My book consists of following lines."The interstitial fluid is entrapped in minute space among proteoglycan filaments. This combination of proteoglycan filaments and the fluid entrapped within them has a characteristic of gel so called tissue gel. Instead of flowing interstitial fluid mainly diffuses through gel. This diffuion allows rapid transport of interstitium of water nutrients,oxygen,cell excreta e.t.c. I can't get the meaning of these lines. I tried to search on net but didn't get a satisfactory explanation. Please explain this to me.
In the question, "tissue gel" clearly refers to "proteoglycan filaments and the fluid entrapped within them" and which appears in the interstitial space.
This is the same as what the Wikipedia article says about Extracellular matrix:
Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. (Source: Essential cell biology, 2004)
A.C, Guyton et al from University of Mississippi School of Medicine, 1973 also says the same:
Though 1/6 of most tissues is composed of interstitial fluid, this fluid is generally held tightly in place in the form of a gel. The reticulum of this gel is composed mainly of hyaluronic acid, but this is cross-linked slightly with collagen fibers to form a meshwork in which the interstitial fluids are trapped. The presence of this gel reduces the mobility of fluid in the tissues...
The exact term "tissue gel" is very rarely used in biology or histology, though.
You are probably confused because of this sentence, which is messed up: "This diffusion allows rapid transport
of interstitium of water, nutrients, oxygen, cell excreta e.t.c. " It should be: "This diffusion allows rapid transport of water nutrients, oxygen, cell excreta e.t.c. through the interstitium."