Supratentorial Brain Flashcards
Complex convolutions of brain cortex
Gyri
CSF-filled grooves or clefts that separate gyri
Sulci
Parts of frontal, temporal and parietal loves that overhang/enclose insula
Operculae
Two cerebral hemispheres are linked by
Commissural fibers
Cerebral hemispheres are separated by
Deep median cleft, the great longitudinal interhemispheric fissure
Central sulcus of rolando separates
Frontal and parietal lobes
Sylvian fissure separates
Frontal and parietal lobe from temporal lobe below
What is anterior to angular gyrus
Temporal lobe
Anterior to parietooccipital sulcus
Parietal lobe
Cortical region hidden within depths of lateral (sylvian) fissure: covered by frontal, temporal, parietal opercula
Insula
Primary motor cortex
Precentral gyrus
Anterior to the precentral gyrus
Premotor cortex
Primary somatosensory cortex
Post central gyrus
Lies posterior to the postcentral gyrus
Superior and inferior parietal lobules
Lateral precentral gyrus
Head/face
Medial precentral gyrus
Legs/feet
Inferior postcentral gyrus
Face, tongue, lips
Superolateral postcentral gyrus
Trunk, upper limb
Medial postcentral gyrus
Lower limb
Lies at the end of sylvian fissure
Supramarginal gyrus
Ventral to supramarginal gyrus
Angular gyrus
Medial surface of parietal lobe
Precuneus
Primary visual cortex
Medial occipital lobe
Primary auditory cortex
Superior temporal gyrus
Part of temporal lobe that connects with auditory, somatosensory, visual association pathways
Middle temporal gyrus
Higher visual association area
Inferior temporal gyrus
Includes the major subdivisions of limbic system
Parahippocampal gyrus on medial surface and merges into uncus
Somatosensory function that lies in the floor of sylvian fissure, overlapped by frontal, temporal and parietal operculae
Insula
Limbic system
Subcallosal, cingulate, parahippocampal gyri
Covers base of frontal lobe
Orbital gyri
Covers base of frontal lobe medially
Gyrus rectus
Olfactory bulb lies in
Olfactory sulcus
White matter tract fibers
Association fibers
Commissural fibers
Projection fibers
White matter tract fiber that interconnect different cortical regions in same hemisphere
Association fiber
Long association fiber which lies beneath cingulate gyrus
Cingulum
What matter fiber that interconnect similar cortical regions of opposite hemisphere
Commissural fibers
Largest commissural fiber that links cerebral hemispheres
Corpus callosun
White matter fiber that connects cerebral cortex with deep nuclei, brainstem, cerebellum, spinal cord
Projection fibers
Major projection fiber
Internal capsule
Basal ganglia contains
Globus pallidus, putamen, caudate nucleus
Paired nuclear complexes, serves as relay station for most sensory pathways
Thalamus
White matter is best imaged with
Diffusion tensor imaging (DTI) on 1.5 or 3 tesla
Limbic system best evaluated with
High res coronal T2 MR, T1 volume images and FLAIR
Best evaluates cerebral hemispheres, basal ganglia and thalami
Multiplanar MR
Helpful for evaluation of supratentorial disease processes
Diffusion imaging
Parts of corpus callosum
Rostrum
Genu
Body
Splenium
Projection fibers from internal capsule that fans out and represent all cortical areas
Corona radiata
Major conduit of fibers to/from cerebral cortex
Internal capsule
Anterior limb of internal capsule contains
Frontopontine fibers, thalamacortical projections
Genu of internal capsule contains
Corticobulbar fibers
Posterior limb of internal capsule contains
Corticospinal tract, upper limb-anterior, trunk and lower limbs-posterior
Major efferent projection fibers that connect motor cortex to brainstem, spinal cord, converge into corona radiata, continue thru posterior limb of internal capsule to cerebral peduncle and lateral funiculus
Corticospinal tract
Major efferent projection fibers connect motor cortex to bs and sc and converge into corona radiata to genu of internal capsule to cerebral peduncle, terminate in motor cranial nerve nuclei
Corticobulbar tract
Motor information to pons
Corticopontine tract
Connects entire cerebral cortex with isotopic location in thalamus
Corticothalamic tract
Myelination pattern
Inferior to superior
Central to peripheral
Posterior to anterior
Fully myelinated white matter appear what on T1 and what on T2WI
Hyperintense on T1
hypointense on T2WI
In white matter maturation:
T1:W1 is most useful at what age
Up to 6 months
In white matter maturation: T2 is most useful at what age
After 6 months
Subcortical nuclear masses in inferior hemispheres, involved in motivation and controlling movement
Basal ganglia
Lentiform nucleus include
Globus pallidus and putamen
Corpus striatum include
Caudate nucleus, putamen, globus pallidus
Neostriatum include
Putamen and caudate
Paired ovoid nuclear complexes that relay stations for most sensory pathways
Thalamus
Complex region of nuclear masses ; relay stations for most sensory pathways
Thalamus
Complex region of nuclear masses, fiber tracts that plays major role in normal basal ganglia function
Subthalamus
Basal ganglia consist of
Caudate nucleus, putamen, globus pallidus
Separates caudate head from putamen and GP
Anterior limb of internal capsule
Separate thalamus from basal ganglia
Posterior limb of internal capsule
C-shaped curved nucleus with large head, tapered body, down-curving tail
Caudate nucleus
Deep groove of caudate nucleus that separates caudate from thalamus; its stria terminalis lies deep to ependyma, helps form choroid fissure
Sulcus terminalis
Which has higher myelin content, GP or putamen
GP
Putamen is separated by
Lateral (external) medullary lamina
GP has two segments separated by internal medullary lamina, which are
Lateral (external)
Medial (internal) segments
Ovoid nucleus that extends from Foramen of monroe to quadrigeminal plate of midbrain
Thalamus
Thalamus is subdivided to
Nuclear groups
Geniculate nuclei
Pulvinar
Part of visual system, that is ovoid ventral projection from posterior thalamus
Lateral geniculate nucleus
Part of auditory system that is medial to lateral geniculate nucleus along posterior thalamus
Medial geniculate nucleus
Occupies caudal third of thalamus and overhangs superior colliculus
Pulvinar
Also called interthalamic adhesiom that connects thalami across third ventricle
Massa intermedia
Lens-shaped, lies superolateral to red nucleus
Subthalamic nucleus
Lamella that wraps around lateral thalamus, separated from it by external medullary lamina
Reticular nucleus
Vascular supply of basal ganglia
Mostly lenticulostriate arteries
Vascular supply of thalamus
Thalamoperforators from posterior communicating, basilar, P1 posterior cerebral arteries
Large thalamoperforator that may supply bilateral medial thalami
Artery of Percheron or paramedian thalamic artery
Most common location affected by hypertensive hemorrhage
Putamen
Most sensitive area of brain to hypoxia
Globus pallidus and hippocampus
Common location for strokes, particularly lacunar infarcts and hypertensive hemorrhages
Basal ganglia
Phylogenetically older cortex that has a major role in memory, olfaction, emotion
Limbic lobe
Formed by nestes “C-shaped” arches of tissues surrounding diencephalon, basal ganglia
Limbic lobe
Largest arch of limbic system
Outer arch
Anterior end of parahippocampal gyrus
Uncus
Swings medially at posterior temporal lobe and becomes isthmus of cingulate gyrus
Parahippocampal gyrus
Anterosuperior continuation of parahippocampal gyrus
Cingulate gyrus
Anteroinferior continuation of cingulate gyrus
Subcallosal (paraolfactory area)
Arch of limbic lobe that extends from temporal to frontal lobes, comprised of: Uncus Parahippocampal gyrus Cingulate gyrus Subcallosal
Outer arch
Arch of limbic lobe that extends from temporal to frontal lobes comprised of: Hippocampus Dentate gyrus Supracallosal gyrus Paraterminal gyrus
Middle arch
A thin strip of gray matter that extends from dentate/hippocampus all the way around corpus callosum to paraterminal gyrus
Supracallosal gyrus
Smallest arch of limbic lobe that extends from temporal lobe to mamillary bodies.
Comprised of fornix, fimbria
Inner arch
Curved structure on medial aspect of temporal lobe that bulges into floor of temporal horn
Hippocampus
Three anatomic subdivisions of hippocampus
Head (pes hippocampus)
Body
Tail
Zone in Ammon horn (hippocampus proper) that is composed of Small pyramidal cells that is most vulnerable; commonly affected by anoxia, mesial temporal sclerosis
CA1 (sommer sector)
Primary efferent system from hippocampus
Fornix
Large complex of gray nuclei medial to uncus, just in front of temporal horn of lateral ventricle
Amygdala
Major efferent of amygdala
Stria terminalis
Incomplete fusion of hippocampal sulcus that becomes CSF containing cysts along medial hippocampus are normal or abnormal?
Normal variant
Concave midline depression in basisphenoid
Sella
Anterior borders of sella
Tuberculum sellae, anterior clinoid processes of lesser sphenoid wing
Posterior borders of sella
Dorsum sellae, posterior clinoid processes
Covers sella
Diaphragma sellae
80% of hypophysis
Adenohypophysis
Includes para anterior (pars distalis or glandularis), pars intermedia, pars tuberalis
Secretes somato-, lactogenic, other hormones
Adenohypophysis
Vascular supply of adenohypophysis
Portal venous via hypothalamus
<5% of pituitary, located between AH/NH, contains axons from hypothalamus
Carries releasing hormones to AH, NH
Pars intermedia
20% of pituitary and includes pars posterior (nervosa), infundibular stem, median eminence of tuber cinereum
Neurohypophysis
Contains pituicytes, hypothalamohypophysial tract
Stores vasopressin, oxytocin
Neurohypophysis
Vascular supply of neurohypophysis
Arterial (superior and inferior hypophyseal arteries
Paired, septated, dural-lined venous sinuses that lack valves
Cavernous sinus
Venous tributaries of cavernous sinus
Superior, inferior ophthalmic veins
Sphenoparietal sinus
Contents of cavernous sinus
Venous blood, CN3, 4, V1,V2, V3 and CN6, ICAs and sympathetic plexus
Cranial nerve that lies within superior lateral dural wall
CN3
Cranial nerve that lies within cavernous sinus, next to ICA
CN6
CN that lies just below CN3
CN4
CN found in lateral wall below CN4
V1 ophthalmic division
Most inferior cranial nerve in lateral cavernous sinus wall
V2 maxillary division
Cranial nerve that doesnnot enter cavernous sinus proper (passes from meckel cave inferiorly into foramen ovale)
V3 mandibular branch
Normal size of pituitary in children
< 6 mm
Normal size of pituitary in males
8 mm
Normal size of pituitary in post-menopausal females
8mm
Physiologic hypertrophy of pituitary in young females, what size
10mm
Size of pituitary in pregnant/lactating females
12 mm
Caused by protrusion of arachnoid, CSF into sella, in which normal pituitary becomes flatted, displaced posteroinferiorly against sellar floor
May be associated with pseudotumor cerebri
Empty sella
Can mimic intrasellar aneurysm, compress pituitary
Paramedian ICAs (kissing carotids)
May mimic ICA aneurysm
Anterior clinoid pneumatization
Suprasellar bright spot is usually what
Ectopic neurohypophysis
Less often lipoma
Epiphysis cerebri also called
Pineal gland
Dorsal nuclei of diencephalon
Epithalamus
Major components of pineal region
Pineal gland
Posterior recesses of third ventricle
Internal cerebral veins, vein of Galen, medial posterior choriodal artery
Epithalamus, quadrigeminal plate (tectum), corpus callosum
Dura, arachnoid
Unpaired midline endocrine organ located within quadrigeminal cistern
Pineal gland
Vascular supply of pineal gland
Primarily medial posterior choriodal artery ( lacks blood-brain barrier)
Contents of pineal gland
Pineal parenchymal cells, germ cells, some neuroglial cells (primarily astrocytes)
Function is ro secrete melatonin, thought to regulare sleep/wake cycle, regulation of reproductive function
Pineal gland
Connects habenular, amygdaloid nuclei and hippocampi
Habenular commissure
Connections with dorsal thalamus, superior colliculi, pretectal nuclei and others; medial longitudinal fasciculus fibers also cross here
Posterior commissure
Fibers connecting both habenular nuclei
Stria medullaris thalami
Relay station for olfactory centers, brainstem, and pineal
Habenular nuclei
Connections with hypothalamus, hippocampus, amygdala, brainstem, septal nuclei and stria terminalis
Paraventricular nuclei
Dorsal midbrain or collicular syndrome caused by mass in pineal region compressing tectal plate, with loss of vertical gaze; nystagmus on attempted convergence, pseudo-Argyll-Robertson pupil
Parinaud syndrome
Sudden onser severe headache, visual problems, hemorrhage into pineal cyst or neoplasm
Pineal apoplexy
