Intro | Amygdala | Brainstem | Cerebellum | Cerebrum | Corpus Callosum | Reticular Formation | Hippocampus | Hypothalamus | Medulla | Pituitary Gland | Pons | Spinal Cord | Thalamus
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test
Part 3: Multiple-Choice Self-Test
The Brainstem forms a large portion of the hindbrain. The medulla, pons, and reticular formation are important regions found within the brainstem. The spinal cord is found at the lower junction of the brain stem, beginning at the lumbar region of the vertebral column and ending deep within the brain, which blossoms like a flower above it.
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The complete brain stem is a large region that includes the medulla, pons, and cerebellum (hindbrain structures), the midbrain, and the hypothalamus and thalamus (forebrain structures). These structures in the human are equivalent to the brainstem found in primitive premammalian organisms. Since eating behaviors were present in less evolved organisms, it was expected that basic eating behaviors such as chewing and swallowing would be controlled in some fashion by lower brain regions. Indeed, studies have shown that animals whose brain stems are cut off from the cerebrum, between the thalamus and the midbrain, are able to perform these eating behaviors when the food is placed before them in liquid form. These animals can distinguish between sweet and bitter tastes, swallowing the former and spitting out the latter. They even respond to cues of hunger by drinking more when deprived of food for 24 hours.