Title: Anatomi & Histologi 2 - Adrian / (3) CNS III / (3.2) Meninges

Text: Beskriv Dura mater
Dura mater består av två blad, ett osteal (mot skallben) och ett meningealt (hjärnhinnebladet). Utrymmet mellan de två bladen kallas då för Sinus durae matris och fylls upp av venöst blod.
Dessa två blads relation till varandra är att de sitter ihop till största del men kan delas upp vid vissa områden, t.ex när hemispherium cerebri möts eller där cerebrum och cerebellum möts.

Framsida: Var finner du epiduralrummet respektive subduralrummet? Är det fysiologiska rum?
Baksida: Epiduralrummet är mellan dura mater och kraniet medans subduralrummet är mellan dura mater och arachnoidea. Utrymmet uppstår endast vid skador, till exempel om det uppstår blödning mellan de olika lagrena.

Front: Vad består meninges av?
Back: Meninges är de tre membranlagrena som skyddar hjärnan.
1. Dura mater
2. Arachnoidea
3. Pia mater

Text: Beskriv Arachnoidea
Är ett tunt lager bindväv som är kontinuerligt med dura mater. Består av lucker bindvävsfibrer och utsträckta fibroblaster.
Bindväven bildar trabekler som sträcker ut sig mot underliggande lager → här finns cerebrolspinalvätskan och stora blodkärl i s.k. subarachnoidalrummet

Text: Pia mater
Q: Är ett [...] som ligger [...] → är kontinuerligt med [...].
A: tunt lager bindväv; direkt på hjärnans (och ryggmärgens) yta; hjärnans vindlingar

Front: Describe the meninges shortly
Back: 1. Dura mater (dura): tough, thick external fibrous layer.
2. Arachnoid mater (arachnoid): thin intermediate layer.
3. Pia mater (pia): delicate internal vasculated layer.
- arachnoid and pia are continuous membranes

Text: Extradural blood accumulations
Q: Extradural ([...]) [...]is caused by blood from torn branches of a middle meningeal artery accumulate between [...].
A: epidural; hemorrhage; the periosteal layer of the dura and the cranium
Extra: Usually this follows a hard blow to the head, and forms an extradural (epidural) hematoma.Typically, a brief concussion (loss of consciousness) occurs, followed by a lucid interval of some hours. Later, drowsiness and coma (profound unconsciousness) occur. Compression of the brain occurs as the blood mass increases, necessitating evacuation of the blood and occlusion of the bleeding vessel(s).

Text: Dural border hematoma
Q: A dural border hematoma is commonly called a [...]. However, this term is a misnomer because there is no actual “subdural space” at the [...]. Hematomas at this junction are usually caused by extravasated blood that splits open the dural border cell layer.
A: subdural hematoma; dura–arachnoid junction—only a potential one
Extra: Dural border hemorrhage usually follows a hard blow to the head that jerks the brain inside the cranium and injures it (e.g., hitting the dashboard or windshield in a motor vehicle accident). Sometimes the precipitating trauma may be trivial or forgotten. Dural border hemorrhage is typically venous in origin and commonly results from tearing a superior cerebral vein as it enters the superior sagittal sinus.

Text: Subarachnoid hemorrhage
Q: Subarachnoid hemorrhage is an extravasation ([...]) of blood, usually arterial, into the [...] space.
A: the leakage of blood from a blod vessel into the tissue around it; subarachnoid
Extra: Most of these hemorrhages result from rupture of a saccular aneurysm (sac-like dilation on the side of an artery), such as an aneurysm of the internal carotid artery

Text: Dura mater:
Q: The outer (periosteal) lamina of the dura is continuous with the [...]
● The inner (meningeal) lamina is a supporting layer that more closely reflects [...]
A: periosteum on the external surface of the cranium; the contours of the brain.
Extra: ● This inner layer separates from the outer layer in certain locations to form dural folds or reflections that penetrate the large fissures between parts of the brain, partially subdividing the cranial cavity into smaller compartments that prevent inertial brain movement.
● In separating from the periosteal lamina, intralaminar spaces are created that accommodate the dural venous sinuses, which receive the venous drainage of the brain and mainly drain, in turn, to the internal jugular vein.