The rhombencephalon (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates.

The rhombencephalon can be subdivided in a variable number of transversal swellings called rhombomeres. In the human embryo we can distinguish eight rhombomeres, from caudal to rostral: Rh7-Rh1 and the isthmus (the most rostral rhombomere).

Myelencephalon

---

Rhombomeres Rh7-Rh4 form the myelencephalon.

The myelencephalon forms the medulla in the adult brain; it contains:

• a portion of the fourth ventricle,
• the glossopharyngeal nerve (CN IX),
• vagus nerve (CN X),
• accessory nerve (CN XI),
• hypoglossal nerve (CN XII),
• and a portion of the vestibulocochlear nerve (CN VIII).

Metencephalon

---

Rhombomeres Rh3-Rh1 form the metencephalon.

The metencephalon is composed of the pons and the cerebellum; it contains:

• a portion of the fourth ventricle,
• the trigeminal nerve (CN V),
• abducens nerve (CN VI),
• facial nerve (CN VII),
• and a portion of the vestibulocochlear nerve (CN VIII).

Neuroanatomy | Brainstem | Central nervous system | Cranial nerves | Developmental biology

Rhombencephalon | Rombencéfalo | Rhombencephalon | Задний мозг