Ennis Lecture Lets try this again Flashcards
Describe the Dura
The dura is a dual structure with an inner meningeal layer and an outer periosteal layer (endocranium) which is intimately applied to the inner surface of the cranial bones (serving as a periosteum) and which becomes continuous with the pericranium (periosteum of the skull surface) at the various foraminae (Latin=windows) of the skull.
How are venous sinuses formed?
At certain locations, the two layers separate to form venous sinuses. triangular in coronal section and usually associated with bone, these are made of dura. The layers then rejoin to form one of four partitions which insinuate themselves between subdivisions of the brain.
What is the Falx Cerebri
Falx cerebri (Latin: falx=sickle)–a strong membrane extending down into the longitudinal fissure between the two cerebral hemispheres;
Where is the Falx attached?
attached to the skull bones along the midline of the inner surface of the cranial vault from the crista galli (Latin: cock’s comb) to the internal occipital protuberance;
What is contained in the superior aspect of the falx?
What is contained in the inferior aspect?
superior attachment contains the superior sagittal sinus; free margin contains the inferior sagittal sinus
What is the Tentorum Cerebri?
Tentorium cerebelli (Latin: tentorium=roof)–a transverse shelf of dura separating cerebellum from the occipital poles of the cerebral hemispheres;
Where is the Tent Attached?
Attached laterally and posteriorly to the transverse sinuses; attached anteriorly to the superior border of the petrous (Greek: petros=rock) temporal bone and the posterior clinoid processes; becomes continuous with the falx cerebri along the midline where the two meet at right angles to form the straight sinus; free border extends anteriorly to the anterior clinoid processes
What is the triangular process attached to the inner surface of the occipital bone; projects into the posterior cerebellar notch between the two cerebellar hemispheres
Falx Cerebelli…. Not to be confused with Cerebri they are different.
What is the roof of dura covering the pituitary; this roof is incomplete to allow the stalk of the hypophysis to reach the hypothalamus
Diaphragma sellae (Latin: cover over the saddle)
Where does the Dura get its blood supply from?
dura receives most of its blood supply from the middle meningeal arteries which are branches of the maxillary artery off the external carotid.
Where does the middle meninginal artery run?
These middle meningeals ascend through the foramen spinosum on either side and course outside the periosteal layer of dura forming a groove in the skull; they supply the skull as well as the dura and are frequently injured in skull fractures
What is the sensory innervation to the dura?
sensory innervation to the dura is by branches of the FIFTH cranial nerve, the trigeminal. Each of its 3 divisions gives off a sensory branch to the dura.
What vessels are often injured in skull fractures?
Middle Meningeal arteries
What is the Delicate connective tissue membrane closely applied to the brain. It carries the rich network of blood vessels which supply the nervous tissue. It invests the entire surface of the brain, dipping into the fissures and sulci of the cerebral and cerebellar hemispheres.
Pia Mater (Pia + Arachnoid=Leptomeninges)
What is the avascular membrane lying between the dura and pia
Arachnoid Mater
Where is CSF synthesized?
choroid plexus
Where does CSF enter the subarachnoid space?
What are the wide intervals made at the base of the brain by the subarachnoid space?
4th ventricle
Subarachnoid Cysterna
What allows CSF to flow between the third and fourth ventricles
Cerebral aquaduct
How does blood brain from the arachnoid membrane to the superior sagital sinus?
Arachnoid villi clump together to form arachnoid granulations that penetrate the dura to absorb CSF into the superior sagital sinus.
If you have a hemhorrhage between the skull and the dura what space of the skull would this be in?
Epidural or Extra axial hemhorrhage
What lobes of the brain occupy the anterior cranial fossa?
Frontal lobes
What passes through foramen rotundum?
Maxillary Nerve (V2)
What passes through foramen oval?
Mandibular Nerve V3 and Accessory meningeal artery
What passes through foramen spinosum?
Middle meningeal vessels
