So what forms human connective tissue?
From bone through to blood, with cartilage, ligaments, periosteum, tendons, muscle, loose areolar and adipose tissue as the markers on the way – we make artificial categorisations, to highlight variations, but in reality, these things are more alike than they are different.
Connective tissue is a composite, and like artificial composites like reinforced concrete and glass fibre, combines the qualities of its components.
– The dense connective tissue that gets called Fascia is made up of· fibres of collagen, elastin and reticulin, laid randomly, which individually have varying elasticity, but together build a chaotic web of great flexibility and resilience. It is with movement that this chaos is made structurally useful, because movement will promote build up of fibres in the lines of weakness, and tearing down the fibres in lines of stress. The mechanism for this, again is not well researched.
– Ground substance – a colloid of many water-soluble carbohydrates (“GAGs”), some with proteins added, which can trap up to 1000 times their mass of water, and which can nourish cells and restrict the spread of oxidants and bacteria. Vitamin C, it is now believed, helps reduce the spread of infection by making the ground substance more resilient to pathogens. This ground substance acts as a “spacer” in the composite that is fascia, so the fibres are not pressed too compact against each other and bind, forming fibrous adhesions. As people age, and if they don’t look after themselves (not enough movement, use of poisons like cocaine) the ground substance loses these GAGs and becomes less hydrated. It becomes less able to nourish the other cells of the body, and fibres stick together more easily (building fibrosis).
– Cells, mostly fibrocytes, which make the fibres AND the ground substance. Most fluids in the body are derived from blood plasma, but not the ground substance! Look after your fibrocytes! They keep you well oiled and in shape! When there is injury, fibrocytes release actin filaments (the contractile protein in muscle), which attach to fibres and retract, pulling tissue together. That is how wounds close.
So the template for your body is made of randomly placed fibres in a thick soup!