Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «D»:
Disorder, specific developmental
Disorder, specific developmental: A
disorder that selectively affects one area of development, sparing essentially all other areas of development.
For example, dysgraphia is one type of specific developmental disorder. In dysgraphia there is inability to write legibly. Problems in dysgraphia may...
Disordered thinking: A failure to be able to "think straight." Thoughts may come and go rapidly. The person may not be able to concentrate on one thought for very long and may be easily distracted, unable to focus attention. The person may be unable to connect thoughts into logical sequences, with t...
Disorders, lymphoproliferative: Malignant
diseases of the lymphoid cells
and cells from the reticuloendothelial system (which take
up and sequester inert particles). The lymphoproliferative
disorders are in contrast to the myeloproliferative
disorders which are malignancies of certain bone marr...
Malignant diseases of certain bone marrow cells including those that give rise to the red blood cells, the granulocytes (types of white blood cells), and the platelets (crucial to blood clotting).
The myeloproliferative disorders include myelophthisic anemia, erythrobl...
Disruption sequence: The events that occur when a fetus that is
developing normally is subjected to a destructive agent such as the rubella (German
measles) virus. ...
Dissect: To cut apart or separate tissue as, for example, for anatomical study or in surgery. Also, an artery is said to dissect when its wall is torn, as in a dissecting aneurysm....
Dissecting aneurysm: A localized
widening (dilatation) of an artery (an aneurysm) in which
the wall of an artery rips (dissects) longitudinally. This
occurs because bleeding into the weakened wall splits the
wall. Dissecting aneurysms tend to affect the thoracic
aorta. They are particularly a...
Dissection: The process of cutting apart or separating tissue as, for example, in the study of anatomy or in the course of a surgical procedure....
Dissection, aortic: See: Aortic dissection....
Dissection, axillary: Surgery in which the axilla (the armpit) is opened -- to "dissect" means to "cut apart" -- in order to identify, examine, and sometimes remove structures such as lymph nodes or other tissue for diagnosis or treatment....
Dissection, neck: Surgery in which the neck is opened -- to "dissect" means to "cut apart" -- in order to identify, examine, and sometimes remove structures such as lymph nodes or other tissue for diagnosis or treatment.
A radical neck dissection involves removal of a tumor from the neck with an ad...
Dissection, radical neck
Dissection, radical neck: See: Radical neck dissection....
Disseminated sclerosis: See: Multiple sclerosis....
Disseminated vaccinia: See Progressive vaccinia....
Dissociation: In psychology and psychiatry, a perceived detachment of the mind from the emotional state or even from the body. Dissociation is characterized by a sense of the world as a dreamlike or unreal place and may be accompanied by poor memory of the specific events, which in severe form is kn...