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.

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 of ZAP-70 expression appears restricted to T-cell […]

‘When you hear hoof beats, think of horses, not zebras.’ For example, when someone develops a mild transient cough, a virus infection is the most logical and likely cause, and tuberculosis is a zebra.

A gene that is lethal (fatal) for the zygote, the cell formed by the union of a sperm (male sex cell) and an ovum (female sex cell). The zygote would normally develop into an embryo, as instructed by the genetic material within the unified cell. However, a zygotic lethal gene scotches prenatal development at its […]

A technique in which a woman’s egg is fertilized outside the body, then implanted in one of her fallopian tubes. This technique is one of the methods used to overcome infertility, the inability of couples to produce offspring on their own. First, the egg and the male sperm needed to fertilize it are harvested. Then […]

Infection of the vagina by a fungus known as Candida, characteristically causing itching, burning, soreness, pain during intercourse and urination, and vaginal discharge. Yeast vaginitis occurs when new yeast are introduced into the vagina or there is an increase in the quantity of yeast in the vagina relative to the quantity of bacteria (as when […]

Dilation: The process of enlargement, stretching, or expansion. The word “dilatation” means the same thing. Both come from the Latin “dilatare” meaning “to enlarge or expand.”

Hypertensive; Normotensive.

Hereditary hemorrhagic telangiectasia.

Ageusia: An inability to taste sweet, sour, bitter, or salty substances. People who can taste sweet, sour, bitter, or salty substances but have a reduced ability to do so are said to have hypogeusia.