In connective tissue, ground substance is the non-cellular components of extracellular matrix which contain the fibers.
It is usually not visible on slides, because it is removed during the preparation process.
Cells are surrounded by extracellular matrix in tissues, which acts as a support for the cells. Ground substance traditionally does not include collagen but does include all the other proteinaceous components, including proteoglycans, matrix proteins and, most prevalent, water. The non-collagenous components of extracellular matrix will vary depending on the tissue in which it is found.
Ground substance is amorphous, gel-like, and is primarily composed of glycosaminoglycans (most notably hyaluronan), proteoglycans, and glycoproteins.
The meaning of the term has evolved over time.
Famous quotes containing the words ground and/or substance:
“The thing that made me more and more afraid
Was that we’d ground it sharp and hadn’t known,
And now were only wasting precious blade.”
—Robert Frost (1874–1963)
“All the old supports going, gone, this man reaches out a hand to steady himself on a ledge of rough brick that is warm in the sun: his hand feeds him messages of solidity, but his mind messages of destruction, for this breathing substance, made of earth, will be a dance of atoms, he knows it, his intelligence tells him so: there will soon be war, he is in the middle of war, where he stands will be a waste, mounds of rubble, and this solid earthy substance will be a film of dust on ruins.”
—Doris Lessing (b. 1919)