Dictionary

node A knot, a collection of tissue. For example, a lymph node is a collection of lymphoid tissue. See also nodule.

node, atrioventricular See atrioventricular node.

node, AV See atrioventricular node.

node, Heberden’s See Heberden’s node.

node, SA See sinoatrial node.

node, sentinel lymph See lymph node, sentinel.

node, sinoatrial See sinoatrial node.

node, sinus See sinoatrial node.

nodular Bumpy.

nodule A small collection of tissue that is palpable (can be felt) at any level of the skin (in the epidermis, dermis, or subcutis) or in another tissue of the body. Nodules characteristically range in size from 1 to 2 cm in diameter.

noncompliance Failure or refusal to comply. In medicine, the term noncompliance is commonly used in regard to a patient who does not take a prescribed medication or follow a prescribed course of treatment. A person who demonstrates noncompliance is said to be noncompliant.

nondisjunction Failure of paired chromosomes to separate (to disjoin) during cell division, so that both chromosomes go to one daughter cell and none go to the other. Nondisjunction causes errors in chromosome number, such as trisomy 21 (Down syndrome) and monosomy X (Turner syndrome). It is also a common cause of early spontaneous abortions.