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Meninges Objectives
Question | Answer |
---|---|
identify the functions of the meninges | 3 layers of connective tissue surrounding the CNS for protection (suspends nervous tissue, water jacket of CSF, limits movement of brain), CSF made and moves around, supports and vonveys, vasculature, |
pia mater | deepest layer, attached to underlying nervous tissue, denticulate ligament |
arachnoid | connected to pia mater by arachnoid trabeculations (muscle), separated by subarachnoid space, attached to dura mater with only potential space between |
subarachnoid space | CSF and expanded regions called cistern or cisterns |
dura mater | most superficial, thick, attached to arachnoid, subdural space is POTENTIAL only, the epidural space is fat and vein filled and superficial to dura |
nerves come from where | intervertebral foramen |
epidural space | superficial to dura, real |
subdural space | between arachnoid and dura mater, potential |
subarachnoid space | between pia and arachnoid, real |
cranial vs spinal meninges | epidural space is potential only, dura attached to inside of dural reflections (dividing sheets in braincase), dura split into two layers at dural sinuses - meningeal (inner) and periosteal (outer) |
major dural reflections | places where two face-to-face meningeal layers descend into the cranial cavity to form the septa that compartmentalize the brain = falx cerebri, tentorium cerebelli, diaphragma sellae, tentorial incisure (notch), and falx cerebelli |
Falx cerebri associated | superior sagittal sinus, inferior sagittal sinus, and straight sinus |
Cranial dura - artery and nerve | the middle meningeal a and the trigeminal nerve |
tentorium cerebelli associated | transverse sinus |
diaphragma sellae associated | cavernous sinuses |
describe falx cerebri | arch above cerebrum |
describe tentorium cerebelli | tent like structure |
describe diaphragma sellae | blood filled spaces with cranial nerves |
describe tectorial incisure (notch) | wraps around midbrain |
describe superior sagittal sinus | found above the cerebrum |
describe inferior sagittal sinus | found below and lateral to the superior sagittal sinus |
describe straight sinus | appears to flow in a straight line and is connected to the inferior sagittal sinus |
describe confluens of sinuses | found on the posterior part of the posterior part of the skull and connected to the straight sinus |
describe transerve sinuses | looks transverse, follows base of cerebrum horizontally |
brain herniations? Why does this happen? | caused when there is an increase in pressure, compression/displacement of nervous tissue, caused by tumors, hematoma, trauma |
subfalcine (herniation) | brain tissue is displaced under the falx cerebri |
transetentorial (central and uncal) (herniation) | herniation of the medial temporal lobe from the middle into the posterior fossa, across the tentorial opening. The uncus of the temporal lobe is forced into the gap between the midbrain and the edge of the tentorium. |
tonsillar (herniation) | characterized by the inferior descent of the cerebellar tonsils below the foramen magnum |
dural sinuses | venous channels found between the endosteal and meningeal layers of dura mater in the brain |
cisterns | spaces formed by openings in the subarachnoid space, an anatomic space in the meninges of the brain.[1] The space separates two of the meninges, the arachnoid mater and the pia mater. These cisterns are filled with cerebrospinal fluid |
epineurium | connective tissue sheath around peripheral nerves |
periosteum | connective tissue covering of bones |
Compare & contrast meninges of the cranial vault with vertebral canal. Should include comprehensive description of the three layers & spaces associated with them, pointing out where they are disposed similarly in those two regions & how they're different. | epidural space is potential only, dura attached to inside of dural reflections (dividing sheets in braincase), dura split into two layers at dural sinuses - meningeal (inner) and periosteal (outer) |