Intro to the NS Flashcards
contralateral
sensory or motor deficits occurring on the oppo side of the causative lesion
ipsilateral
sensory or motor deficits occurring on the same side as the causative lesion
somatotopic
sensory or motor pathways convey their fibers in a highly organized laminated fashion as they ascend or descend to specific regions of the cortex or body
homunculus
cartoon representation of the exaggerated proportions of the cortical map
funiculus
general term for a large cord-like bundle of n fibers
fasciculus
general term referring to a bundle of n fibers which belong to a particular system in the CNS
tract
specifically defined as a fasciculus comprised of n fibers that have a common origin termination and function
lemniscus
crossed secondary n fibers in a conscious sensory pathway
lesion leads to contra lateral deficit
falx herniation
falx partially separates the cerebral hemispheres
unilateral space occupying lesions leads to herniation across the midline beneath the free edge of the falx
singular event may not present clinical deficits associated w/ herniation
epiderual hematoma
rupture of the middle menigeal a
blood b/w endocranium and dura mater
clinically: initial unconsciousness followed by rapid recovery
after a few hours displacement of the brain tissue
tentorial or uncal herniation
herniation through the tentorial notch
compression of the brainstem
subdural hematoma
rupture of the cerebral v to rupture as they cross the subdural space
signs and symptoms of epidural hematomas, may be delayed a few weeks
trauma to the midbrain
sharp edge of the incisura to lacerate or contuse the brainstem
damage to the midbrain reticular formation will cause damage to consciousness
dural venous sinuses
superior sagittal sinus - R transverse sinus
straight sinus - left transverse sinus
thrombosis of the posterior portion of the superior venous sinus or R transverse sinus
cortical ischemia and/or necrosis
thrombosis of the posterior portion of the straigh venous sinus or left transverse venous sinus
ischemia and or necrosis of structures in the deep cerebrum
usually fatal
pailledema
increased intracranial pressure applies pressure to sm v on the optic n decreasing venous drainage leading to edema of the retina and swelling of the optic disc
subarachnoid hemorrhage
all major BV run in subarachnoid space
rupture of one vessels leads to subarachnoid hemorrhage
indicated by erythrocytes in the CSF
layers moving down from skull
dura mater subdural space arachnoid membrane subarachnoid space pia mater
CSF production and flow
choroid plexus in each ventricle drains towards the 4th ventricle and into the subarachnoid space at or above the level of the foramen magnum
most CSF s absorbed in the subarachnoid space at the level of the superior sagittal venous sinus
lateral ventricle
core of each cerebrum
most frequently enlarges in hydrocephaly
interventricular foramen of monroe
connects lateral ventricle to the third ventricle
third ventricle
continuous w/ two lateral ventricles
cerebral aqueduct
third ventricle
boundary b/w tectum and midbrain tegmentum
fourth ventricle
continuous w/ cerebral aqueduct
external hydrocephalus
excessive accumulation of CSF in the subarachnoid space w/ concomitant enlargement of the space by compression of CNS
supratentorial external hydrocephalus
most commonly associated w/ senile atrophy of the cortex
ex AD
infratentorial external hydrocephalus
seen in combination w/communicating hydrocephalus
internal hydrocephalus (noncommunicating)
does not drain into the subarachnoid space
due to obstruction of the interventricular foramen, choroid plexus, cerebral aqueduct, and medial and lateral foramina
results in dilation of the ventricles proximal to the obstruction
communicating hydrocephalus
combination of infratentorial external and internal hydrocephalus
obstruction of subarachnoid space at tentorial notch
CSF can move into infratentorial subarachnoid space but not over the cerebrum to be resorbed at the arachnoid villi
result is hypertrophy of the ventricles and accumulation of CSF in the infratentorial subarachnoid space
shunt in cisterna magna to drain
watershed infarction
distal areas of cerebral arterial circulation are hypoperfused
ischemic penumbra
following focal ischemia the tissue surrounding the core ischemic territory is too ischemic to function
auto regulation dysfunction and edema
due to ischemic tissue acidosis and resultant luxury perfusion of adjacent normal tissue
electrical failure
tissue is viable but cessation of brain electrical activity including attenuation of EEG and absence of cerebral evoked potentials
ionic failure
irreversible tissue damage due to hypoperfusion
circle of willis
anterior cerebral a anterior communicating a middle cerebral a ant choroidal a posterior communicating a posterior cerebral a
parkinsons and ant choroidal a
ligation will lead to decreased tremors on the opposite side
recurrent a of heubner
supplies the internal capsule and the corpus striatum
anterior cerebral a (ACA) cortical area
paracentral lobule
paracentral lobule
occlusion of the ACA or superior sagittal sinus may result in sensory and or motor deficits in the CONTRALATERAL leg and foot
middle cerebral a (MCA) cortical area
primary motor cs, premotor cx, broca’s speech area, primary somesthtic cx, primary auditory cx, wernicke’s area
posterior cerebral a (PCA) cortical area
primary visual cx
Anterior spinal a (ASpA) penetrating branches
central portion of cord
Posterior spinal a (PSpA) penetrating branches
posterior 1/3 or cord
expressive or broca’s aphasia
motor language disorder characterized by cryptic telegraphic speech w/ a frustrating problem in initiation of speech motor patterns
automatic profane speech patterns may persist
wernicke’s aphasia
receptive language disorder
pts are quite fluent but lack content or meaning in their spoken and written comprehension of language
language pattern tends to circumlocute w/ numerous inappropriate word choices and neologisms
central cord syndrome
disruption of BF to the anterior spinal a
ischemia of the central region of the spinal cord
central necrosis and cavitation of the spinal cord and the development of a syrix
lateral medullary (wallenberg) syndrome
displacement of the PICA on angiograms of the post cranial fossa may indicate the presence of a space occupying mass such as a tumor
thrombosis of PICA
internal cerebral v
receives - thalamostriate and ant septal v
drains - great v of galen
basal v of rosenthal
receives - middle deep cerebral and anterior cerebral v
drains - great v of galen
great v of galen
receives - internal cerebral and basal v
drains into the straight sinus
L straight sinus
drains core, more dangerous to block
R straight sinus
drains cortical region
