840 THE VASCULAR SYSTEM. 
Opening into the superior longitudinal sinus are the superior cerebral veins, and 
it communicates on each side by small openings with a series of spaces in the dura 
mater, the lacune laterales, into which the Pacchionian bodies (arachnoidal villi) 
project. It also communicates, by emissary veins which pass through the foramen 
ezcum and through each parietal foramen (emissarium parietale), with the veins 
on the exterior of the cranium. Its cavity, which is triangular in transverse section, 
is crossed by several fibrous strands called the chord Willisii. 
The inferior longitudinal sinus (sinus sagittalis inferior) hes in the posterior 
Infra-trochlear nerve 
Olfactory bulb 
a ‘a Supra-trochlear nerve 
Oculo-motor nerve 
Optie nerve~ _-Spheno-parietal sinus 
_~Ophthalmie vein 
Optic commissure- y) Anterior clinoid 
; a process 
Anterior cerebral a 
artery—_ [ 
Middle cerebral 
_—Trochlear nerve 
Oculo-motor 
artery eee es 
; ’ nerve 
Posterior ‘ 
comimuni- Abducent ner 
cating artery 
Oculo-motor—_ —Cirecular sinus — 
Ophthal. nerve 
nerve : we 
Posterior cere- eae { 
bralfartery maxillary nerve 
Superior cere- — _Inferior : 
bellar artery | maxillary nerve 
Trochlear | Cavernous sinus 
“ve fill Y | < . \\ asilar sinus — 
nerve ff] |® J _ g \ ~~ Basilar s us ; 
\ % __Gasserian — 
Abducent 2 ganglion : 
nerve Basilar 
mR artery @ 
Inferior 
Trigeminal 
yetrosal 
nerve 
Superior | 
petrosal (| 
sinus 
Facial Agi 
nerve 
Pars inter- ~~ 
media \\ % 
Auditory nerve “ 
\\: 
Glosso-pharyn- 
geal nerve e B X . : 
-neumogastric \ \ % : i 
AN Saale CONN \ o~ a “ yf Lateral sinus 
Spinal accessory nerve 
Sigmoid 
sinus 
~ Tentorium cerebelli 
Hypoglossal nerve ~ (cut) 
Lateral sinus 
Vertebral artery 
Spinal cord “Straight sinus 
1 
. 
; Toreular Herophili 
ey 
. p se = ~ ay" . yy Jine 2] . 
Openings of occipital sinuses Superior longitudinal sinus 
/ 
Falx cerebri (cut) 
Fic. 583.—BasAL BLoop SINUSES OF THE DURA MATER. 
two-thirds of the lower free margin of the falx cerebri. It terminates posteriorly 
by joining with the vena magna Galeni to form the straight sinus. It is cireular 
in transverse section, and it receives tributaries from the falx cerebri and from the 
inner surface of the middle third of each cerebral hemisphere. 
The circular sinus (sinus circularis) is situated in the pituitary fossa, and sur- 
rounds the pituitary body. It is usually formed by anterior (sinus intercavernosus 
anterior) and posterior (sinus intercavernosus posterior) transverse channels which 
pass across the pituitary fossa from one cavernous sinus to the other. 
