Stephens - L7/8 Flashcards
Collection of cell bodies and dendrites
Is it myelinated?
Gray matter, NON-myelinated
Collection of neuronal axons
Are they myelinated?
What are the types?
White matter, YES
Fasciculus: n fibers belonging to particular CNS systm
Tract: fasciculus comprised fom same origin, same termination, same function
Lemniscus: secondary n fibers, conscious sensory pathway, limited but speciic, lesion results in contralateral deficits
Nucleus
Aggregation of neuronal cell bodies in CNS
Ganglion
Aggregation of neuronal cell bodies in the PNS
Cortex
Sheet-like later of gray matter covering the cerebral hemispheres
Why is trauma to the midbrain dangerous? What anatomical part lacerates the brainstem (Reticular formation)?
Midbrain is location or arousal centers and consciousness
Incisura’s sharp educe
Tonsillar herniation
Tonsil is part of the cerebellum, herniation goes inferior through the foramen magnum compressing the brainstem
Where does the superior sagital sinus empty? Thrombosis here damages what part of the brain?
Right transverse sinus
Cortex
The straight sinus drains into where? Thrombosis here causes damage to what?
Left transverse sinus
Structures deep to cerebrum
What is a subarachnoid hemorrhage?
Rupture of bv’s in the subarachnoid space, diagnostic finding is blood/RBCs in the CSF, often seen with hematomas
What vessel is prone to strong ejection pressures when ruptures?
Internal carotid artery
What path does the CSF take as it circulates?
Ventricular system –> infratentorial subarachnoid space –> supratentorial arachnoid space –> arachnoi villi inside venous lacunae –> superior sagital sinus
What are classic symptoms of hydrocephalus?
“Sundown eyes” and papilledema
Define external hydrocephalus.
Excessive amounts of CSF in the subarachnoid space which consquently enlarges the spaces due to increased pressures, can be supra/inratentorial or BOTH
Supratentorial external hydrocephalus is commonly associated with what?
Senile atrophy of cortex (AD)
Infratentorial external hydrocephalus is associated with what dx?
Seen in combination with communicating hydrcephalus
Define internal hydrocephalus.
CSF that is blocked off in the ventricles, CSF doesn’t enter suarachnoid space
Seen in combination with inratentorial external hydrocephalus in communicating hydrocephalus
Define communicating hydrocephalus.
Involves two hydrocephalus issues communicating with one another, infratentorial and internal hydrocephalus, CSF cannot cross the tentorial notch (infratentorial subarachnoid space –> supratentorial arachnoid space) causing a backup in the infratentorial space and ventricles, thus CSF cannot circulate over the cerebrum, caused by fibrotic tissue or an uncal herniation
What is the volume of blood that perfuses 100g of tissue per minute in the brain?
~53mL, hypoxic sx start around 25-30, ischemic penumbra at 10-20mL
What medications help treat ischemic penumbra?
ones that block NMDA R’s, Ca channel blockers
What is the major blood supplier to inferior 2/3rds of the spinal cord? Where does it arise from? What happens when it’s severed?
Great Anterior a o Adamkiewicz
Left inferior intercostals or superior lumbar a
Ischemic Necrosis of the spinal cord
What a may be compressed during an uncal herniation that leads to vision problems?
posterior cerebral a (PCA), supplies visual cortex which becomes ischemic during uncal herniation
Occlusion of what v is almost always fatal? What veins does it recieve/drain?
Great v of Galen, recieves the internal cerebral and basal veins
Sensory or motor pathway that convey their fibers in a highly organized fashion (parts of cerebral cortex, maor pyramidal and sensory systems)
Somatotopic
