Download Neuroscience - Lab Practical

Neuroscience - Lab Practical
 Lab 1
○ Objectives
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Indicate standard anatomical directions and planes of section
Describe and identify the major regions of the cranial portion of the central nervous system
Identify the layers of meninges and locate the major subarachnoid cisterns and arachnoid granulations
Locate the foramina that allow communication between the ventricular system and the subarachnoid space
Identify the major arteries supplying the cranial portion of the central nervous system and identify/describe the areas
supplied by each
 Locate cerebral veins and describe how in life they connect to the dural sinuses
 Point out the lobes of the cerebrum
 Identify the major gyri and sulci of the cerebral hemispheres
○ General Topography
 Telencephalon - cerebral hemispheres
 Brainstem = medulla + pons + midbrain (2-22)
 Continuous with spinal cord
 medulla oblongata - myelencephalon
 pons - superior to medulla
 midbrain - between pons and cerebrum (folded under in the cephalic flexure)
 Ventral Aspect of Cerebrum (2-14 & 2-20 & 2-22)
 longitudinal fissure
 olfactory bulb and olfactory tract (divides into medial and lateral olfactory stria)
 anterior perforated substance - at end of olfactory tract, deep in sulcus
○ many aterial branches penetrate deep brain structures in this region
 optic nerve - CNII is at this same level (at end of olfactory tract)
○ optic chiasm and optic tracts
 medial eminence of the hypothalamus - posterior to the optic chiasm, low rounded midline
elevation
○ infundibulum of the hypophysis cerebri - (ie. stalk of the pituitary since hypophysis cerebri
means pituitary) extends from the medial eminence
 mammillary bodies - posterior to median eminence on either side of midline (they are brain boobs)
○ part of the hypothalamus
○ Meningeal Relationships, Venous Sinuses, Cisterns and Ventricles
 Dura mater - protects brain and spinal cord and is composed of two layers
 Periosteum - outer
○ dural venous sinuses - between meninges and periosteum
 Meninges - inner and create the
○ falx cerebri - divides left and right hemispheres of the cerebellum
○ tentorium cerebelli - divides cerebrum from cerebellum
 divides cranial cavity into the larger supratentorial compartment and the smaller infratentorial
compartment
 midbrain passes through the tentorial notch/incisure
○ falx cerebelli - divides left and right hemispheres of the cerebellum
 arachnoid mater  subarachnoid space - CSF filled space
 arachnoid mater doesn’t follow contours of brain exactly, so spaces, called cisterns are created
○ in CT scan blood is white and CSF is black
○ Important Cisterns (2-30)
 Cisterna magna - (cerebellomedullary cistern) - inferior surface of cerebellum and dorsal
aspect of medulla
 Pontine cistern - inferior aspect of pons and the midline groove of the pons for the basilar
artery
 interpeduncular cistern - interpeducular fossa between the cerebral peduncles
 optic cistern - region of the optic chiasm
 callosal cistern  superior cistern  lateral cistern - above lateral fissure
 each cerebral sulcus forms a small cistern due to overlying arachnoid
 pia mater - vascular layer on external surface of neural tissue
 CSF
 choroid plexus - makes CSF, found in ventricular system
○ lateral ventricle → third ventricle → cerebral aqueduct → fourth ventricle
 CSF released from fourth ventricle to subarachnoid space at
○ Foramen of Magendie - a median aperature
 Opens in the inferior medullary velum
○ Foramen of Luschka - two lateral aperatures
○ Tufts of choroid plexus can be found around these foramen
 CSF returned to blood through arachnoid granulations/ pacchionian bodies
○ Located in dural venous sinuses and the blood goes to superior saggital sinus (which goes along
longitudinal fissure)
○ Vascular Supply
 Arteries on the surface of the brain are in the subarachnoid space because they are cerebral arteries
 Blood supplied to brain via
 internal carotid arteries anterior circulation
 vertebral arteries - posterior
circulation
 Circle of Willis - joins the anterior
and posterior circulation of the brain
 Anterior Circulation (2-21)
 Anterior cerebral artery (ACA)
 Anterior communicating artery
 Middle cerebral artery (MCA)
 Anterior choroidal artery (often
derives from int. carotid artery)
 Posterior Communicating
Artery (PCA)
 Posterior Circulation (2-21)
 Anterior spinal arteries - goes
down midline
 Posterior spinal arteries
 Posterior inferior cerebellar
arteries (PICA)
 From Basilar Artery
○ Anterior inferior cerebellar
artery (AICA)
○ Superior cerebellar arteries
○ Posterior cerebellar arteries
 Cerebral Veins
 Thin walled
 Traverse the subarachnoid space and penetrate through the arachnoid membrane
 great cerebral vein (of Galen) - (H-28) collects veinous drainage from many central structures
○ originates at splenium of corpus callosum and cerebellum and becomes straight sinus in
tentorium cerebelli then connects to superior saggital sinus near cerebellum
○ Transection of Brainstem and Hemisection of Forebrain
 Brainstem
 crus cerebri/cerebral peduncles
 interpeduncular fossa between the two cerebral peduncles
 oculomotor nerves (CNIII) emerge from interpeduncular fossa
 Topography of the Cerebral Cortex
 lateral/Sylvian fissure - separates the temporal lobe
○ insula is inside
 precentral sulcus  precentral gyrus - motor cortex
 central sulcus/fissure - boundary between frontal and parietal lobe
 postcentral gyrus - sensory cortex
 postcentral sulcus  corpus callosum - contains large commisure fibers
 parieto-occipital sulcus - visible medially, divides parietal and occipital lobes
 parieto-occipital notch  Frontal Lobe
○ Medial Surface (H-26)
 Callosal Sulcus - just above the corpus callosum
 cingulate gyrus and the cingulate sulcus just above it
 anterior portion of paracentral gyrus/lobule - a medial continuation of the precentral gyrus
○ Inferior Surface
 olfactory sulcus - where the olfactory tract lays
 gyrus rectus (rectus = straight) - medial to olfactory tract
 Parietal Lobe
○ Lateral Surface (2-11)
 Supramarginal gyrus - caps the lateral fissure
 Angular gyrus - caps the superior temporal sulcus
○ Medial Surface (2-26)
 Posterior portion of paracentral gyrus/lobule - a medial continuation of postcentral gyrus
 Precuneus - area superior and rostral to parieto-occipital sulcus
 Occipital Lobe (2-26)
○ Cuneus - area between parieto-occipital sulcus and calcarine fissure
○ Calcarine fissure - connects to parieto-occipital sulcus
○ Lingual gyrus - area below calcarine fissure
 Temporal Lobe
○ Lateral (2-11)
 superior, middle and inferior temporal gyri - parallel to lateral fissure
 superior and inferior temporal sulci - in between the gyri
○ Open lateral fissure - transverse temporal gyri flows into limbic area
○ Medial and inferior (2-26 and 2-14)
 parahippocampal gyrus and uncus
 collateral sulcus - separates parahippocampal gyrus
 Lab 2
○ Objectives
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Recognize the spinal level of cross-sectional views of spinal cord segments
Identify key internal spinal cord structures
Describe the spinal cord arterial supply and territory subserved by anterior and posterior circulations
Identify primary spinal cord sulci and fissures, such as those associated with the midline and separating the two dorsal column fasciculi
Identify the major fissures and lobes of the cerebellum
Identify the deep cerebellar nuclei, specifically the dentate nucleus
Identify the cerebellar peduncles and their attachments to the brainstem
Identify key landmarks on the surface of the floor of the 4th ventricle and tissues forming the other boundaries to this ventricle
Identify the attachment points of cranial nerves III-XII
Identify surface features representing spinal and medullary sensory tracks and nuclei (gracilis, cuneatus, trigeminal) and motor tracts
(crus cerebri, pyramids, pyramidal decussation)
Identify other surface features of the brainstem
○ External Features of Dorsal Brainstem (2-31)
 Corpora quadrigemina - forms roof of midbrain
 Superior colliculus - eye movement and targeting
○ brachium of superior colliculus - lateral white matter tract connecting it to the hypothalamus
 an extension of the optic tract
 Inferior colliculus - auditory system center
○ brachium of inferior colliculus - lateral white matter tract connecting it to the hypothalamus
 an auditory projection to the medial geniculate nucleus
 Superior medullary velum - thin sheet of grey matter extending from inferior colliculus to base of
cerebellum forming the roof of the 4th ventricle
 Trochlear nerve - CN IV, originates just below inferior colliculus (only dorsally originating CN)
 cuneate fasciculus → gracile faciculus → postero-median sulcus → repeat backwards
 trigeminal tubercle/nucleus - lateral to cuneate fasciculus and is long and skinny
 note this is a nucleus that is long
○ Morphology of the Cerebellum (2-36)
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Has lots of deep sulci and small gyri called folia
Vermis - area the connects the two hemispheres of the cerebellum (on inferior surface??)
Cerebellar peduncles (superior, middle and inferior) - connect cerebellum to midbrain
Medial View
 anterior lobe → primary fissure → posterior lobe → posterolateral fissure → flocculonodular
lobe
 Deep cerebellar nuclei (cross section)
 dentate nucleus (5-16) - irregular C or U shaped stripe of grey matter (squiggly)
 interpositus nucleus (interpost) - made of globose and emoliform nuclei
○ between dentate nucleus and fastigial nucleus
 fastigial nucleus - (6-16) innermost and medial
○ Dorsal Brainstem/Floor of 4th Ventricle (2-31)
 Boundaries of 4th ventricle
 Lateral boundaries - superior cerebellar peduncles rostrally and inferior peduncles caudally
 superior medullary velum - forms rostral roof
 inferior medullary velum - forms caudal roof
 Striae medullares - dorsal view of brainstem, white fiber strand bumps that help connect brainstem to
cerebellum
 vestibular area - just above the striae medulares?? and lateral to the facial colliculus
 facial colliculus - a pair of medial bumps at same level as inferior cerebellar peduncle and just above
striae medullares where the nerve fibers of the facial nucleus pass over the abducens nucleus
 hypoglossal triangle - a pair of vertical columnar bumps along the midline inside 4th ventricle
 vagal triangle - a pair of vertical columnar bumps lateral to the hypoglossal triangles
 dorsal nucleus of the vagus nerve - is below vagal triangle
○ Ventral Brainstem (2-20, 2-21)
 Cerebral peduncles - the main structures of the pons, fibers go laterally and connect to middle
cerebellar peduncle
 anteromedian sulcus - midline grove of ventral brainstem
 pyramids - vertical ridges of white matter (containing pyramidal axons) along either side of the
anteromedian sulcus at the medulla
 decussation of the pyramids - an inch below pons the pyramidal cell axons decussate
 inferior olive - vertically oriented oval white matter eminence lateral to the pyramids (and closer to
the pons)
○ Identification of Cranial Nerve Roots
 CN III - Oculomotor Nerve - comes out near midline just above pons at interpeduncular fossa
 CN IV - Trochlear Nerve - only CN to come from dorsal midbrain, thin, curves around to ventral
side just above mid pons
 CN V - Trigeminal Nerve - fat nerve that comes out of lateral mid-pons
 Bigger part is the sensory root and the smaller part is the motor root
 CN VI - Abducens Nerve - thin nerve that comes out of medial junction of pons and medulla
 CN VII & VIII - Facial and Vestibulocochlear Nerves - both come out of the lateral junction of
pons and medulla, with the facial nerve exiting more medially
 cerebello-pontine angle - where pons, medulla and cerebellum meet??
 intermediate nerve - sensory root of the facial nerve (in between CN VII and CN VIII)
 CN XII - Hypoglossal Nerve - rootlets from the inferior olive make this nerve
 CN IX, X, XI - Glossopharyngeal, Vagus and Accessory Nerves - dorsolateral to the inferior olive
there are a bunch of rootlets and the top little bit make IX, the middle bunch make X and the long
group of diffuse rootlets below make XI
○ The Spinal Cord
 Gross Anatomy (2-1)
 Denticulate ligament - anchors the spinal cord to the dural covering
 conus medularis - cone-shaped taper of the spinal cord in upper lumbar region
 filum terminale - extension of the pia matter from conus medularis to coccygeal region to anchor
 cauda equina - horse tail
 Posterior view - can see two posterior spinal arteries along origins of roots
 Anterior view - can see one anterior spinal artery along midline at anterior median fissure
 Cross Section
 substantia gelatinosa - lamina II (near dorsal side) of grey mater (it is a little lighter??)
 seen only at thoracic levels and upper lumbar sections
○ nucleus dorsalis/Clarke’s Nucleus - a dark nucleus the supplies proprioception info to
cerebellum
○ intermediolateral (lateral) cell column - little bump in grey matter for intermediate horn?
 White Columns/funiculi - posterior (dorsal), lateral and anterior (ventral)
 Differential Morphology of Cross Sections
○ Note - location of central canal moves
○ Note - size and shape of posterior column changes
○ Cervical Enlargement (C7) - not round
 There is a septum/sulcus between the fasciculus gracilis and fasciculus cuneatus
 Largest since all descending and all ascending tracts must pass through it
○ Thoracic - More rounded, and a lot less grey mater
○ Lumbar - Round and more grey mater than thoracic due to the lumbar enlargement, also less
white matter since it is leaving
○ Sacral - Mainly grey mater
○ Coccygeal - even less white matter
 Self-Study (Internal Structure of the Brainstem)
○ 40% of practical exam will consist of brainstem and spinal cord sections
○ Lower Medulla (6-8 and 6-9)
 gracile fasciculus and gracile nucleus on dorsal midline
 cuneate fasciculus and cuneate nucleus lateral to that
 fibers from these nuclei can be seen decussating ventrally in the internal arcuate fibers
 after crossing, the fibers form a tract called the medial lemniscus which can be seen rostrally to the
level of the internal arcuate fibers
○ medial lemniscus - white matter that is either along midline or lateral to pyramidal decussation
 pyramidal decussation - fibers that decussate more caudal to the level of the internal arcuate fibers
 pyramid tracts - white mater ventral to these decusations
 spinal trigeminal nucleus - large mass of grey mater on lateral most portion of brainstem
 spinal trigeminal tract - white mater lateral to the spinal trigeminal nucleus
○ Mid to Upper Medulla (6-10 and 6-11)
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olivary nucleus - is squiggly and on ventrolateral edges
spinocerebellar tract - white mater on lateral edge of middle
inferior cerebellar peduncles (restiform bodies) - large white mater area pointing out dorsolaterally
hypoglossal nucleus (CN XII) - near dorsal midline
dorsal motor nucleus of the vagus nerve (CN X) - just lateral to hypoglossal nucleus
nucleus ambiguous - difficult to find???
vestibular nuclei - (nucleus for CN VIII) nuclei at dorsal most extent
tractus solitarius - (solitary tract, formed by CN VII, IX, and X) surrounds the nucleus of the solitary
tract
 solitary tract nucleus - just a little ventral to the vestibular nuclei and very easy to spot
○ Ponto-Medullary Junction and Inferior Pons (6-12 to 6-17)
 This is the exit site of CN VI, VII and VIII thus the nuclei associated with these can be seen just
rostrally to this level
 vestibulocochlear nuclei (CN VIII) - separated into the vestibular nuclei and the dorsal and
ventral cochlear nuclei
○ dorsal and ventral cochlear nuclei are separated from the vestibular nuclei by the restiform body
 abducens nuclei (CN VI) - close to midline and fourth ventricle
 facial nuclei (CN VII) - lateral and midway down section?
○ facial colliculus - ???
○ Mid and more Rostral Pons (6-17 - 6-21)
 Identifiable because there are lots of transverse fibers in ventral brainstem (these connect laterally to
the middle cerebellar peduncle??)
 superior cerebellar peduncle - at top???
 pontine nuclei - grey mater ventral to the transverse fibers
 Components of trigeminal system (6-19)
 principle sensory nucleus of trigeminal nerve - just ventral to superior cerebellar peduncle and
lateral
 motor nucleus of trigeminal nerve - just medial to sensory nucleus
 Medial Lemniscus - horizontal flat band of white mater above pontine nuclei
 Changes shape with section, and very visible because it has lots of myelin
 trapezoid body - in between medial lemniscus and pontine nuclei
 Lateral Lemniscus - smaller and lateral to medial lemniscus
 Changes shape with section
 locus ceruleus - important nucleus of norepinephrine containing neurons
 6-20 near fourth ventricle??
○ Midbrain (6-22 - 6-25)
 Midbrain is organized into two layers the tectum (dorsal) and the tegmentum (ventral)
 The cerebral aqueduct divides the two layers
 Tectum contains the superior and inferior colliculi and the associated fiber tracts
 Tegmentum contains lots of other stuff
○ Together with crus cerebri the tegmentum makes up the cerebral peduncle
 Here the cerebral peduncles connect and decussate forming the decussation of the superior
cerebellar peduncles (easy to spot because there is tons of myelin)
○ Fibers from each peduncle then terminate in red nucleus more rostrally (6-25)
 Be able to identify these in each section: corpora quadrigemina (inferior and superior colliculi),
cerebral aqueduct, medial lemniscus (at outer edges?) then the red nucleus, substantia nigra (at
level of red nucleus) and the crus cerebri where possible
 You can kinda see layers of white and grey mater in the superior colliculus
 Oculomotor nuclei (CN III) - medial structure, ventral to central aqueduct, at level of
interpeduncular fossa
 Edinger-Westphal Nucleus - dorsomedial and connecting to oculomotor nuclei
 Trochlear nuclei (CN IV) - ???
 Medial longitudinal fasciculus - small, compact bundle of white mater that extends throughout the
length of the brainstem and interconnects motor nuclei for eye movements to produce coordinated
eye movements
○ Just lateral to the oculomotor nuclei
 Brainstem Anatomy Workshop
○ Neuroaxis - axis of the CNS going from forhead to spinal cord
 Right angle turn - cervical flexure
○ SEE SHEET for external features of brainstem regions
 Peduncle means “stem”
 You can’t really see the pyramidal decussation
 Obex - closure of 4th ventricle, on dorsal surface of medulla, caudally
○ 3 Main Internal Regions of Brainstem
 SEE SHEET
 Olivary nucleus indicates you are at the medulla
○ Internal Structures of the Brainstem
 Descending Motor Structures
 She didn’t do the bolding here
 Corticospinal System
○ Pathway = primary motor cortex (which is an upper motor neuron) → internal capsule →
cerebral peduncle/crus cerebri in midbrain → corticospinal tract in (ventral) pons → pyramid
in medulla → pyramidal decussation in medulla → corticospinal tracts in spinal cord →
ventral horn of spinal cord (which is a lower motor neuron)
○ Basically stays in ventral aspect of brainstem
 Ascending Sensory Structures
 Spinothalamic/anterolateral tract - sends info about pain and temp
○ Pathway = sensory neuron → DRG → dorsal horn ganglion → decussation to anterior column
→ ascends via lateral spinothalamic tract in medulla, pons and midbrain → ventral
posterolateral nucleus (VPL) in thalamus → internal capsule → sensory cortex
○ Basically stays in anterolateral aspect of brainstem the whole time up
 Dorsal Columns - send info about proprioception and discriminatory touch
○ Pathway = sensory neuron → DRG → posterior (dorsal) column → cuneate and gracile
nucleus → decussation at the internal arcuate fibers in medulla → now ascends via medial
lemniscus (which is more in the middle of from dorsal to ventral) → medial lemniscus changes
position to more horizontal by the time it gets up to the midbrain → ventral posterolateral
nucleus of thalamus (VPL) → internal capsule → sensory cortex
○ Basically begins dorsally then goes to the middle
 Cranial Nerve Nuclei (Memorize whether each nuclei is in midbrain, pons or medulla)
 Midbrain
○ Can tell the two apart by looking for red nucleus (indicates oculomotor nucleus)
○ III - Oculomotor
 Both at level of superior colliculus
 Motor - occulomotor nucleus - medial and below cerebral aqueduct, fibers pass through red
nucleus
 Parasympathetic - Edinger-Westfall Nucleus - medial and below cerebral aqueduct, fibers
pass through red nucleus
○ More ventral than the occulomotor nucleus
○ IV - Trochlear
 Motor - trochlear nucleus - at level of inferior colliculus
○ In about the same spot as occulomotor nuclei, just more caudal
○ Axons swing around central aqueduct, decussate and exit dorsally
 Pons
○ V - Trigeminal
 Motor - motor nucleus of V - at level of middle cerebral peduncle, but medial to it
 Sensory - (pontine) primary sensory nucleus - in between middle cerebral peduncle and
motor nucleus of V
 Sensory - spinal trigeminal nucleus - from pontine nucleus down to medulla
○ VI - Abducens
 Motor - abducens nucleus - very dorsomedial in basal portion of pons?
○ VII - Facial
 Motor - Facial Motor Nucleus - at same level as abducens nucleus, but more ventral (in
center of section
○ Axons travel up and around the abducens nucleus (to make the genu of the facial nerve)
then back down and out ventrally
 Parasympathetic - superior salivatory nucleus - just dorsomedial to facial motor nucleus
 Sensory - ??
 Medulla
○ VIII - Vestibulocochlear - is in medulla even though it comes out right next to facial nerve
○ IX, X, XI (motor)
○ IX - Glossopharyngeal
 Motor - nucleus ambiguous - ??
 Sensory (pain and temp) - spinal nucleus of V - ??
 Special Sense (taste) - solitary nucleus - ??
○ Note that taste info from VII, IX and X all goes to gustatory nucleus, which is rostral end
of solitary nucleus
○ IX - Accessory Nerve
 Motor - nucleus ambiguous ○ X - Vagus Nerve
 Same nuclei as glossopharyngeal??
○ XII - Hypoglossal Nerve
 Motor - hypoglossal nucleus - dorsomedial
 Lab 3
○ Objectives
 Identify the principle components of the basal ganglia and other deep cerebral nuclei
 Caudate nucleus (head, body & tail), putamen, globus pallidus (internal and external segments), substantia nigra,
amygdala, claustrum, red nucleus
 Identify key anatomical structures of the diencephalon including
 Boundaries of the thalamus and hypothalamus, stria medularis, anterior nucleus of the thalamus, lateral and medial
geniculate nuclei, pulvinar, mammillary bodies, pineal body
 Identify the hippocampus and alveus, fimbria, and fornix (crus, body and columns)
 Identify the ventricles of the forebrain and points of interventricular communication
 Identify forebrain commissures (anterior, posterior and corpus callosum with its subdivisions) and other key white matter
structures (corona radiate, anterior and posterior limbs of the internal capsule, external and extreme capsules and crus
cerebri)
○ Subcortical Structures on the Medial Cerebral Surface
 Corpus Callosum
 Splenium (posterior end), body, and genu (anterior end)
 septum pellucidum is a thin translucent lamina of grey matter below the corpus callosum
○ separates the anterior horns of the lateral ventricles
○ body of fornix - create lower boundary of septum pellucidum
 Diencephalon
 Is between the cerebrum and midbrain
 Consists of thalamus, subthalamus, hypothalamus and epithalamus
 Boundaries
○ Medial - third ventricle
○ Rostral - lamina terminalis
○ Superior - lateral ventricle, fornix
○ Inferior - floor of the lateral ventricle (optic chiasm, median eminence???, mammillary bodies
and posterior perforated substance)
○ Lateral - internal capsule
○ Posterior - posterior commisure
 pineal body (epiphysis) - just above the posterior commisure and connected via the pineal recess
 choroid plexus in the third ventricle
 Foramen of Monroe (interventricular foramen) - connects lateral ventricle to third ventricle,
located in medial fornix
 Rostral Wall
○ Column of Fornix - descending right near interventricular foramen
○ anterior commisure - just inside the columns of fornix
 white fiber bundle containing commissural fibers connecting temporal lobes
○ lamina terminalis - just below the anterior commisure down to optic chiasm
 Inferior Wall
○ optic recess - a small ventricular cavity above the optic chiasm
○ infundibular recess - a small ventricular cavity below the optic chiasm
○ infundibulum (hypophysial stalk) - little pointy thing near infundibular recess
 hypothalamic sulcus - follows path of interventricular foramen to cerebral aqueduct
○ separates the thalamus (above) from the hypothalamus (below)
 massa intermedia - connects to right and left thalami (not a commissure though)
 stria medularis thalami - upper border of thalamus, narrow ridge of white matter carrying info
from limbic system???
 posterior hypothalamus - from mammillary bodies posterior
 anterior hypothalamus - in front of mammillary bodies
○ Internal Structure of the Cerebrum
 Coronal Slices
 Corpus Striatum - composed of caudate nucleus, lentiform nucleus, claustrum and amygdaloid
nucleus
 Diencephalon - epithalamus (containing pineal, posterior commissure, and stria medularis),
thalamus, subthalamus and hypothalamus
 5-1
○ Review - corpus callosum, septum pellucidum, cingulate gyrus, lateral ventricle
○ head of the caudate nucleus - just lateral to the lateral ventricle
○ internal capsule (anterior limb)- white mater strip lateral to caudate nucleus
○ putamen - grey matter nuclei lateral to internal capsule
○ external capsule - white mater lateral to putamen
○ claustrum - thin strip of grey matter lateral to external capsule
○ extreme capsule - white mater lateral to claustrum
○ Insula - in depths of lateral fissure
 5-2 - through anterior commissure and columns of the fornix
○ anterior commissure - horizontal strip of white matter below internal capsule
 inferior to this is the anterior hypothalamus
○ head of caudate nucleus still seen
○ Lentiform Nucleus - now there isn’t just the putamen, there is also the globus pallidus lateral to
the internal capsule
 Putamen - darker and more lateral
 globus pallidus - lighter and more medial
 5-3 - through the optic chiasm and anterior thalamic nucleus
○ head of caudate nucleus - still seen
 if lateral ventricle is butterfly wing-shaped then you are looking at the head, if it is mostly
horizontal then you are looking at the body of the caudate nucleus
○ third ventricle - now visible
○ body of the fornix???
○ Here globus pallidus has internal and external divisions (internal is lower)
○ columns of the fornix - seen medial and below the lateral ventricle
 fornix terminates at mammillary bodies
○ optic tract - ventral most part, near amygdala (but not on temporal lobe)
○ amygdala - medial most region of the temporal lobe (thus more rostral to temporal lobe)
 5-4 - through mammillary bodies
○ Here the caudate nucleus is cut in two places
○ Thalamus - can be seen prominently at midline and contains lots of nuclei
○ internal capsule (posterior limb)
○ hippocampus - can now be seen at medial most region of temporal lobe
 5-5 - just posterior to mammillary bodies
○ posterior limb of internal capsule now
connects to cerebral peduncles via the
basis pedunculi (crus cerebri)
○ substantia nigra - just medial to lower
internal capsule
 contains melanin granules making it
darkly pigmented
○ red nucleus - medial to substantia nigra
○ tail of caudate nucleus - can be seen as
very small sliver of grey mater just above
the hippocampus
○ Fornix
 See picture
 begins at mammillary bodies, ends at hippocampus in the temporal lobes
 alveus - white mater on outer edge that leaves hippocampus and connects fimbria to fornix??
 fimbria - also white mater, extensions of the hippocampus (5-8)
○ A lower lateral extension of the crus of the fornix in the lateral ventricle area??
○ Caudate Nucleus
 See pictures
 5-6 and 5-7 - through the posterior commissure
○ body of caudate nucleus is smaller
○ Thalamic Nuclei
 Pulvinar - up near lateral ventricle
 medial geniculate body - above hippocampus, lateral and
below pulvinar
 lateral geniculate body - above hippocampus, lateral to
medial geniculate body
○ both medial and lateral geniculate bodies seem
disconnected from thalamus since they are surrounded
by white matter
 5-8 - posterior to posterior commissure
○ here you can see the fimbria associated with both the
hippocampus and the fornix
○ pulvinar nucleus can also be seen
○ crus of the fornix seen here since it is posterior
 Horizontal Slices
 Slice 1 - above level of corpus callosum
○ Centrum ovale - made of white matter making many
connections??
○ corona radiata - made of white matter making many connections??
 Just lateral to lateral ventricle
○ caudate nucleus
○ choroid plexus
 5-11 - made through genu and splenium of corpus callosum
○ corpus callosum (genu at top, splenium at bottom)
○ body of fornix - white mater just lateral to septum pellucidum
○ anterior thalamic nucleus - protrusion of grey mater kind of splitting the lateral ventricle
 5-12 - through the foramen of Monro, rostrum of the corpus callosum, crus of the fornix, and
splenium of the corpus callosum
○ grey mater separated into three parts by the internal capsule
 upper third is caudate, lateral third is lentiform nucleus, lower third is thalamus
 anterior and posterior limbs of internal capsule connected by genu of internal capsule
 pulvinar - marks the most posterior portion of the thalamus
○ globus pallidus - inner part of lentiform nucleus
○ putamen - outer part of lentiform nucleus
○ column of the fornix - very medial structure in anterior lateral ventricle, kind of hanging on to
the septum pellucidum
○ crus of the fornix - in posterior lateral ventricle, a horizontal structure hanging out??
 5-13 - through the anterior commissure, posterior commissure and pineal body
○ lateral to putamen
 external capsule → claustrum → extreme capsule
 striatum???
 globus pallidus - external and internal divisions
○ medial geniculate nucleus - above hippocampus
○ lateral geniculate nucleus - lateral to medial geniculate nucleus
 5-14 - through hypothalamus, mammillary body and inferior colliculus
○ book picture doesn’t line up with lab picture
○ internal capsule enters cerebral peduncles
○ substantia nigra can be seen
○ calcarine fissure - ???
○ amygdala - in temporal lobe but above substantia nigra!
○ hippocampus - in temporal lobe, but below substantia nigra
○ dentate gyrus - ??? in the hippocampus, in a deep curl?
○ subiculum - ??? part of the hippocampus that comes out medially?
 Lab 3 Intro
○ Objectives
 Be able to identify the major structures of the forebrain
 Be able to visualize the 3D arrangement of forebrain structures
 Begin to integrate identification of forebrain structures in brain slices and identification of these structures in clinical
images
 Integrate understanding of forebrain structure from this lab and functions of forebrain structures discussed in lecture
○ Forebrain = telencephalon + diencephalon + ventricles
 Connected by corpus callosum, anterior commissure, posterior commissure and hippocampal
commissure
○ Diencephalon structures
 Above hypothalamic sulcus
 Thalamus - contains pulvinar, anterior and lateral & medial
geniculate nuclei
 Epithalamus - contains pineal gland
 Below hypothalamic sulcus
 Hypothalamus - contains infundibulum, median eminence,
mammillary body
 Subthalamus - subthalamic nucleus
 General rule - structures that are medial to the internal capsule
are diencephalic nuclei
 Structures that are lateral to the internal capsule are telencephalic basal ganglia
 The one exception is the caudate nucleus, it is medial, but it is a basal ganglia structure
○ Telencephalic Structures
 Neocortex vs. allocortex
 Corona radiata
○ Fornix - nerve-like bundle of fibers (axons) for communication between the hippocampus, mammillary
body and other forebrain structures
○ Multiple sclerosis - shows up as hyperintesities on MRI
○ Function
 Telencephalon
 Basal Ganglia
○ Caudate, putamen, globus pallidus - work with cortex and cerebellum to coordinate movements
○ Amygdala - contributes to autonomic functions and emotions
 Diencephalon
 Thalamus
○ Contains nuclei by which other parts of the CNS communicate with cortex
○ Contains nuclei that process sensory, motor, limbic, and other info
 Anterior nucleus - processes limbic info
 Pulvinar - processes visual info
 Hypothalamus - contains nuclei that contribute to homeostatic, reproductive, stress, and other functions
 Epithalamus
○ Pineal - regulation of circadian rhythms
 Neuroimaging Workshop
○
Objectives
 To identify different radiologic modalities used in diagnosis and management of neurological disorders
 To correlate anatomic structures with function based on different radiological modalities
 To review common neuroradiological findings of common neurological disorders
○ Things to know about the images
 CT - only one where bone and blood is white
 In T2 MRI, blood vessels are black, CSF is white
 Diffuse weighted imaging (DWI) MRI - picks up edema, which indicates stroke
 Contrast is useful to indicate leakage of blood/brain barrier (tumor, infection)
 On images it is as if you are looking through the feet (so right is left and left is right)
 Always check to see if your image is symmetrical
○ Neurological Disorders
 Hypertensive Encephalopathy
 Subarachnoid hemmorage (can have neck stiffness?)
 Springomyelia - hole in spine due to central aqueduct expanded
 Infections of the CNS show up as hyperintensities on CT
 Herpes Simplex has predisposition to infecting the temporal lobe
 Multiple Sclerosis shows up as hyperinstensities on T1 MRI, with breakdown of blood brain barrier
 Cranial Nerves
vestibulocochlear
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