THE VEINS OF THE EAR 657 



(3) The internal cerebral veins [vv. cerebri internae] are two large venous trunks (the venae 

 Galeni) which leave the brain at the transverse fissure, that is, between the splenium of the 

 corpus callosum and the corpora quadrigemina. In this region they unite to form the great 

 cerebral vein [v. cerebri magna, Galeni], which opens into the anterior end of the straight 

 sinus. The internal cerebral veins are formed by the union of the chorioid vein with the vena 

 terminalis near the interventricular foramen. From this spot they run backward parallel to 

 each other, between the layers of the tela chorioidea, and terminate in the way above mentioned. 



Tributaries of the internal cerebral veins.^In addition to the vena terminalis and the chori- 

 oidal, the internal cerebral veins also receive the basal vein, the veins of the thalmus, the 

 vein of the chorioid plexus of the third ventricle, and veins from the corpus callosum, the pineal 

 body, the corpora quadrigemina, and posterior horn of the lateral ventricle. The united 

 trunk, or great cerebral vein, receives veins from the upper surface of the cerebellum, and one of 

 the posterior inferior cerebral veins. 



The chorioid vein [v. chorioidea] runs with the chorioid plexus. It begins in the inferior 

 cornu of the lateral ventricle, and ascends on the lateral side of the chorioid plexus along the 

 margin of the tela chorioidea to the interventricular foramen, where it unites with the vena 

 terminalis to form the internal cerebral vein. It receives tributaries from the hippocampus, 

 corpus callosum, and fornix. 



The terminal vein (or vein of the corpus striatum) [v. terminalis], formed by veins from the 

 corpus striatum and thalamus, runs forward in the groove between those structures, passing 

 in its course beneath the stria terminalis, and joins the chorioid (choroid) vein at the inter- 

 ventricular foramen. Tributaries. — It receives, in addition to the veins from the corpus 

 striatum, thalamus and fornix, the vena septi pellucidi which receives blood from the septum 

 pellucidum, and anterior cornu of the lateral ventricle. 



The basal vein [v. basalis], runs backward over the cerebral peduncle, and enters the 

 internal cerebral vein near the union of that vessel with the vein of the opposite side. 



Tributaries. — A vein, the deep Sylvian, from the insula and surrounding convlutions; the 

 inferior striate veins from the corpus striatum, which they leave through the anterior perforated 

 substance; and the anterior cerebral veins from the front of the corpus callosum. It is also 

 joined by interpenduncular veins from the structures in the interpeduncular space; ventricular 

 veins from the inferior cornu of the lateral ventricle; and by mesencephalic veins from the 

 mid-brain. 



The Cerebellar Veins 



The cerebellar veins are divided into the superior and inferior. 



The superior [vv. cerebeUi superiores] ramify on the upper surface of the cerebellum; some 

 of them run medially over the superior vermis to join the straight sinus and great cerebral 

 vein; others run laterally to the transverse and superior petrosal sinuses. 



The inferior [vv. cerebeUi inferiores], larger than the superior, run, some forward and 

 laterally to the inferior petrosal and transverse sinuses, and others directly backward to the 

 occipital sinus. 



The Veins of the Medulla and Pons 



The veins from the medulla oblongata and the pons terminate in the inferior 

 petrosal and transverse sinuses. 



4. THE VEINS OF THE NASAL CAVITIES 



The venous plexuses on the inferior nasal concha (turbinate bone) and back 

 of the septum are described with the Nose. The veins leaving the nasal cavities 

 follow roughly the course of their corresponding arteries. Thus the spheno- 

 palatine veins pass through the spheno-palatine foramen into the pterygoid plexus; 

 the anterior and posterior ethmoidal veins join the ophthalmic. Small veins 

 accompany branches of the external maxillary artery through the nasal bones and 

 frontal processes of the maxillary bones, and end in the angular and anterior facial 

 veins; and other small veins pass from the nose anteriorly into the superior labial, 

 and thence to the anterior facial. 



5. THE VEINS OF THE EAR 



The veins from the external ear and external auditory meatus join the posterior 

 facial and posterior auricular veins. The veins from the tympanum open into 

 the superior petrosal sinus and posterior facial vein. The blood from the laby- 

 rinth flows chiefly through the internal auditory veins [vv. auditivse internae], 

 which lie with the internal auditory artery in the internal auditory meatus, and 

 enters the transverse or inferior petrosal sinus. Some of the blood from the laby- 

 rinth, however, passes through the vestibular vein which lies in the aquseductus 



