1. Ventricles & CSF cisterns

2. Ventricles
CSF filled spaces in the brain related to development of the nervous system as a tubular structure with central canal
Lined with ependyma
Plexuses of highly vascular pia mater form choroid plexuses which produce CSF

3. Lateral Ventricles C-shaped facing anteriorly
Occupy each cerebral hemisphere
Communicates with 3rd ventricle at junction of anterior horn and body – interventricular foramen (of Monro)

4. Lateral Ventricles Anterior horn – within frontal lobe
Anterior: genu corpus callosum
Roof: body corpus callosum
Medial: septum pellucidum
Floor/lateral wall: head of caudate nucleus
Body – within parietal lobe
Lateral wall: body of caudate nucleus
Floor: thalamus (medially)

5. Lateral Ventricles Temporal (inferior) horn Occipital horn (posterior)
Roof: tail of caudate nucleus
Floor: hippocampus
Lateral: tapetum (fibres of corpus callosum)
Anterior: amygdaloid nucleus
Occipital horn (posterior)
Extends from posterior convexity of the “C” – trigone
Lateral: tapetum & optic radiation
Medial: white matter indented by grey matter of calcarine sulcus (calcar avis)

6. Choroid plexus
Composed of invaginated highly vascular pia called tela choroidea
Extends from inferior horn, body into intraventricular foramen and continuous in 3rd ventricle. 4th ventricle also contains a chorioid plexus.
Blood supply
Anterior choroidal (br internal carotid) enters anterior part of temporal horn
Posterior choroidal (br PCA) enters body of lateral ventricle above the thalamus
Venous drainage
Choroidal v in inferior horn, passing anteriorly to intraventricular foramen, joins with thalamostriate v to form internal cerebral v

7. Third ventricle Slit like space between the thalami
Thin anterior wall (lamina terminalis) from anterior commissure superiorly to optic chiasm inferiorly
Inferiorly extension into optic chiasm (supraoptic recess) and infundibulum (infundibular recess)
Posterior extension into pineal stalk (pineal recess) and suprapineal recess above this

8. Third ventricle Anterior: anterior commissure
Roof: anterior commissure, intraventricular foramen, body of the fornix
Floor: structures of hypothalamus incl. pituitary
Lateral: thalami
Thalami are connected across the ventricle in 60% of people by a non-neural connection – massa intermedia

9. Cerebral Aqueduct
Narrow channel passing through brainstem connects posterior end of 3rd ventricle and superior end of 4th ventricle
1.5cm length, 1-2mm diameter
Anterior: cerebral peduncles & tegmentum
Posterior: tectum
Nuclei of CN III, IV, V surround aqueduct

10. Fourth ventricle
Extends as a widening of the aqeduct posterior to the pons to the obex (caudal tip of the fourth ventricle; a marker for the level of the foramen magnum of the skull)
Floor: rhomboid fossa (pons and upper part of medulla)
Roof: cerebellum (superior and inferior medullary vela)
Lateral: cerebellar peduncles
Communicates with the subarachnoid space through
Median aperture (foramen of Magendie) in the inferior medullary vellum open into the cerebellomedullary cistern (cisterna magna)
two lateral foramina of Luschka in the lateral recesses open anteriorly into the pontine cistern

11. Cisterns Collections of deep CSF spaces around the brain
Cerebellomedullary cystern
posterior to medulla and inferior to cerebellar hemispheres
Receives CSF from 4th ventricle via median aperture
Continues as spinal subarachnoid space through foramen magnum
Contents: vertebral a and posterior inferior cerebellar branch
Pontine cistern
Between pons and clivus
Cerebellomedullary cystern above, Interpenduncular cistern below
Contents: basilar artery and assoc branches
Interpenduncular cistern