Lecture 7+8 Flashcards
what are the four layers of the cranial meninges
- Dura mater
Made up of an outer periosteal dura (contains arteries) and inner dura - Arachnoid mater
- Subarachnoid space (sinuses)
- Pia mater
Epidural hemorrhage
rupture of the meningeal arteries (MMA)
usually a fractured cranial bone cuts the artery (trauma)
blood will accumulate in the periosteal dura
will look biconvex or lentiform
pressure from blood accumulation will compress the brain
subdural hemorrhage
usually due to trauma induced rupture of the delicate veins
blood will accumulate between dura and arachnoid
will be a crescent shaped hematoma due to the low pressure of the venous system
Subarachnoid hemorrhage
usually due to the rupture of the cerebral A.
will have pain and/or headache
accumulates in subarachnoid space
Intracerebral hemorrhage
rupture of intraparenchymal branches of subarachnoid
arteries, such as the lenticulostriate arteries
will see blood in the ventricles
what arteries form circle of Willis
vertebral and internal carotid
they form an anastomoses at the basal diencephalon
what artery dominates the lateral side of the brain
the middle cerebral A.
what artery dominates the anteromedial surface of the brain?
anterior cerebral A.
what artery dominates the posteromedial surface of the brain
Posterior cerebral A.
what genes segment the telencephalon
Emx and Otx
what genes segment the diencephalon
Pax6
what genes segments the mesencephalon
Otx
what genes segments the metencephalon
Hox
Schizencephaly
congenital malformation of the cortex with deep creviced cortex (very deep sulci)
mutation in Emx
Hox genes and retinoic acid
Hox gene expression is determined partly by a longitudinal gradient of retinoic acid
Retinoic acid is produced by Hensen’s node.
intake of a lot of retinoic acid can mess with this gradient
