Select Page

Archives: Dictionary

Keiths bundle

The bundle of cardiac muscles beginning at the trunk of the atrioventricular node, passing through the right atrioventricular fibrous ring, then, extends to the membranous portion of the interventricular septum. Its function involves electrical conduction, transmitting the electrical impulses from the atrioventricular node to the apex of the fascicular branches. ( Syn: atrioventricular bundle, AV bundle, fasciculus atrioventricularis, atrioventricular band, gaskells bridge, His band, His bundle, Kents bundle, Kent-His bundle,...

Read More

Kell Antigen System

A group of antigens on the human red blood cell surface which are important determinants of blood type and are targets for autoimmune or alloimmune diseases which destroy red blood cells. Kell can be noted as K, k, or Kp. The Kell antigens are peptides found within the Kell protein, a 93 kilodalton transmembrane zinc-dependent endopeptidase which is responsible for cleaving endothelin-3. ( Syn: Kell-Cellano...

Read More

Kell Blood Group

The Kell blood group system is complex and contains many antigens that are highly immunogenic. These antigens are the third most potent, after those of the ABO and Rh blood groups, at triggering an immune reaction. Antibodies that target Kell antigens can cause transfusion reactions and hemolytic disease of the newborn (HDN). In the case of HDN, ABO and Rh incompatibility are more common causes. However, disease caused by maternal anti-ABO tends to be mild, and disease caused by maternal anti-Rh can largely be prevented. The infrequent cases of HDN caused by Kell immunization tend to result in severe fetal anemia because maternal anti-Kell target fetal red blood cell (RBC) precursors, suppressing the fetal production of RBCs. (Blood Groups and Red Cell Antigens, Chapter 8: The Kell blood group,

Read More

Kelvin Scale

1. An absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. ( 2. A scale for measuring temperature, with zero defined as absolute zero, with kelvins as the units (equivalent to degrees Celsius). ( 3. A temperature scale that defines absolute zero as 0 degrees; water freezes at 273.16 degrees and boils at 373.16 degrees....

Read More


Noun 1. A family of fibrous structural proteins. Keratin is the key structural material making up the outer layer of human skin. It is also the key structural component of hair and nails. ( 2. A fibrous scleroprotein that occurs in the outer layer of the skin and in horny tissues such as hair, feathers, nails, and hooves. ( Word origin: From Greek keras (genitive keratos) “horn” + chemical suffix -in usually indicating a neutral substance, antibiotic, vitamin, or...

Read More

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how