14 Neuroanatomy: Draw It to Know It
Know-It Points
Meninges
■ From outside to inside, the meningeal layers are the
dura mater, arachnoid mater, and pia mater.
■ From outside to inside, the meningeal spaces are the
epidural space, subdural space, and subarachnoid
space.
■ Th e falx cerebri separates the cerebral hemispheres.
■ Th e tentorium cerebelli separates the cerebellum
from the overlying occipital lobes.
■ Th e falx cerebelli separates the cerebellar
hemispheres.
■ Th e superior sagittal dural venous sinus forms within
the falx cerebri.
■ Th e transverse sinuses form within the tentorium
cerebelli.
■ Th e tentorium cerebelli divides the cranial vault into
supratentorial and infratentorial compartments.Cerebrospinal Fluid Flow
■ C e r e b r o s p i n a l fl uid fl ow pattern:
- Th e lateral ventricles empty through the paired
foramina of Monro into the third ventricle. - Th e third ventricle empties into the fourth ventricle.
- Th e fourth ventricle empties down the central
canal of the spinal cord and also through the
foramen of Magendie, in midline, and the foramina
of Luschka, laterally, into the subarachnoid space.
■ Cerebrospinal fl uid is produced and reabsorbed at a
rate of roughly 0.35 milliliters per minute.
■ Th ere is roughly 150 milliliters of cerebrospinal fl uid
in the nervous system at any given time.Cerebral Ventricles
■ Each lateral ventricle has a frontal horn, occipital
horn, and temporal horn.
■ Th e bend of the lateral ventricle is the body.
■ Th e atrium of the lateral ventricle is the confl uence
where the body and the occipital and temporal horns
meet.
■ Th e borders of the fourth ventricle include the fl oor
of the fourth ventricle, the superior medullary velum,
the inferior medullary velum, cerebellar peduncles,
and cerebellum.
■ Choroid plexus lies centrally within the cerebral
ventricles: in the body, atrium, and temporal horn of
the lateral ventricle, third ventricle, and fourth
ventricle.Cisterns, Sinuses, & Veins (Advanced)
■ Collectively, the subarachnoid cisterns at the base of
the brain are referred to as the basal cisterns.
■ Th e notable cisterns are the suprasellar,
interpeduncular, ambient, quadrigeminal,
prepontine, pontocerebellar, premedullary, lateral
cerebellomedullary, and posterior cerebellomedullary
cisterns, and the cistern of the velum interpositum.
■ Th e notable dural venous sinuses are the superior
sagittal sinus, confl uence of sinuses, bilateral
transverse sinuses, inferior sagittal sinus, straight
sinus, and also the sigmoid sinuses, which drain into
the internal jugular veins.
■ Th e notable deep cerebral veins are the vein of Galen,
the basal veins of Rosenthal, and the internal cerebral
veins.
■ Th e superfi cial cerebral veins drain the superfi cial
c e r e b r u m.