Axial perspective of the ventricular system. The cerebrum has been sectioned and the corpus callosum removed to allow this view from above into the lateral ventricles. In the lateral wall of the anterior horn of the lateral ventricle is the head of the caudate nucleus. Further posteriorly, the floor of the body of the lateral ventricle is formed by the thalamus, while the lateral wall of the body of the lateral ventricle is formed by the body of the caudate.   The thalamostriate vein courses within the ventricle by running in a narrow groove between the thalamus and caudate. Septal veins drain the septum pellucidum and join the thalamostriate veins to form paired internal cerebral veins. The choroid plexus of the lateral ventricles runs from the foramina of Monro posteriorly, coursing medial to the thalami, and arcing into the atria of both ventricles along the choroidal fissure. (Image courtesy of AL Rhoton, Jr.)