THE DIENCEPHALON AND THE OPTIC NERVE 



217 



medullary lamina bifurcates and includes between its two limbs the anterior 

 nucleus. 



The anterior nucleus (or dorsal nucleus) of the thalamus is located in the 

 dorsal part of the rostral extremity of the thalamus and penetrates like a wedge 

 between the medial and lateral nuclei. It protrudes somewhat above the 

 general level of the dorsal surface, forming the anterior tubercle of the thalamus. 

 It receives a large bundle of fibers from the mammillary body, the mamillotha- 

 lamic tract or bundle of Vicq d'Azyr (Figs. 156, 204, 205), and sends fibers to the 

 caudate nucleus of the corpus striatum (Fig. 196). 



TatHia tecia Stria* Lancisii 



Subitaut'ui nigra 



catidatta 



Nticleta anterior tkalami 

 KucUm lakralis tkalami 

 Nuclrmt miJiafa tkalami 



lint thatamiaa 



nsa lenticularis 



Trattiu oftlcia 

 Pa feduuaiU 



Fig. 156. Frontal section through the mammillary body, thalamus, and adjacent structures. 



Weigert method. (Villiger-Piersol.) 



The medial nucleus of the thalamus is situated between the central gray 

 matter of the third ventricle and the internal medullary lamina, which separates 

 it from the lateral nucleus except in the caudal part, where the line of separation 

 between the two is not distinct. It is said to receive fibers from the olfactory 

 centers and to send fibers to the caudate nucleus and the subthalamus. 



The lateral nucleus of the thalamus is by far the largest of the three. It 

 extends farther caudad than the medial nucleus and includes all of the pulvinar. 

 Through the external medullary lamina and the internal capsule it sends fibers 

 to the cerebral cortex in the thalamic radiation and receives corticothalamic 



