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:
“I have hardly begun to live on Staten Island yet; but, like the man who, when forbidden to tread on English ground, carried Scottish ground in his boots, I carry Concord ground in my boots and in my hat,—and am I not made of Concord dust? I cannot realize that it is the roar of the sea I hear now, and not the wind in Walden woods. I find more of Concord, after all, in the prospect of the sea, beyond Sandy Hook, than in the fields and woods.”
—Henry David Thoreau (1817–1862)
“We are nothing but ceremony; ceremony carries us away, and we leave the substance of things; we hang on to the branches and abandon the trunk and body.”
—Michel de Montaigne (1533–1592)