Part of Body: thalamus, lateral ventricle, third ventricle, internal capsule
Orientation of Section: transverse
Number of Sections: 1
Stained with: weigert method

Section through the third and lateral ventricles, thalamus, internal capsule, etc. of a human brain, stained by the Weigert method. Note first the body of the lateral ventricle (LV); its roof is formed by the corpus callosum (CC) and its floor by the thalamus medially and the caudate nucleus (Cd) laterally.  In the mid-line are seen the columns of the fornix (F’). Now look at the thalamus and identify the following nuclei − the anterior nucleus (A) which receives the termination of the mamillo-thalamic tract and relays impulses to the gyrus cinguli; the lateral nucleus (L) which projects on to the “association areas” of the frontal end parietal cortex; the ventral nucleus (V) which receives the termination of the fillet system and relays to the post-central gyrus; and the medial nucleus (Md) which projects on to the pre-frontal cortex. The mamillo-thalamic tract (Mt) is seen on its way up to the anterior nucleus, and below the fornix column (F") is seen ending in the mamillary body (M).

Now look at the internal capsule, (IC), sandwiched between the thalamus and the lentiform nucleus. Among other fibre systems it contains the pyramidal tract, and below it is continued down into the cerebral peduncle (CP). Above the latter, in the region known as the sub-thalamus, is seen the ansa lenticularis (Al), an important efferent system of fibres from the globus pallidus.

The lentiform nucleus is seen to be divided into two distinct categories, the putamen (P) (containing very few myelinated fibres and similar in structure to the caudate nucleus) and the globus pallidus (G). The latter in permeated by a rich plexus of myelinated fibres. Lastly, below the cerebral peduncle, observe the optic tract, cut across.


Original card