Human brainstem - anterior view

1. Nervus opticus
2. Chiasma opticum
3. Tractus opticus
4. Infundibulum hypophysialis
5. Corpora mamillaria
6. Fossa interpeduncularis
7. Pons
8. Sulcus basilaris (-> Arteria basilaris)
9. Sulcus pontinus inferior (CN. VI, VII, VIII)
10. Pyramis medullae oblongatae
11. Medulla oblongata, Fissura mediana anterior
12. Sulcus anterolateralis (Fila radicularia nervi cervicalis [C1], CN. XII)
13. Oliva
14. Sulcus retroolivaris (CN. IX, X)
15. Plexus choroideus ventriculi quarti
16. Decussatio pyramidum
17. Substantia perforata anterior
18. Tractus olfactorius

In the Medulla, the right & left Pyramids are separated by the Anterior Median Fissure. The Pyramidal Decussation , where the Pyramidal Tract crosses to the contralateral side, is apparent on the surface of the caudal pyramids. The Olive is a large bump located just lateral to the pyramids in the rostral medulla. A tuft of Choroid Plexus can be seen extending from the Inferior Medullary Velum through the lateral aperture of the 4th ventricle.

In the Medulla, the Preolivary Sulcus is seen between the pyramid and the olive. The Postolivary Sulcus is located between the olive and the Tuberculum Cinereum (not shown). The Inferior Pontine Sulcus is located between the medulla and pons. In the Pons, the Basilar Sulcus or groove of the Basilar artery can be seen.