Question

What are the most caudal transverse divisions of the brainstem and where are they located?

1) Mesencephalon, above the medulla oblongata
2) Myelencephalon, below the mesencephalon
3) Metencephalon, above the pons
4) Mesencephalon, above the spinal cord and the foramen magnum

Answer 1

The most caudal transverse divisions of the brainstem are the myelencephalon (medulla oblongata) and the metencephalon (pons and cerebellum), with the myelencephalon being located below the mesencephalon.

Step-by-step explanation:

The most caudal transverse divisions of the brainstem are the myelencephalon, which corresponds to the adult structure known as the medulla oblongata, and the metencephalon, which gives rise to the pons and the cerebellum. The myelencephalon is located below the mesencephalon (midbrain). It's important to note that the mesencephalon is not the most caudal but actually sits above the medulla oblongata, making options 1 and 4 incorrect. The metencephalon is above the myelencephalon but is still considered part of the brainstem and not above the pons as option 3 mistakenly suggests. Therefore, the correct answer is option 2) Myelencephalon, below the mesencephalon.