THE VEINS OF THE HEAD AND NECK 287 



Deep Veins. They finally converge to two trunks, the vena 

 Galeni. These run backward in the velum interpositum, the 

 right and left, lying side by side, and unite into the vena magna 

 Galeni, which joins the straight sinus. Each vena Galeni is 

 formed by the union of the choroid^ vein and the vena corporis 

 striati, and is joined by the basilar and other small veins, while 

 the vena magna receives tributaries from the occipital lobes 

 of each side and from the upper surface of the cerebellum. 



The cerebellar veins are divided into two sets, the superior 

 and the deep. 



The superior join the straight sinus and the vena magna 

 internally, and the superior petrosal and lateral sinuses exter- 

 nally. 



The inferior enter the inferior petrosal, lateral, and occipital 

 sinuses along with branches from the medulla and pons. 



1. The Cranial Sinuses. The superior longitudinal sinus is 

 contained in the upper border of the falx cerebri, and extends 

 from the crista galli to the torcular Herophili. Its section is 

 triangular, and its cavity is crossed by several fibrous bands, 

 the chordae Willisii, and contains some Pacchionian bodies. 

 It grooves the frontal, parietal, and occipital bones. In front 

 a small vein in the foramen cecum connects it with the nasal 

 veins, and through the parietal foramen it communicates with 

 the veins of the scalp. The superior cerebral veins open into 

 the sinus, looking forward contrary to the direction of the blood 

 current. At its termination it enlarges and becomes continuous 

 with the right (usually) or left lateral sinus. From this dilata- 

 tion (the torcular Herophili) a cross-branch passes to join the 

 straight sinus. 



2. The inferior longitudinal sinus, in the lower border of the 

 falx cerebri, runs back to join the straight sinus. 



3. The straight sinus continues the inferior longitudinal along 

 the line of junction of the falx with the tentorium backward, 

 and joins the lateral sinus opposite to that in which the superior 

 longitudinal ends. It receives the vena magna Galeni, some 

 superior cerebellar veins, and a cross-branch from the torcular 

 Herophili. 



4. The lateral sinuses run in the attached margin of the ten- 

 torium from the internal occipital protuberance to the jugular 

 foramen, grooving, in order, the occipital, parietal, mastoid 

 portion of the temporal and the occipital a second time. Each 



