372 



THE BRAIN 



wide interval between the medulla oblongata and the 

 posterior part of the inferior surface of the cerebellum. 



The cisterna pontis is the name given to another of the 

 subarachnoideal spaces. It is the continuation upwards, 

 on the floor of the cranium, of the anterior part of the sub- 



Arrow in interventricular foramen 

 Caudate nucleus in right lateral ventricle / 

 Genu of corpus callosum 

 Subarachnoid space 

 Arachnoid membrane 



Fornix 



i Massa intermedia 



arachnoid tissue in tela chorioidea 

 Layers of pia mater of tela chorioidea oi 

 I Supra-pineal recess third vent 



L Pineal body 



Aquaeductus cerebri 

 Lamina quadrigemi 

 (Tectum). The poi 

 crosses the cisU 

 venae magnae cei 



Anterior 

 commiss 

 Cisterna ch 



Optic chiasma 



Hypophysis 



Cisterna 



- 11 "' - s ' -+JF/ / 



,sure^ ' ,' ft 



. s ' X ' ' 



lasmatis ,' V_ ' y I */ yM' 

 ic chiasma / / s\Jk.L ?' '-' / 



Hypophysis / / /* -^ 



interpeduncularis / / , ' 

 Cisterna pontis / / / \ ! 

 Pia mater on pons / / / 



po 



Pedunculus cerebri 

 Posterior commissure 



Fourth ventricle 



"" Cisterna cerebello-medulla 

 Median aperture of 

 fourth ventricle 



FIG. 141. Diagram showing some of the Subarachnoid Cisterns. Dark 

 blue line indicates arachnoid membrane. Pale blue, Subarachnoid tissue 

 containing cerebro-spinal fluid. Dark red indicates cut margin of pia 

 mater. Pale red, surface of pia mater from which arachnoid has been 

 removed. Purple indicates epithelial lining of the cavities of the brain. 



arachnoid space of the spinal meninges. In the region^ of 

 the medulla oblongata it is continuous, on each side, with 

 the cerebello-medullary cistern, so that that subdivision of 

 the brain is completely surrounded by a wide Subarachnoid 

 space. Within the cisterna pontis are the vertebral and 

 basilar arteries. 



