Glossary of Terms


Neuroglial cell of ectodermal origin, characterized by fibrous, protpplasmic, or plasmatofibrous processes. Collectively, such cells are astroglia. Fibrous a’s, astrocytes found mainly in the white matter of the brain, having long, thin, infrequently branched cytoplasmic processes containing numerous fibrillar structures. Gemistocytic a., gemistocyte. Plasmatofibrous a’s, astrocytes found at the junction of the gray and white matter of the brain; the cytoplasmic processes extending into the white matter are fibrous and those extending into the gray matter are protoplasmic. Protoplasmic a’s, astrocytes found mainly in the gray matter of the brain, having many branching, thick cytoplasmic processes. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 160.)

In anatomy, the first cervical vertebra, which articulates above with the occipital bone and below with the axis. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 163.)


In biomedical engineering, bioimpedance is a term used to describe the response of a living organism to an externally applied electric current. It is a measure of the oppostion to the flow of that electric current through the tissues, the opposite of electrical conductivity. The measurement of the bioimpedance (or bioelectrical impedance) of the humans and animals has proved useful as a non-invasive method for measuring such things as blood flow (often referred to as bioimpedance plethysmography) and body composition ( known as bioelectrical impedance analysis or simply BIA). (


Cardiac Cycle
A complete cardiac movement or heart beat. The period from the beginning of one heart beat to the beginning of the next; the systolic and diastolic movement, with the interval between them. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 416)

Central Nervous System
Pertaining to the brain, cranial nerves and spinal cord. It does not include peripheral nerves.

Cerebrospinal Fluid
The fluid that flows through and protects the 4 cavities (ventricles) of the brain, the spinal cord’s central canal, and the space (known as the subarachnoid space) between the middle and inner layers of the membrane (meninges) enclosing the brain and spinal cord. Osteopathy’s founder, Dr. A.T. Still referred to this fluid as “the highest known element.”

It is thought that the cerebrospinal fluid fluctuates, rather than circulates, in a rhythmic cycle of reciprocating activity. There is much in scientific litera¬ture to corroborate such a two phase cycle or tide like phenomenon.

This regular fluctuation of the cerebrospinal fluid may be found on palpation of the cranium, with skillful and intelligent fingers, as a rhythmic impulse that in the normal healthy adult has a rate averaging 12.47 cycles per minute. Finding it requires rather delicate tactile perception.

By using the membranous articular mechanism it is possible to manually alter the rate, amplitude and/or direction of this fluctu¬ant wave. Methods of changing the rate and amplitude are described as accelerative, incitant, retardative and repressant; the direction, anteroposterior or longitudinal and lateral; with specific focusing of the fluctuant wave upon a lesioned area, as “directing the tide.”

Because of the profound therapeutic effects thereby obtained, hydrodynamically in relation to the interstitial fluids of the body by way of the lymphatics, as well as in biochemical and bio¬electrical potentials, the term “potency” of the cerebrospinal fluid has been used. (Glossary of Terms Relating to Osteopathy in the Cranial Field Produced under the auspices of The Sutherland Cranial Teaching Foundation Edited by Harold I. Magoun, A.B., D.O., M.Sc.(Hon.), First Edition, 1961)

Choroid Plexus
An area on the ventricles of the brain where cerebrospinal fluid (CSF) is produced by modified ependymal cells. Choroid plexus is present in all components of the ventricular system except for the cerebral aqueduct and the occipital and frontal horns of the lateral ventricles. It is found in the superior part of the inferior horn of the lateral ventricles. It follows up along this boundary, continuous with the inferior of the body of the lateral ventricles. It passes into the interventricular foramen, and is present at the top of the third ventricle. There is also choroid plexus on the fourth ventricle, on the section closest to the bottom half of the cerebellum. (

The outer layer of an organ or other body structure, as distinguished from the internal substance. Cerebelar c., c. cerebelli, c of cerebellum, the superficial gray matter of the cerebellum; calledf also substantia corticalis cerebelli and cortical substance of cerebellum. Cerebral c., c. cerebri, c. of cerebrum, the thin layer of mantle of gray substance covering the surface of each cerebral hemisphere, folded into gyri that are separated by sulci. It reaches its highest development in man, in whom it is responsible for the higher mental functions, for general movement, for visceral functions, perception, and behavioual functions. Called also pallium. Many clasifications have been suggeted: it has been divided into archeocortex, paleocortex, and neocortex according to supposed phylogenetic and ontogenetic differences; into areas according to the presence of six cell layers or acording to differences in the structure and arrangement of cell and fiber layers; and into functional areas, such as motor, sensory, and association area. According to official anatomical nomemclature, the cerebral cortex has six layers, situated from the surface inward: I, lamina molecularis; II, lamina granularis externa; III, lamina pyramidalis externa; IV, lamina granularis interna; V, lamina pyramidalis interna; VI, lamina multiformis. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 386.)

Cranial Bone Strain Patterns
Any of several sub-optimal movement patterns of the cranial bones resulting from some degree of trauma, and which cause and indicate strain within the system.

Cranial Osteopathy
Link: Osteopathy in the Cranial Field

Cranial Vault
Those bones of the skull enclosing the brain, as distinguished from the bones of the face. Synonym: braincase, cranial vault, cranium cerebrale, cerebral cranium. (


Dural Membrane / Dural Mater

The outer most, toughest, and most fibrous of the three membranes covering the brain and spinal cord; called also pachymeninx. D. m. of brain, d.m. encephali, the dura mater covering the brain, composed of two mostly fused layers: an endosteal outer layer (endocranium) adherent to the inner aspect of the cranial bones, and an inner, meningeal layer. Venous sinuses and the trigeminal ganglion are located between the layers. D.m. of spinal core, d.m. spinalis, the dura mater covering the spinal cord; it is separated from the perioseum of the enclosing vertebrae by an epidural space containing blood vessels and fibrous and areolar tissue. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 514.)


Gastrointestinal Disorders
Disorders of the Gastrointestinal system, such as colic, gastroesphageal-reflux (GERD), constipation, and diarrhea

Glial Cell / Neuroglial Cell

The central nervous system consists of neurons and glial cells. Neurons constitue about half the volume of the CNS and glial cells make up the rest. Glial cells provide support and protection for neurons. They are thus known as the “supporting cells” of the nervous system. The four main functions of glial cells are: to surround neurons and hold them in place, to supply nutrients and oxygen to neurons, to insulate one neuron from another, and to destroy and remove the carcasses of dead neurons (clean up). The three types of CNS supporting cells are Astrocytes, Oligodendrocytes, and Microglia. The supporting cells of the PNS are known as Schwann Cells. (


Intracranial Pressure
The pressure in the space between the skull and the brain, i.e., the pressure of the subarachnoidal fluid. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1353)


Laser Doppler Flowmetry
A flow measurement technology employing laser waves Link:


Mastoid Process
Process of the temporal bone behind the ear at the base of the skull

An acronym for “Magnetic Resonance Imaging.” A non-invasive method of obtaining images of internal soft bodily tissue such as the brain and the spinal cord through the use of powerful magnets and radio waves.


Pertaining to a nerve or to the nerves. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1126.)


Oligodendrocytes / Oligodendroglia
The non-neural cells of ectodermal origin forming part of the adventitial structure ( neuroglia) of the central nervous system; projections of the surface membrane of each of these cells (oligodendrocytes) fan out and coil around the axon of many neurons to form myelin sheaths in the white matter. With microglia, they form the perineuronal satellites in the gray matter. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1173.)

Osteopathic Manipulative Treatment (OMT)
The therapeutic application of manually guided forces by an osteopathic physician (US Usage) to improve physiologic function and/or support homeostasis that has been altered by somatic dysfunction. OMT employs a variety of techniques (Foundations of Osteopathic Medicine, 2nd ed., Lippincott, Williams & Wilkins, 2003) including:

    1. active method
    2. articular treatment
    3. balanced ligamentous tension
    4. combined method
    5. compression of the fourth ventricle
    6. counterstrain
    7. cranial treatment
    8. Dalrymple treatment
    9. direct method
    10. exaggeration method
    11. exaggeration technique
    12. facilitated positional release
    13. fascial release treatment
    14. fascial unwinding
    15. functional method
    16. Galbreath treatment
    17. hepatic pump
    18. indirect method
    19. inhibitory pressure technique
    20. integrated neuromusculoskeletal release
    21. ligamentous articular strain
    22. liver pump
    23. mandibular drainage
    24. mesenteric release
    25. muscle energy
    26. myofascial release
    27. myofascial technique
    28. myotension
    29. osteopathy in the cranial field
    30. passive method
    31. pedal pump
    32. percussion vibrator technique
    33. positional treatment
    34. progressive inhibition of neuromuscular structures
    35. range of motion technique
    36. soft tissue
    37. soft tissue technique
    38. Spencer technique
    39. splenic pump technique
    40. springing technique
    41. Still technique
    42. thoracic pump
    43. thrust treatment
    44. toggle technique
    45. traction treatment
    46. v-spread
    47. ventral techniques
    48. visceral manipulation

    Osteopathic Philosophy / Principles
    Link:  Philiosophy of Osteopathy

    Osteopathy in the Cranial Field
    Link:  Osteopathy in the Cranial Field


    The application of the fingers to the surface of the skin or other tissues, using varying amounts of pressure, to selectively determine the condition of the parts beneath (Foundations of Osteopathic Medicine, 2nd ed., Lippincott, Williams & Wilkins, 2003)

    Palpation for Motion
    The use of trained tactile sense to determine the presence or absence of that slight yielding which denotes the amount and character of cranial articular mobility.

    Palpation for Position
    The use of trained tactile sense to note the positional relationship of any given cranial bone to the adnexa, as a part of the systematized, diagnostic procedure in cranial osteo¬pathy. (Glossary of Terms Relating to Osteopathy in the Cranial Field Produced under the auspices of The Sutherland Cranial Teaching Foundation Edited by Harold I. Magoun, A.B., D.O., M.Sc.(Hon.), First Edition, 1961)

    The essential elements of an organ; used in anatomical nomenclature as a general term to designate the functinoal elements of an organ, as distinguished from its framework, or stroma. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg.1231.)

    The condition of being wide open. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1241.)

    Primary Respiratory Mechanism
    Link: Osteopathy in the Cranial Field


    The triangular bone just below the lumbar vertebrae, formed usually by five fused vertebrae (sacral vertebrae) that are wedged dorsally between the two hip bones; called also os sacrum. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1479.)

    Sagittal Suture
    The sagittal suture is a dense, fibrous connective tissue joint between the two parietal bones of the skull. At birth, the bones of the skull do not meet. If certain bones of the skull grow too fast then “premature closure” of the sutures may occur. This can result in skull deformities. If the sagittal suture closes early the skull becomes long, narrow, and wedge-shaped, a condition called “scaphocephaly.” Two anatomical landmarks are found on the sagittal suture: the bregma and the vertex of the skull. The bregma is formed by the intersection of the sagittal and coronal sutures, and the vertex is the highest point on the skull and is many times near the midpoint of the sagittal suture. The sagittal suture is also known as the “interparietal suture” and the “sutura interparietalis.” (

    The sphenoid bone (os sphenoidale) is a bone situated at the base of the skull in front of the temporals and basilar part of the occipital. It somewhat resembles a bat with its wings extended, and is divided into a median portion or body, two great and two small wings extending outward from the sides of the body, and two pterygoid processes which project from it below. It articulates with the occiput forming the sphenobasilar synchondrosis.

    Spinal Dural Membranes
    See Dural Membrane

    A type of fibrous joint in which the opposed surfaces are closely united, as in the skull (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1620.)

    Sympathetic Nervous System
    A branch of the autonomic nervous system. It is always active at a basal level (called sympathetic tone) and becomes more active during times of stress. Its actions during the stress response comprise the fight-or-flight response. (

    1. A union between adjacent bones or parts of a single bone formed by osseous material, such as ossified connecting cartilage or fibrous tissue. 2. The osseous union of bones that is nomally distinct. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1648.)


    Temporal Bone (os temporales)
    Situated at the sides and base of the skull consisting of five parts: the squama, the petrous, mastoid, and tympanic parts, and the styloid process.

    Third Order Waves
    A third motion present in the body distinct from respiration and heartbeat. (The Heart of Listening, by Hugh Milne, 1998, vol. 1, pg. 171.)

    Transcranial Ultrasound Doppler Echography
    A non-invasive ultrasound wave imaging modality utilized for measuring the flow rate of fluids within the cranium.

    Traube-Hering and Meyer Oscillations
    Rhythmical variations in blood pressure, usually extending over several respiratory cycles, with a frequency varying from 6 to 10 cycles a minute, related to variations in vasomotor tone. The phenomenon was discovered by Traube in 1865 and confirmed by Hering in 1869. In 1876 Siegmund Mayer observed similar oscillations. According to some writers, Mayer’s waves is a separate entity, described as oscillations of low frequency, non-synchronous with ventilatory pattern. [Bibliography: *L. Traube: Ueber periodische Thätigkeits-Aeusserungen des vasomotorischen und Hemmungs-Nervencentrums. Centralblatt für die medicinischen Wissenschaften, Berlin, 1865, 3: 881-885. * S. Mayer: Studien zur Physiologie des Herzens und der Blutgefässe 6. Abhandlung: Über spontane Blutdruckschwankungen. Sitzungsberichte Akademie der Wissenschaften in Wien. Mathematisch-naturwissenschaftliche Classe, Anatomie, 1876, 74: 281-307 *Karl Fahrenkamp: Beitrag zur Kenntniss der Tagesschwankungen bei der Hypertonie. Medizinische Klinik, Berlin, 1921, 26: 790-792.](

    A wound or injury, whether physical or psychic. Birth t., an injury to the infant received in or due to the process of being born. In some psychiatric theories, the psychic shock produced in an infant by the experience of being born. Occlussal t., injury to any part of the masticatory system as a result of occlusal dysfunction. Psychic t., an emotional shock that produced an emotional or mental disorder. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1746.)


    Pertaining to blood vessels or indicative of a copious blood supply. (Dorland’s illustrated medical dictionary, Philadelphia: W.B. Saunders Co., ed.27, pg. 1808.)