CST Anatomy Flashcards
What makes up the anatomical CS system.
- Membrane system (surrounds and envelopes the CNS)
- Bones of the cranium and sacrum (attach to the membrane system)
- Cerebrospinal fluid (fills the membrane system)
- Fascia (radiates out from the membrane system)
What’s the triple layered membrane system called?
The meninges
What layers make up the meninges?
- Pia mater
- Arachnoid mater
- Dura mater
Mater = mother
Explain the structure of Pia and Arachnoid matter?
- Pia mater envelopes CNS
- Subarachnoid space = cerebrospinal fluid filled space (inside Arachnoid matter, 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 and Pia mater via sub arachnoid space)
Explain the structure of Dura Mater
- Tough mother
- Outermost layer
- Protects CNS from surrounding environment
- Impermeable to fluids
- Attaches the membrane system to bones
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.
What are the two layers of subdivided dura membrane?
- Outer layer / ENDOSTEAL layer
- Inner layer / MENINGEAL layer
What differentiates the two layers of subdivided dura membrane?
They have separate blood supply, nerve supply and separate functions.
What is the periosteum?
The membranous layer which envelopes the outer surface of the cranial bone.
What is a fulcrum?
A fulcrum is a pivotal point around which a system operates
Where are the vertebral column fulcrums
C1 T4 T9 T12 L5
What is the fulcrum around which the bony structures of the cranio-sacral system operate?
The SBS, Spheno-basilar sychondrosis
What is the fulcrum for the membrane system?
Sinus straight - where the falx cerebri, falx cerebelli and tentorium cerebelli meet.
What is the falcrum for the central nervous system?
Laminate Terminalis, which forms the anterior wall of the third ventricle
Describe the shape and location of the Falx Cerebri
Sickle Shaped
Runs along the sagittal sinus, the midline between the two cerebral hemispheres
Attaches anteriorly to the crista galli
Posteriorly, it is connected with the upper surface of the cerebellar tentorium
Describe the shape and location of the Falx Cerebelli
Sickle shaped passing along the midline of the occiput
Its base is attached, above, to the under and back part of the tentorium cerebelli.
It is posterior to the lower division of the inner surface of the occipital bone
Describe the shape and location of the Tentorium Cerebelli
Tent shaped, double layered membrane
Passing horizontally across the cranium, dividing the cerebrum above and cerebellum below.
Describe the shape and location of Diaphragma Sellae
Small horizontal membrane
Forms a roof over Sella Turcica of Sphenoid and envelopes the pituitary gland.
Where do the Falx Cerebelli and Tentorium Cerebelli meet?
At the straight sinus
What is the Reciprocal Tension Membrane System
Because the Meninges are a continuously interconnected membrane, tensions anywhere in the membrane system are transmitted reciprocally throughout the rest of the membrane system.
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.
Where does the dural membrane form bony attachments in the cranium
Frontal Bone Parietals Temporals Occiput Sphenoid Ethmoid C2 & C3
Where does the Falx Cerebri attach
Ethmoid (anteriorly at the crista galli)
Frontal
Parietals
Occiput
Where does the Falx Cerebelli attach
Occiput
