gross topography Flashcards
where does the spinal cord end?
intervertebral disc between L1 and L2
what are the dorsolateral and ventrolateral sulci?
grooves on spinal cord the represent the point of entry of the dorsal roots and exit of the ventral roots respectively
what does the anterior median sulcus contain?
ventral
contains anterior spinal artery
in spinal cord
what is the dorsal median sulcus?
very shallow
what is an ascending tract?
carries information from body up the spinal cord to the brain - in dorsal columns in spinal cord
how are dorsal columns organized?
legs are on either side of dorsal median sulcus
separated from arms by intermediate dorsal sulcus
what do the dorsal columns convey?
vibratory sense, well-localized touch sensation, joint position sense
what are the three parts of the brainstem?
medulla
pons
midbrain
what is the primary fissure of the cerebellum?
deep fold that separates anterior lobe of cerebellum from the posterior lobe
what is the vermis?
medial part of the cerebellum
less prominent than the lateral portions
what are the hemispheres of the cerebellum?
lateral part
what is the flocculus?
two small lobes of cerebellum that are anterioinferior
what connects the cerebellum to the brainstem?
three white matter connections = peduncles
inferior cerebellar peduncle - cerebellum to dorsolateral side of medulla - appears as upward continuation from spinal cord
middle cerebellar peduncle - pons to cerebellum - large bulge in lateral side of brainstem
superior cerebellar peduncles - can’t see without removing cerebellum - cerebellum to midbrain
what are the gracile and cuneate tubercles?
two bumps on medulla on either side of the midline (totals 4 bumps)
gracile is medial, cuneate lateral
represent protuberances overlying nuclei associated with the ascending columns of the dorsal cord
what is the filum terminale interna?
continuation of the pia mater from teh end of the conus medullaris
what is contained in the dorsal funiculus?
dorsal columns
this is between the posterior median septum and the posterior intermediate septum
what is the central canal (in the spinal cord)?
in the connective region between the left and right grey matter
residual of the lumen of the neural tube
what type of neurons are in the ventral horn?
alpha motor neurons - give rise to the alpha fibers innervating muscle
what is the substantia gelatinosa?
most posterior portion of the dorsal horn
because of its appearance using stains for fibers
what is the tuber cinerium?
small prominence running along lateral sides of medulla
over band of trigeminal nerve fibers that run in lateral part of the brain stem
what is the inferior olivary nucleus?
large prominence on ventrolateral part of medulla
what is the postolivary sulcus? which nerves leave the brain from here?
groove located on dorsal side of inferior olive - on medulla
glossopharyngeal (CN IX) and vagus (CN X) nerves leave the brain here
what is the preolivary sulcus? which nerve would you see here?
groove on ventral side of inferior olive on medualla hypoglossal nerve (CN XII) leaves brain here
what are the medullary pyramids? what do they contain? what are they important for?
two long cords running along the length of the brainstem, medially and ventrally
contain bundles of nerve fibers that arise from the cerebral cortex and extend down to spinal cord
critically important for fine and skilled movement
what is the pyramidal decussation?
where the medullary pyramids join (caudal)
where most of the pyramidal nerve fibers cross the midline
defines location of the cervical medullary junction
where is the 4th ventricle?
on the dorsal aspect of the brainstem
begins at middle of medulla and covers rostral medulla and pons
what is the obex?
caudal point of 4th ventricle (diamond)
where central canal of spinal cord opens into ventricular system
what is the stria medullaris?
crosses floor of 4th ventricle
defines division between medulla and pons
what is the sulcus limitans?
longitudinal groove lateral to the midline within 4th ventricle on the medulla and the pons
where is the hypoglossal trigone?
medial to sulcus limitans in the medulla
in 4th ventricle
where is the vagal trigone?
lateral to sulcus limitans in medulla
in 4th ventricle
where is the longitudinal groove?
midline of the 4th ventricle through the medulla and pons
where is the facial colliculus?
medial to the sulcus limitans in the pons
in 4th ventricle
where is the vestibular trigone?
in 4th ventricle on pons lateral to the sulcus limitans
where is the basal pons?
on the ventral side of the pons
what nerves exit the brainstem between the pons and the medulla?
medial to lateral:
abducens
facial nerve
vestibulocochlear nerve
where does the vestibulocochlear nerve travel?
wraps around inferior peduncle with bulge = acoustic tubercle
what is the acoustic tubercle?
bulge in pons/medulla where vestibulcochlear nerve wraps around?
where does the trigeminal nerve travel?
passes through middle cerebellar peduncle
what are the cerebral peduncles?
very large bands of fibers on either side of the midline of the midbrain
contain most of the nerve fibers leaving the cerebral cortex heading for the brain stem or spinal cord
what is the interpeduncular fossa? what nerve would you expect to see here?
impression between the cerebral peduncles in the midbrain occulomotor nerve (CN III) leaves brain here
what are the corpora quadragemina?
four bumps on the surface of the midbrain
consist of the inferior and superior colliculi
what are the inferior colliculi? what process are they important for?
two caudal bumps of the corpora quadragemina on surface of midbrain
deal with hearing
what are the superior colliculi? what processes are they important for?
two rostral bumps of the corpora quadragemina on surface of midbrain
involved in control of eye movement, reflex responses to visual signals and loud sounds
what is the tectum?
another word for the combination of superior and inferior colliculi
what is the brachium of the inferior colliculi?
runs rostrally to inferior colliculi on the lateral side of the midbrain - ends in medial geniculate
where is the medial geniculate?
at lateral end of the brachium of the inferior colliculi
in midbrain
what is the brachium of the suprior colliculi?
runs rostrally to superior colliculi on the lateral side of the midbrain - ends in lateral geniculate
where is the lateral geniculate
at lateral end of the brachium of the superior colliculi
in midbrain
where is the diencephalon?
rostral to the midbrain consists of: - hypothalamus - dorsal thalamus (thalamus) - epithalamus
where are the mammillary bodies?
portion of hypothalamus (of diencephalon)
visible from caudal end
where is the infundibulum?
ventral to mammillary bodies
part of hypothalamus (of diencephalon)
where is the laminal terminalis?
part of hypothalamus
ventral to mammillary bodies
what comprises the stalk of the pituitary?
infundibulum and lamina terminalis
what is the median eminence/tubercinerium? what is it important for?
bump on infundibulum
critical for neuroendocrine control
what does the epithalamus consist of?
pineal gland and habenular nuclei
part of diencephalon
what is the hypothalamic sulcus?
shallow groove that runs from anterior to posterior along the wall of the third ventricle
where is the hypothalamus?
in the diencephalon, caudal to hypothalamic sulcus
where is the massa intermedia/thalamic adhesion?
connection between the two thalami - in third ventricle
where is the stria medullaris thalami?
ridge running from anterior to posterior along the dorsal side of the thalamus
can be traced back to the habenullar nuceli
what is the thalamus important for?
relay site for most of the sensory information including vision and hearing, general somatic sensation
where are the medial and lateral geniculi?
prominences on the dorsal aspect of thalamus just rostral to colliculi of brainstem
chief sites of relay of auditory (MGN) and visual (LGN) info from cerebral cortex
what does the telencephalon consist of?
cerebral hemispheres and basal ganglia
where is the lateral/sylvian fissure?
between the parietal and temporal lobes - visible externaly
where is the insula?
if you peel back the temporal lobe
gyri
aka isle of reil
where is the calcarine sulcus?
from posterior tip of occipital lobe anterior toward parietal lobe
can see in midline cut
gyri on either side receive visual info from LGN
what is the rostrum?
rostral most portion of the corpus collosum
what is the splenium?
dorsal most portion of corpus collosum
what is the genu?
bend in the corpus collosum that connects the rostrum to the body
where is the cingulate gyrus?
follows corpus collosum along dorsal surface
where is the subcallosal region?
directly below rostrum of corpus callosum
in temporal lobe
what is the septum pellucidum?
thin membrane in midline that separates the two lateral ventricles
what is the fornix?
at posterior most portion of septum pellucidum
thickened band
tract that follows lateral ventrical posteriorward and lateralward into temporal lobe
at rostral portion, swings ventralward toward hypothalamus
where and what is the anterior commissure?
near rostral end of fornix
above hypothalamus
tract connecting the two sides of the brain
what is the interventricular foramen of monroe?
where CSF from lateral ventricle can enter the third ventricle
right behind anterior commissure
ventral to fornix
choroid plexus extends through it sometimes
what comprises the floor of the lateral ventricle?
the dorsal surface of the thalamus and the caudate nucleus
where is the stria terminalis?
thin band of fibers in groove between lateral edge of the thalamus and the head of the caudate
where are the transverse gyri (of Heschl)?
on the superior aspect of the temporal lobe - run into the depths of the lateral fissure
