Dictionary

Nonoxynol-9 A potent spermicide (spermkilling agent) used as a contraceptive.

nonmelanoma skin cancer Skin cancer that does not involve melanocytes. Basal cell cancer and squamous cell cancer are examples of nonmelanoma skin cancers.

non-Hodgkin’s lymphoma See lymphoma, non-Hodgkin’s.

nongonococcal urethritis An inflammation of the urethra due to infections other than gonorrhea. Abbreviated NGU. NGU is far more common in men than in women and is transmitted by sexual intercourse. Chlamydia trachomatis is the organism most commonly responsible for NGU, but a number of different organisms can be the cause of NGU.

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.

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.

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.

nodular Bumpy.

node, sinus See sinoatrial node.

node, sinoatrial See sinoatrial node.

node, sentinel lymph See lymph node, sentinel.

node, SA See sinoatrial node.