Library · Histology
Articular cartilage
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Articular cartilage is the layer that coats the bone right at the surface where a joint moves.
It has one peculiarity: very few capillaries reach it, and capillaries are the finest blood vessels. Its own cells, the chondrocytes, therefore live with little oxygen, and to get energy they burn glucose without oxygen, through a pathway called anaerobic glycolysis, which leaves lactic acid as waste.
If there is no plumbing, how do they eat? Two ways. One is diffusion, the slow passage of substances through the tissue itself. The other is a pumping action: the cartilage is compressed and released over and over, and that squeeze pushes nutrients inward. It is a sponge with no plumbing of its own that fills up every time someone steps on it.
That is why cartilage cannot be very thick: those two routes only reach so far.
In brief
Articular cartilage is the layer that covers bone at the joint surface, and it has very few capillaries.
Its chondrocytes work with little oxygen and get their energy from glucose through anaerobic glycolysis, leaving lactic acid behind.
Nutrients arrive in two ways: by diffusion and by the pumping action of compressing and releasing the cartilage.
A sponge with no plumbing of its own that fills up every time someone steps on it.
Those two routes set a limit on how thick cartilage can get.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingHistology, Chondrocytes, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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