Bone is Fascia. Discuss!
When is a door not a door? When it’s a jar.
There has been a lot of activity on Facebook recently, with John Sharkey stating that bone is fascia. I have a problem with this in a couple of ways. Firstly because it’s not a discussion point that is being raised, but a statement. BONE IS FASCIA.
This statement of fact doesn’t leave anyone with any option except to agree or disagree and creates a polarisation that I find uncomfortable and unhelpful.
Instead of a reasoned argument that follows a hypothesis, we are instead faced with a crowd of people in a video, chanting “bone is fascia, bone is fascia”, as if saying something factually questionable over and over again makes it true.
So let’s ask the question and discuss the possibilities, raise some relevant points and let the reader make up their own mind.
Before I dive in here, this kind of discussion/argument, whilst reasonable and vital in a scientific forum, has the tendency to be seen as confrontational when addressed to a more ‘touchy feely’ audience. So please let me state that none of this is about personality or personal enmity. I like John Sharkey and have an enormous amount of respect and time for him. That I disagree with him and feel able to do so publicly is a mark of that respect.
Here is a picture of a railway track.
Here is a picture of a road.
They are different things, but have some elements in common. They are both surfaces for transport and the things that travel on them have wheels. They both convey people from one place to another. There are different gauges of railway and sizes of trains. The railway track can carry different types of trains at different speeds to different places. The road can support different types of vehicles and there are different types of road, road surface and classification.
However even though they have things in common a railway track is not a road and a road is not a railway track and confusing the two would be both unwise and potentially dangerous.
Now I’ve rather laboured that comparison, let’s talk about bone and fascia. They are both connective tissues, and have things in common. Lots of collagen for one. There are two types of bone, cancellous (or trabecular) and cortical, that do different things and have different purposes and functions.
If as John suggests, bone is just “starched fascia” then “starched fascia” should be able to do the job of bone. Let’s reverse the bone is fascia statement, say that fascia is bone and see how it stands up.
If it were true, it should be able to have the cells within it to allow it to regulate calcium levels in the body, which lets face it is one of the more important jobs that bone has. It should be able to store calcium. Yet 97% of the calcium reserves in the body are in bone. Original osteoblasts get trapped in newly forming bone and mature into osteocytes which cannot divide further.
Osteocytes stay in contact with each other in the bone via gap junction and maintain the integrity of bone by releasing calcium ions which then get incorporated in to bone tissue. Fascia does not have this capacity. Bone contains about 33% collagen and 39% calcium. The remainder is made up of phosphate, carbonate and other mineral salts.
Collagen allows bone to bend slightly and resist stretching forces. Without collagen bone would be too brittle and without mineral salts, bone would be too rubbery. For fascia to be bone, the starched fascia should have a balance of both collagen and calcium and contain heamapoetic stem cells within its structure that would then give rise to red blood cells. No prizes for guessing that it doesn’t.
If fascia were bone, then it would receive signals from the parathyroid gland when there was a fall in calcium levels in the blood and would be able to release calcium from its starchy insides to balance out blood calcium levels.
The list is pretty endless in terms of the differences, and this is why bone has its own classification as a connective tissue, along with cartilage, blood and proper (within which the stuff we refer to as fascia has several entries). The classifications of connective tissues may not be very extensive and certainly there is a lot of tissue that is poorly described and understood. Much more work is needed to expand some of the tissues that are only given a few words in anatomy books. Bone however is not one of these tissues.
Connective tissue is mostly inert, meaning that it is mostly made up of non-cellular material. That doesn’t mean that connective tissue doesn’t have any cells, but that it mostly isn’t cellular. The non cellular stuff in connective tissue is however as important and interesting as the cells that are there and components within the extra cellular (ie non cellular) matrix are infinitely interesting and important. The clue is in the name extra cellular.
In blood plasma for instance, there is a range of elements vital for every breath we take and every move we make; yet plasma is essentially a non-cellular connective tissue. Please bear in mind that none of this is my opinion, just that boring old stuff we call science and fact.
So is bone fascia? Is a railway a road? Having things in common doesn’t make them the same.