- 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.
- 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 of ZAP-70 expression appears restricted to T-cell […]
- Zebra
‘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.
- Zygotic lethal gene
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 […]
- Zygote intrafallopian transfer (ZIFT)
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 […]
- Muscle, piriformis
A muscle that begins at the front surface of the sacrum (the V-shaped bone between the buttocks, at the base of the spine) and passes through the greater sciatic notch to attach to the top of the thighbone (femur) at its bony prominence (the greater trochanter). The gluteus maximus muscle covers the piriformis muscle in […]
- Cafe au lait spot
Cafe au lait spot: A flat spot on the skin that is the color of coffee with milk (café au lait) in persons with light skin, or a darker appearance (café noir) than the surrounding skin in persons with dark skin. About 10% of the general population have cafe au lait spots. Café au lait […]
- Syndrome, locked-in
A neurological disorder characterized by complete paralysis of voluntary muscles in all parts of the body except for those that control eye movement. The locked-in syndrome is usually a complication of a cerebrovascular accident (a stroke) in the base of the pons in the brainstem. The patient is alert and fully conscious but cannot move. […]
- Cerebrovascular accident (CVA) prevention
In many cases, a person may have a transient ischemic attack (TIA), a neurological event with the symptoms of a stroke, but the symptoms go away within a short period of time. This is often caused by the narrowing or ulceration of the carotid arteries (the major arteries in the neck that supply blood to […]
- Bacteremia
Bacteremia: The presence of live bacteria in the bloodstream. Bacteremia is analogous to viremia (the presence of a virus in the blood) and parasitemia (the presence of a parasite in the blood). Bacteremia, viremia and parasitemia are all forms of sepsis (bloodstream infection). The term “bacteremia” was compounded from “bacteria” and “-emia” (in the blood). […]