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*As with all anatomy I suggest you search for each new term on google then click on the ‘Images’ tab at the top of the page.  Look at as many different pictures of each structure, from as many different angles as you can.  Then look at it on the Visible Body. This will help you get a 3 dimensional image of the structure in your head.

The Membrane System is made up of three layers-

❍ Pia mater This is the innermost layer and it adheres to the surface of the brain and spinal cord.

❍ Arachnoid mater This is the middle layer and is close to the dura.

❍ Dura mater This is the outer most layer and is very tough. It is firmly attached to the bones of the skull, C2, C3, and S2. It is free floating around the rest of the spine.

These three sheaths of membrane are known collectively as the meninges.  They surround and enclose the central nervous system or brain and spinal cord.  The space between each layer is filled with cerebrospinal fluid.  The space between the arachnoid and dura mater is called the Sub arachnoid space. It is the Sub arachnoid space that contains the majority of the cerebrospinal fluid.
The Cranial Dura is further sub-divided into two layers.
The outer layer lines the inside of the cranuim and the inner layer forms several folds or infoldings called -

❍ The Falx Cerebri - A sickle-shaped membrane running from the front the to back of the cranium along the mid line between the two Cerebral hemispheres.

❍ The Falx Cerebelli – A much smaller sickle-shaped membrane passing down the midline of the Occipital region between the two Cerebellar hemispheres.

❍ The Tentorium Cerebelli - A tent-shaped membranous structure passing almost horizontally across the Cranium dividing the Cerebrum above from the Cerebellum below.

❍ The Diaphragma Sellae - A small horizontal membrane forming a roof over the Sella Turcica of the Sphenoid bone and enveloping the Pituitary Gland.

It is helpful to think of the Cranial Dura as being like a balloon with four infoldings inside.  Restrictions in this membrane can pull the cranial bones into compression and restrict areas of the brain.

As stated previously, but it is worth saying again, all parts of the Membrane system are interconnected forming a Reciprocal Tension Membrane System.  Meaning that tensions within any part of the Membrane System are liable to influence all other parts of the Membrane System.

<< Back to Basics 1 syllabus

<< Back to Basics 1 syllabus

*As with all anatomy I suggest you search for each new term on google then click on the ‘Images’ tab at the top of the page. Look at as many different pictures of each structure, from as many different angles as you can. Then look at it on the Visible Body. This will help you get a 3 dimensional image of the structure in your head.

The cranio sacral system is a physiological system within the body. Along with the Respiratory and Cardio-Vascular systems, it forms one of the three primary life systems.

The Cranio Sacral System consists of -
❍ Fluids
❍ Membranes
❍ Fascia
❍ Bones

Each is a recognised anatomical structure but outside Cranio Sacral Therapy they are not treated as one integrated system.

CEREBRO SPINAL FLUID

A clear colourless fluid which surrounds and bathes the central nervous system, creating the environment within which the brain and spinal cord grow, develop and function. It provides nutrition and drainage for the brain and spinal Cord also. It is in continuous motion, as any stagnation would undermine the brain and nervous
system.

Cerebro spinal Fluid is produced in hollow spaces at the centre of the brain called ventricles and circulates throughout the membrane system.

THE MEMBRANE SYSTEM

Containing the cerebrospinal fluid is a tough waterproof sack made up of three membranous layers called the meninges which surround the brain and spinal cord. The meninges have horizontal infoldings in the cranium which separate the cerebrum from the cerebellum called the Tentorium Cerebelli and a vertical infolding called the Falx Cerebri and Falx Cerebelli which divide the right and left hemispheres of the Cerebrum and cerebellum respectively.

THE FASCIA

Fascia is a connective tissue which forms a continuous sheath throughout the body from the top of the head to the soles of the feet. It envelops every organ, nerve, blood vessel, muscle and indeed every structure throughout the body.

This continuous fascial sheath forms a close connection to the meninges at the point where each peripheral nerve emanates from the spinal cord. As the spinal nerves penetrate the Dura they pull some of the Dura with them and this blends into the fascial sheath which covers the spinal nerve on its journey. This transition point from membrane to fascia is called the epineurium. It is one of the ways the Cranio Sacral Rhythm is translated to the rest of the body

BONES

The meninges are closely attached to the bones of the Cranium and also to the 2nd and 3rd Cervical Vertebrae (C2 and C3) and to the Sacrum and Coccyx. The outer layer of the Dura is so closely attached to the bones of the Cranium that it forms a periosteum or inner lining to these bones.

Consequently, all the bones to which the membranes attach must inevitably follow any motion exhibited by the membrane, expanding and contracting in accordance with the membrane and reflecting every pull or tension within the membrane system.

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