Medulla Oblongata Transverse Sections: Key Structures at Decussation Levels

Medulla Oblongata Transverse Sections: Key Structures at Decussation Levels

Question 1. Enumerate the main structures seen in the transverse section of the medulla oblongata at the level of the pyramidal decussation.

Answer. The main structures seen in the transverse section of the medulla oblongata at the level of the pyramidal decussation are as follows:

• Decussation of pyramidal tracts
• Appearance of nucleus gracilis and nucleus cuneatus
• Formation of the nucleus of the spinal tract of the trigeminal nerve

medulla oblongata transverse section

• Appearance of the reticular formation
• Detachment of the anterior horns due to the decussation of the pyramidal tracts

Question 2. Enumerate the main structures seen in the transverse section of the medulla oblongata at the level of sensory decussation.

Answer. The main structures seen in the transverse section of the medulla oblongata at the level of sensory decussation are as follows:

• Sensory decussation (decussation of arcuate fibres)
• Formation of medial lemnisci
• Formation of nucleus gracilis and nucleus cuneatus
• Formation of the nucleus of the spinal tract of the trigeminal nerve

pyramidal decussation

• The appearance of the accessory cuneate nucleus
• Formation of central grey matter and nuclei within it (Example: hypoglossal nucleus, dorsal nucleus of vagus, and nucleus tractus solitarius)
• Appearance of the inferior olivary nucleus