sonata. A sedative hypnotic drug in a class closely related the benzodiazepines, affecting the central nervous system, used as a sleep drug. For more information, see: zaleplon....
ZAP-70: Zeta-chain-associated protein kinase 70. A member of the protein tyrosine kinase family, ZAP-70 is normally expressed in T cells and natural killer cells and has a critical role in the initiation of T-cell signaling. ZAP-70 is expressed in T cells and tumors of T-cell lineage. A high level o...
Zebra: The term "zebra" in medicine does not refer to the striped African animal but to an unlikely diagnostic possibility. It comes from an old saying in teaching medical students about how to think logically in regard to the differential diagnosis: "When you hear hoof beats, think of horses, not z...
Zeitgeber: An environmental
agent or event that provides the cue for setting or resetting a biological clock. To be synchronized with our environment,
we need the input of Zeitgebers. The most important Zeitgeber in nature is light. Social factors, chemical factors and activity can also serve as Z...
Zellweger syndrome: A genetic disorder, also called the cerebrohepatorenal syndrome, characterized by the reduction or absence of peroxisomes (cell structures that rid the body of toxic substances) in the cells of the liver, kidneys, and brain. Zellweger syndrome is one of a group of disorders calle...
Zenker diverticulum: The most common
type of outpouching in the esophagus, due to increased pressure causing the mucous membrane of the esophagus to herniate through a defect in the wall of esophagus. Zenker diverticuli are usually located in the posterior hypopharyngeal wall. Small Zenker divertic...
Zenker's diverticulum: See: Zenker diverticulum....
Zhitai: One of the three major preparations of red yeast rice, a tradition Chinese medicine now used to lower cholesterol....
Zhong Wei Chen
Zhong Wei Chen: See: Chen, Zhong Wei....
Zidovudine: See: AZT....
Zidovudine triphosphate: The active form of zidovudine which is also known as AZT. See: AZT....
ZIFT: Stands for zygote intrafallopian transfer, a method
used to treat infertility in which an egg fertilized in vitro
(outside the body) is placed into a woman's fallopian tube.
This technique is one used to overcome infertility, the inability of
couples to produce offspring on their own.
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...
Zinc acetate: A form of zinc that has been used
as an emetic....