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88 Cards in this Set
- Front
- Back
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What makes up the anatomical CS system? |
- Membrane system (surrounds & envelopes the CNS) - Bones of the cranium & sacrum (attach to the membrane system) - Cerebrospinal fluid (fills the membrane system) - Fascia (radiates out from the membrane system) |
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What's the tripple layered membrane system called?
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The meninges |
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What layers make up the meninges? |
- Pia mater - Arachnoid mater - Dura mater Mater = mother |
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Explain their structure of Pia, Arachnoid? |
- Pia mater envelops CNS - Subarachnoid space = cerebrospinal fluid-filled space (inside arachnoid mater, outside pia mater). Contains arachnois villus (tiny cerebral blood vessels) that supply O2 to cortex. - Arachnoid mater (spiderweb structure of connective tissue which creates a network passing between arachnoid mater & pia mater via subarachnoid space) |
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Explain their structure of Dura Mater? |
- 'Tough mother' - Outermost layer - Protects CNS from surrounding environment - Impermeable to fluids - Attaches the membrane system to bones |
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What's the difference between the cranial dura and the spinal dura? |
The cranial dura encases the cranium and the spinal dura encases the vertebral column but they are not separate structures. |
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What are the two layers of subdivided dural membrane? |
- Outer layer / ENDOSTEAL layer - Inner layer / MENINGEAL layer |
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What differentiates them? |
They have separate blood supply, nerve supply and separate functions |
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What's the periosteum? |
The membranous layer which envelopes the outer surface of the cranial bone, forming a membranous sac containing the bones of the cranium. |
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Describe the structure of the outer layer / ENDOSTEAL layer? |
- Forms a lining to the internal surface of the bones & cranium - Continuous with the periosteum |
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Describe the structure of the inner layer / MENINGEAL layer? |
- Lining within a lining and folds in to form several infoldings which (along with pia & arachnoid mater) partially divide the intracranial space into sections. - Infoldings = Intracranial membranes |
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What do these infoldings / Intracranial membranes form? |
Venous sinuses which determine the pathways of drainage (draining deoxygenated venous blood from the brain, thereby enabling a supply of oxygenated arterial blood). All part of a continuous membranous sheath. |
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What are the 4 principal infoldings? |
1) Falx Cerebri 2) Falx Cerebelli 3) Tentorium Cerebelli 4) Diaphragma Sellae |
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Describe shape and location of Falx Cerebri? |
- Sickle-shaped - Running from front to back along the midline between 2 cerebral hemispheres. |
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Describe shape and location of Falx Cerebelli? |
- Smaller sickle-shaped membrane - Passing down the midline of the occiptal region between two cerebellar hemispheres |
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Describe shape and location of Tentorium Cerebelli? |
- Tent-shaped, double-layered membrane - Passing horizontally across the cranium, dividing the cerebrum above & cerebellum below. |
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Describe shape and location of Diaphragma Sellae? |
- Small, horizontal membrane - Forms a roof over Sella Turcica of Sphenoid - Envelopes the pituitary gland |
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Where do the Falx Cerebri, Falx Cerebelli & Tentorium Cerebelli meet? |
At the straight sinus. |
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What is the Reciprocal Tension Membrane System? |
Because the Meninges is a continuously interconnected membrane, tensions anywhere in the membrane system are transmitted reciprocally throughout the rest of the membrane system. |
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What is the implication of a Reciprocal Tension Membrane System? |
Tensions and imbalances within any part of the membrane system are liable to influence all other parts of the membrane system. |
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Where does the dural membrane form bony attachments in the cranium? |
1) Frontal bone 2) Parietals 3) Temporals 4) Occiput 5) Sphenoid 6) Ethmoid 7) C2 & C3 8) Sacrum 9) Coccyx |
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Where does the Falx cerebri attach? |
At the: - Ethmoid (anteriorly at the crista galli) - Frontal - Parietals - Occiput |
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Where does the Falx cerebelli attach? |
At the: - Occiput |
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Where does the Tentorium cerebelli attach? |
At the: - Sphenoid (at the clinoid processes) * - Temporals - Parietals - Occiput * Upper layer attaches to anterior clinoid processes / Lower layer attaches to posterior clinoid processes / |
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Where does the Diaphragma Sellae attach? |
At the: - Sphenoid |
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Where do the separate nerve supplies to the Tentorium originate |
Upper Leaf: From the ophthalmic branch of the trigeminal nerve Lower Leaf: From the upper cervical spinal nerves |
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What does the nature of this Tentorium structure (separate sources & nerve supplies) imply? |
That the it can be influenced and affected separately by different factors. |
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Why is the attachment of these infoldings described as "indirect"? |
Because the Inner Layer of the Dura is coming into contact with the bones through the Outer Layer of the Dura. The outer layer is uniformly attached to the bones throughout their inner surface. |
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What is significant about the ridges of bone standing out from the inner surface of the cranium? |
It's a clear indication of the forces transmitted through these membranes. |
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Why is knowing about the membranous attachments significant? |
They play an integral part in the rhythmic motions of the cranium & establish fulcrums around how individual bones express their expansive/contractive movements. |
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What layers is the spinal dura subdivided into? |
- Outer layer - ENDOSTEAL layer lining the bony vertebral canal - Inner layer - MENINGEAL layer enveloping the spinal cord |
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Where does the Meninges/Dural Tube attach to the vertebral canal? |
1) Foramen magnum 2) C2 & C3 (anterior wall of vertebral canal) 3) Sacrum (anterior wall of S2) 4) Coccyx via the Filum Terminale (posterior surface of 1st coccygeal segment) * Other than these attachment locations, the dural tube floats freely. |
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What's the Filum Terminale? |
A thin filament of membrane (Pia/Arachnoid/Dura) which passes down from the lower end of the spinal cord & attaches to the coccyx |
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How is the Dura attached to the Pia Mater? |
It loosely attaches by "denticulate ligaments"§ passing between the two membranes (particularly in the lower part of the spine) |
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How does the Dura interact with nerves running back and forth from the CNS to the PNS? |
The Dural Membrane is penetrated by the nerves that exit/enter from the CNS & travel to the PNS (& visa versa). The Dura envelops each nerve at the point of penetration before blending into the Epineurium. |
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What is the Epineurium & how does it interact with the Dura? |
The fascial sheath which envelopes the nerve on its pathway between the CNS and PNS. The Dura envelops each nerve at the point of penetration before blending into the Epineurium. This provides a continuity between the Dura and the fascia. |
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What are some common disturbances in the membrane system? |
Meningitis / meningisms / sclerosis from inflammation / meningeal cysts / arachnoiditis / emotional tension / sympathetic stimulation / intrinsic pulls & imbalances within the reciprocal tension membrane system. |
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What widespread effects can occur from an imbalances within the reciprocal tension membrane system? |
- impinging on nerves/nerve roots - constricting blood vessels - restricting movement of bones - transmitting imbalances throughout the body - disturbed nerve & visceral function - severe pain - chronic ill health - trigger old injuries/weak areas |
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What are the consequences of membranous restrictions in the cranium? |
- impinge on cranial nerves that pass through formina of the cranium - squint - Bell's palsy - Trigeminal neuralgia - impinged vagus nerve = disturbed visceral function, colic, digestive/respiratory/cardiac dysfunction. - Influence venous sinus drainage & arterial supply to the brain - membranous contractions can lead to headaches, migraines, congestion, contraction, vagueness & confusion - Common persistent symptoms after meningitis |
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BONES |
BONES |
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What bones attach directly to the membrane system? |
1) All the bones of the cranium 2) C2 & C3 3) Sacrum 4) Coccyx |
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What are the bones of the cranium? |
- Frontal - Parietals - Temporals - Occiput - Sphenoid - Ethmoid |
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Using a lateral skull, identify the location of these bones/sutures. |
Parietal bone Occiput External occipital protuberance Temporal bone Mastoid process Styloid process Frontal bone Sphenoid (GW) Zygoma Maxilla Mandible Coronal suture Squamosal suture Lamdoid suture |
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Using a anterior skull, identify the location of these bones & foramen. |
Frontal bone Nasal bone Zygoma Maxilla Mandible Sphenoid (GW & LW) Ethmoid (orbital plate & perpendicular plate) Lacrimal bone Vomer Supraorbital foramen Infraorbital foramen Mental foramen |
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Using a inferior view of the skull, identify the location of these bones & foramen. |
Foramen magnum Maxilla Palatine bone Zygoma Sphenoid (medial pterygoid / lateral pterygoid / greater wing) Spheno-basilar synchondrosis Temporal bone Zygomatic process Styloid process Mastoid process Squama Occipital mastoid suture Parietal bone Lamoid suture Occipital bone Condylar portion Condyle Basilar Portion (Basiocciput) Superios nuchal line External occipital protuberance (inion) Squamous portion |
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Using a superior & interior view of the skull, identify the location of these bones & foramen. |
Ethmoid notch Crista galli Cribriform plate Frontal sinus Orbital portion Spheno-frontal suture Spheno-temporal suture Spheno-basilar synchondrosis Squamosal suture Foramen magnum Jugular foramen Occipital-mastoid suture Lamoid suture Groove for sigmoid sinus Groove for transverse sinus Confluence of sinuses Internal occipital protuberance Ridges for attachment of: Falx cerebri / Falx cerebelli / Tentorium Squamous portion Condylar portion Basilar portion Parietal bone Petrous portion Petrous ridge Sphenoid: Pituitary fossa / lesser wing / anterior clinoid process / Posterior clinoid process / greater wing |
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Using a superior & exterior view of the skull, identify the location of these bones and sutures. |
Frontal bone Parietal bone Occiput Coronal suture Bregma Sagittal suture Lamda Lamdoid suture |
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What is Cerebrospinal Fluid? |
The pure fluid which surrounds the CNS. |
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What does it do? |
Provides nutrition & drainage for the brain & spinal cord. |
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Where is it contained? |
- Ventricular system - Subarachnoid space |
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What is the ventricular system? |
The system of cavities & canals (deep within brain & spinal cord) where cerebrospinal fluid is formed & contained |
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What's the Ependyma? |
Thin pia-like membrane which lines the ventricles |
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What are the four ventricles within the system? |
- 2 x Lateral ventricle - 3rd ventricle - 4th ventricle |
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Where are they located? |
Lateral ventricle: - within 2 cerebral hemispheres (communicating via the interventricular foramen with the 3rd ventricle) 3rd ventricle: - located centrally between 2 thalami (communicates inferiorly via the cerebral aqueduct/Aqueduct of Sylvius) 4th ventricle: - between the cerebellum & the pons & medulla - continuously inferior - central canal passing down centre of spinal cord |
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What is the Choriod Plexi? |
The vascular structures in the Ventricle System where cerebrospinal fluid is produced (extracted from arterial blood) |
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Where is the Choriod Plexi located? |
In the roof of each of the 4 ventricles |
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What's the Foramina (in the 4th ventricle)? |
- Foramen of Magendie (posterior wall) - 2 x Foramina of Luschka (lateral wall) |
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What does the Foramina do? |
Allow cerebrospinal fluid to pass to the subarachnoid. |
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What does cerebrospinal fluid in the arachnoid space allow for? |
For cerebrospinal fluid to be circulated around the brain and spinal cord. |
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How is cerebrospinal fluid returned to the blood? |
Via the Arachnoid Villi |
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What are the Arachnoid Villi? |
Protrusions of arachnoid membrane through the dura of the venous sinuses, through which the cerebrospinal fluid can return to the venous blood. It can also drain into the olfactory nerve pathways & into the lymphatic system, as well as, other cranial nerves. |
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Where does the venous blood drain from? |
From the Venous Sinuses via the 2 internal jugular veins, through the jugular foramina, & back to the heart. |
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What are Cisternae? |
A site of accumulation of cerebrospinal fluid within the subarachnoid space. - Cisterna Magna - Lumbar Cisterna |
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Where is the Cisterna Magna? |
Behind the medulla, bellow the cerebellum |
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Where is the Lumbar Cisterna? |
In the lower spine (where it's taken for lumbar puncture) |
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Label diagrams on Pg 40/41/43 |
Okay I will |
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What are the Venous Sinuses? |
The system of sinuses/spaces in the Dura through which venous blood collects in order to return to the heart for re-oxygenation |
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How are Venous Sinuses formed? |
Between two layers of dural membrane |
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What are Venous Sinuses layered with? |
Endothelium |
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What makes Venous Sinuses differ from veins? |
- Contain no valves - Some have blind ends - Walls contain no muscular tissue |
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What do the Venous Sinuses comprise of? |
1) Superior Sagittal Sinus 2) Inferior Sagittal Sinus 3) Straight Sinus 4) Occipital Sinus 5) Two transverse Sinuses 6) Two Sigmoid Sinuses 7) Two Cavernous Sinuses 8) Circular Sinus 9) Two Superior Petrosal Sinuses |
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Describe the location of the Superior Sagittal Sinus & how it drains? |
Location: along superior border of falx cerebri Drains: posteriorly towards confluence of sinuses |
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Describe the location of the Inferior Sagittal Sinus & how it drains? |
Location: along the inferior border of falx cerebri Drains: posteriorly into the straight sinus |
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Describe the location of the Straight Sinus & how it drains? |
Location: along the border between falx cerebri, falx cerebelli & tentorium Drains: posteriorly towards confluence of sinuses |
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Describe the location of the Occipital Sinus & how it drains? |
Location: along the occipital border of falx cerebelli Drains: superiorly towards confluence of sinuses |
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Describe the location of the Two Transverse Sinuses & how it drains? |
Location: along the attached occipital border of the tentorium Drains: laterally away from the confluence of sinus into the sigmoid sinuses |
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Describe the location of the Two Sigmoid Sinuses & how it drains? |
Location: S-shaped sinuses twist inferiorly along grooves in the petrous portions of the temporal bones towards the jugular foramina. Drains: inferiorly from the transverse sinuses into the internal jugular veins. |
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Describe the location of the Two Cavernous Sinuses & how it drains? |
Location: each side of sphenoid Drains: posteriorly (via the inferior/superior petrosal sinus) into sigmoid sinus. |
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Describe the location of the Circular Sinuses? |
Location: passing around pituitary, connects cavernous sinuses. |
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Describe the location of the Two Superior Petrosal Sinuses & how it drains? |
Location: passing from cavernous sinus to superior end of sigmoid sinus Drains: posteriorly into sigmoid sinuses |
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Describe the location of the Two Inferior Petrosal Sinuses & how it drains? |
Location: passing from cavernous sinus to inferior end of sigmoid sinus Drains: posteriorly into sigmoid sinuses |
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How much fluid is contained in the - ventricles & subarachnoid space - choroid plexi |
- ventricles & subarachnoid space = 150ml - choroid plexi = 600ml |
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What is Fascia? |
Connective tissue which forms a continuous sheath throughout the body - surrounding bones, muscles, nerves, blood vessels, organs. |
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Where does the fascial sheath connect to the membrane system? |
At the points where each peripheral nerve emanates from the CNS. |
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What's another name for the "fascial sheath" |
Epineurium |
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How does the Epineurium interact with the Dura? |
The membrane/Dura envelops each nerve at the point of penetration before blending into the Epineurium. This provides a continuity between the membrane/Dura and the fascia. |
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What's a consequence of the unity structure of fascia? |
Pulls, twists, restrictions & resistances may be transmitted through the body with repercussions elsewhere. Creating: tensions, perpetuating neurological symptoms, muscular weakness, restricting blood supply. |
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Does the fascia have a nerve supply? |
Yes, a very rich innervation of sympathetic nerves |
