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1. physical material having form and weight under ordinary conditions; called also substance.
gray matter areas of the nervous system where the nerve fibers are unmyelinated (not enveloped by a myelin sheath); it contains the bodies of the nerve cells. Tissue composed of myelinated fibers is called white matter. The cerebral cortex is entirely composed of gray matter and the cerebellum also contains some deep-seated masses of it. The spinal cord has a central core of gray matter surrounded by white matter; in cross section, its gray matter is shaped approximately like the letter H. Called also substantia grisea and gray substance.
[L. substantia, essence, material, fr. sub- sto, to stand under, be present]
1. substance; anything that occupies space.
gray matter substantia grisea.
white matter substantia alba.
1. A specific type of substance.
2. Discharge or waste, such as pus or feces, from a living organism.
Etymology: L, materia
1 anything that has mass and occupies space.
2 any substance not otherwise identified as to its constituents, such as gray matter, pus, or serum exuding from a wound.
Material substance that occupies cavities.
Material substance that occupies space.
matterAnatomy Stuff that occupies cavities. See Gray matter, White matter.
[L. substantia, essence, material, fr. sub-sto, to stand under, be present]
matterthat which constitutes the substance of physical forms, has mass, occupies space and can be quantified.
1. physical material having form and weight under ordinary conditions of gravity.
matter of the central nervous system, which represents the aggregations of the nerve cells.
matter of the central nervous system, which comprises the axons of the nerve cells.