Embryology of fascia

During the embryonic development of higher animals (from flat worms to humans, in the beginning we all look the same), three primary layers of cells forms, germ layers, which give rise to all tissues and organs in the animal. The three layers are called ectoderm, mesoderm and endoderm (see below) and it is the mesoderm which is the origin of fascia, skeletal, cartilage and muscle, all components which are associated with locomotion. More primitive animals have only one or two germ layers, they are lacking in mesoderm. When the human embryo is about two to three weeks old, the fascia begins to form from the mesoderm. The three germ layers are;

  • Ectoderm – The outer (ecto) layer, form the outer skin, hair and nails, the nervous system, ectochrine glands and the dentin and tooth enamel.
  • Mesoderm – The middle layer, form the fascia. This layer also forms all kind of muscles (skeletal, smooth and cardiac), bone tissue, cartilage, dermis and hypodermis, circulatory system, blood cells, lymphatic system, spleen, mesentery, adipose tissue, notochord, meninges (membranes of the brain and spinal cord), urogenital system, kidneys and more.
  • Endoderm – The inner layer, form the epithelial inner layer of the whole digestive tract, glands like liver and pancreas, respiratory system, bladder, thyroid and thymus.

First to develop from the mesoderm is the mesenchyme, an embryonic connective tissue. It consists of stellate cells with long spurs, with which they communicate with each other. The extra cellular matrix (ECM), between these cells, is a light fluid with thin embryonic fibers of collagen type III. Most of this ECM fluid consists of hyaluronan and water.

Some research wants to claim that the fascia can be found in the ectoderm (van der Wal, 2009). Recent research has also found a fascial link between fascial fibers of muscles in the poll, sensory nerves and the dura mater (the outer of the meninges), called the myodural bridge (Hack et al, 1995), (Scali et al, 2011, 2013, 2015), (Zheng et al, 2014, 2018). The same connection has now been found in horses and several other mammals, as well as in chickens and reptiles (Elbrønd & Schultz, 2019), (Zheng et al, 2017), (Dou et al, 2019), (Zhang et al, 2016). More about this in another item.

Fascia Anatomy & Physiology

Hyaluronan

Hyaluronan has a number of important physiological functions in our body and is critical for the slide and glide effects between muscle fibers and fascial sublayers. Therefore, it greatly affects our ability to move in balance and it helps maintain tissue homeostasis.

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Extracellular Matrix (ECM)

The extracellular matrix (ECM) is a scaffold where the cells exist. It mainly consists of fiber proteins and a fluid part, the ground substance.

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Embryology of fascia

During the embryonic development, three primary layers of cells forms, which give rise to all tissues and organs. One of them is the origin of fascia, skeletal, cartilage and muscle, all components which are associated with locomotion.

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What is fascia – in detail

Our entire body, all tissues, consists of cells and the substance that exists outside, around the cells, that is the extracellular matrix. With these explanations of fascia you understand how important it is to see the body as a whole and not part by part.

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Collagen

Collagen is the most abundant protein in the body, about 30% of our body protein. Next to water, collagen is the most common component of connective tissue.

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The components in fascia

The body consists of cells and the matrix outside, between the cells, the extracellular matrix (ECM). Fascia is the ECM and the cells maintaining the ECM. In this article the components of the Fascia are listed and explained.

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