Rhombencephalon

The rhombencephalon, or hindbrain, is the posterior primary vesicle of the developing vertebrate brain. In early embryogenesis this region gives rise to the brainstem and cerebellum, and its proper patterning is essential for autonomic and motor function.

During the early weeks of development the rhombencephalon divides to form two secondary vesicles: the metencephalon and the myelencephalon. The metencephalon develops into the pons and the cerebellum, while the myelencephalon forms the medulla oblongata. The rhombencephalon also produces the fourth ventricle, a chamber within the brainstem filled with cerebrospinal fluid. The hindbrain is segmented into rhombomeres, repeating units that help organize cranial nerve development and neural connectivity.

In the adult nervous system, structures derived from the rhombencephalon include the brainstem (medulla oblongata and pons) and the cerebellum. These regions regulate vital autonomic processes, posture and balance, and complex motor coordination. Blood supply to the hindbrain arises mainly from branches of the vertebral and basilar arteries.

Clinical relevance: malformations or injuries affecting the rhombencephalon during development can lead to disorders of balance, coordination, respiration, and other autonomic functions.