Module 1 Meninges and CSF Flashcards
Meinges are the three layers of membranes covering surrounding the
brain and the spinal cord.
It has 2 components:
1. ____ which is a mesodermal derivative and composed of _____ mater
2. _____which is a neural crest derivative
and composed of ____ mater and ___ mater.
- Pachymeninx, dura
- Leptomeninx, arachnoid
pia mater
DURA MATER
Other Name: 1.\_\_\_\_\_\_\_ Definition: Cushion between the brain and rigid skull Origin: 2. \_\_\_\_\_\_ Characteristics: -Outermost layer -Tough, collagenous, dense CT membrane Composed of 2 layers 3. \_\_\_\_\_\_ 4. \_\_\_\_\_\_\_
- Pachymeninx; “shower curtains”
- Mesodermal
- Periosteal Layer
- Meningeal Layer
The layers of dura are closely united except along ______ and when the inner meningeal layer forms septa
venous sinuses
At the sutures, Periosteal/ Endosteal Layer (Outer) becomes continuous with the ________.
Periosteal/ Endosteal Layer (Outer) does NOT become continuous with the dura mater of the spinal cord
sutural ligament
-Dura mater proper
Meningeal Layer (Inner)
Dense, strong fibrous membrane
Continuous with the dura mater of the spinal cord
Meningeal Layer (Inner)
Function of Meningeal Layer (Inner)
Provides tubular sheaths for the cranial nerves as they pass through the skull’s foramina
four septa of Meningeal Layer (Inner)
- Falx cerebri
- Tentorium cerebelli
- Falx cerebelli
- Diaphragm sellae
_____ is the LARGEST septum of meningeal layer that extends from Crista galli to Occipital Protuberance. It extends down and projects from the longitudinal fissure between the cerebral hemispheres. It is continuous posteriorly with the ______.
Falx Cerebri
Tentorium Cerebelli
A dural reflection from the petrous part of the temporal bone which covers the dorsal surface of the cerebellum and where the occipital lobes lie
-Tentorium Cerebelli
Falx cerebri attaches
ANTERIOR: _______
POSTERIOR: _______
- internal frontal crest and crista galli
2. the internal occipital protuberance (blends with the tentorium cerebelli in the midline)
Drains blood from the lateral aspects of anterior cerebral hemispheres confluence of sinuses
Superior sagittal sinus
Allows blood to drain outwards posteriorly from the center of the head
Inferior sagittal sinus
Tentorium Cerebelli contains a wide gap known as the ______
“tentorial notch/ incisura tentorii”
Tentorium Cerebelli attachments:
Upper Attachment: _______
Lower Attachment: _______
Superior: _______
Inferior: _______
Falx cerebri (Fuses with this midline)
Falx cerebelli is attached to its lower surface
Cerebrum
Cerebellum
Functions to separates occipital lobe (cerebrum) from cerebellum and to permits the passage of the midbrain anteriorly (free anterior border)
Tentorium Cerebelli
Small midsagittal septum below the tentorium cerebelli and partially separates the two cerebral hemispheres
Falx Cerebelli
Posterior margin of Falx Cerebelli contains the ______
occipital sinus
- Roofs over the sella turcica
- Perforated by the infundibulum
Diaphragma Sellae
Blood Supply and Innervation of the brain:
- ____ – give rise to middle meningeal branches
- ____– MAJOR blood supply
- _____ – give rise to anterior meningeal branches
- ______ – give rise to posterior meningeal branches
- _______ – supplies the Supratentorial dura compartment
- ________ – supplies the Infratentorial dura compartment
- Maxillary Artery
- Middle Meningeal Artery
- Opthalmic Artery
- Occipital and Vertebral Arteries
- Trigeminal Nerve (CN V
- Upper Cervical Spinal and Vagus Nerves (CN X
finger-like extensions in the arachnoid mater
Arachnoid villi
space between arachnoid and pia filled with blood vessels and CSF
Sub-arachnoid space
Composition of arachnoid mater
Leptomeningeal Cells
-Intermediate layer of the meninges that lines the dura. Film-like; pass over the sulci BUT doesn’t follow its contours. Delicate, non-vascular membrane
ARACHNOID MATER
-found at the base of the brain and around the brainstem where the pia and arachnoid are widely separated
Subarachnoid Cisternae
- Lies between cerebellum and medulla oblongata
- Receives CSF from 4th ventricle from median aperture
cerebellomedullary Cistern/ Cistern Magna
cerebellomedullary Cistern/ Cistern Magna contains what vessels and nerves?
Vertebral artery,
CN 9-12,
Origin of Posterior Inferior Cerebellar Artery (PICA)
- Surrounds ventral aspect of pons
- Receives CSF via lateral apertures
Pontine Cistern
Pontine Cistern contains what vessels and nerves?
Basilar artery,
CN 6,
Origin of Superior Cerebellar Artery (SCA)
-At the base of the brain; between the twocerebral pedunclesofmidbrainanddorsum sellae
Interpeduncular Cistern
Interpeduncular Cistern contains what vessels and nerves?
CN 3 (and so many other things we can’t even understand yet so CN 3 lang anay ah)
-Continuous with the Pontine and Interpeduncular cisterns
Chiasmatic Cistern
-Surrounds the superior, posterior, and lateral surfaces of the midbrain
It is situated dorsal to the midbrain
Superior Cistern/ Cisterna Ambiens
Superior Cistern/ Cisterna Ambiens contains what vessels and nerves?
Great cerebral vein,
Vein of Galen,
PCA and SCA, CN IV
-Extends from conus medullaris to S2; contains the filum terminale and nerve roots of cauda equine. It extends from the conus medullaris (L1-L2) to about the level of the second sacral vertebra.
Lumbar Cistern
Lumbar Cistern contains what vessels and nerves?
the filum terminale and the nerve roots of the cauda equina.
Innermost layer, closest to the brain
Adheres closely to the Ependymal cells (Si plankton!) of the ventricles
PIA MATER
____ has the ff. characteristics:
Thin & translucent, delicate CT membrane
Glove-Like Adheres closely to the brain surface covering the gyri and descends into the sulci (Unlike Arachnoid)
PIA MATER
Composition of PIA MATER
Leptomeningeal Cells
Collagen & Elastic fibers
Fibroblasts
function of PIA MATER
Membrane of nutrition
- Strong vascular duplications into the brain formed by the pia mater
- Spreads over the 3rd and 4th ventricular cavities
Tela Choroidea
-Formed by the 2 layers of pia mater in the transverse cerebral fissure, below the splenium of the corpus callosum and above the pineal body; where the internal cerebral veins, branches of the PCA, and arteries of the choroid plexuses of the 3rd and lateral ventricles lie
Velum Interpositum
- Inner membranous layer of pia metter adherent to underlying nervous tissue
- -Composition: fine reticular & elastic fibers
- Avascular & gets nutrition by diffusion from CSF & underlying nervous tissue
Intima Pia
Space in the pia mater formed between blood vessels & its adventitial sheath which permits CSF flow from SAS into brain parenchyma
perivascular space or Virchow-Robin space
- More superficial
- Composition: collagenous fiber bundles continuous with arachnoid trabeculae
- Absent over the convex surface of cerebral cortex
- Where blood vessels of the spinal cord lie
Epipal Layer
Lateral flattened bands of epipal tissue that attach spinal cord to the dura matter
-Denticulate ligaments
The cerebrospinal fluid (CSF) occupies about ____of the total 1600-1700ml cerebral cavity enclosing the brain and spinal cord
150ml
True or False
CSF has higher Na+, Cl-, & Mg 2+; lower K+, Ca2+, & glucose (Compared to plasma ultrafiltrate)
true
CSF Pressure:
- Pressure maintained at a CONSTANT level
- Recumbent: ____
- Sitting position: _____
10-15cmH2O
20-30cmH2O
