Slide 28: Pontomedullary Junction

Identify:

• Pyramidal Tract (PT)
• Medial Lemniscus (ML)
• Tectospinal Tract (TST)
• Medial Longitudinal Fasciculus (MLF)
• Superior Vestibular Nucleus (SVN)
• Inferior Cerebellar Peduncle (ICP)
• Principal Olive IPO)
• Spinal Trigeminal Tract and Nucleus (SpTTrN)
• Superior Cerebellar Peduncle (SCP)
• Abducens Nucleus (6)
• Genu of the Facial Nerve
• Facial Motor Nucleus (7)
• Superior Vestibular Nucleus (SVN)

Note:

• The "bump" formed in the floor of the Fourth Ventricle by the abducens nucleus and the genu of the facial nerve is called the Facial Colliculus.
• Note the olivocerebellar fibers crossing and entering the cerebellum via the ICP.
• The Facial Nerve is concerned with:
• Facial Motor Nucleus - SVE (muscles of facial expression)
• Solitary Nucleus - GVA and SVA (anterior 2/3 of tongue)
• Spinal Trigeminal Nucleus - GSA (portion of external ear)
• Superior Salvitory Nucleus - GVE (lacrimal, submandibular, and sublingual glands)