Human caudal brainstem - posterior view

1. Sulcus medianus
2. Eminentia medialis
3. Colliculus facialis (Motor fibers of VII passing over Motor Nucleus of VI)
4. Area vestibularis
5. Area auditoria (Nucleus cochlearis dorsalis)
6. Trigonum nervi hypoglossi
7. Trigonum nervi vagi
8. Area postrema
9. Obex
10. Sulcus posterolateralis
11. Sulcus intermedius posterior
12. Sulcus medianus
13. Fasciculus gracilis
14. Tuberculum gracile (Nucleus gracilis)
15. Fasciculus cuneatus
16. Tuberculum cuneatum (Nucleus cuneatus)
17. Funiculus lateralis medullae oblongatae
18. Apertura lateralis ventriculi quarti

In the caudal Medulla, several structures are seen. The Posterior Median Sulcus is on the midline. The Posterior Intermediate sulcus divides the Fasciculus Gacilis (long & slender) and Fasciculus Cuneatus (wedge shaped), and the Posterolateral Sulcus separates the Fasciculus Cuneatus from the more lateral swelling, the Tuberculum Cinereum (Spinal Nucleus of V). The Fasciculus Gracilis terminates rostrally in a swelling - the Tuberculum (Nucleus) Gracilis and the Fasciculus Cuneatus terminates in the Tuberculum (Nucleus) Cuneatus.

A swelling on either side of the Posterior Median Sulcus called the Median Eminence is present from the rostral medulla through the pons. In the caudal pons a small rounded elevation in the median eminence, the Facial Colliculus (Motor fibers of VII passing over the Nu of VI ) can be seen.

Lateral to the median eminence at the junction between the medulla & pons is the Vestibular Area (Vestibular Nuclei), and lateral to this is the Auditory Area (Dorsal Cochlear Nucleus). The Sulcus Limitans separates the Median Eminence from the Vestibular Area.

Three V-shaped swellings can be seen in the caudal portion of the fossa. These are from medial to lateral: Hypoglossal Trigone (Motor Nu XII), Vagal Trigone (Dorsal Motor Nu X), Area Postrema (Emetic Center).

Rostral to the tuberculum gracilis is the floor of the 4th ventricle or Rhomboid Fossa which extends from the mid-medulla to the mid to rostral Pons. The caudal most point of the ventricle is called the Obex.