Brain stem

An evolutionary older, more ‘primitive’ part of the lower central mammalian brain responsible for organizing fundamental emotions related to fear, hunger, sex, protective drives and temperature control, emotionality, arousal, sleep, heart and breathing rates, water retention, blood pressure and volume, as well as possibly the ratio of carbon dioxide to oxygen.  Among other functions, it also involved in the control of eye movements via the horizontal and vertical ‘gaze centers’ situated there.  Its three main structures are the pons, medulla, and reticular system (see figure below). 

Brain stem, to which the cerebellum is attached by means of peduncles, showing its three main structures: pons, medulla and reticular formation.

See Anencephaly, Apnea, Arcuate nucleus, Cell migration, Cerebral cortex (development), Cerebellum (development), Chiari II malformation, Cochlear nucleus, Corticobulbar tract (CBT), Cranial nerves, Diencephalon, Entorhinal cortex, Locus coeruleus (or ceruleus), Medulla oblongata, Mesencephalic reticular activating system, Mesencephalon, Metabolism, Myelination, Neuronal migration disorders, Orbitofrontal cortex, Pons, Raphe nuclei, Superior colliculus