| Figure 16a: | Forebrain | Hindbrain | Midbrain |
| Figure 16b: | Cerebellum | Medulla | Pons | Reticular Formation | Thalamus |
Part 1: Image-Mapped Tutorial
Part 2: Matching Self-Test:
16a |
16b
Part 3: Multiple-Choice Self-Test
The Forebrain is the most evolved and complex of the brain divisions. It is the most prominent and anterior portion (toward the front). It is also superior (above) the less evolved divisions. The forebrain is also referred to by the Greek name, prosencephalon; which means literally, forward brain. The prosencephalon is further broken down into the telencephalon (consisting of cerebral cortex, hippocampus, basal ganglia, and some portions of the limbic system) and the diencephalon (consisting of the thalamus, pituitary gland, optic chiasm, and the mammillary bodies and hypothalamus of the limbic system). Both appearance and function distinguish the forebrain structures. Each is involved in the complex processes that underlie human thought, emotion, and behavior. They will be covered in more detail in upcoming tutorials as noted below.
Beneath the cerebral cortex or covering of the forebrain, lies a set of structures called the basal ganglia and the limbic system. The basal ganglia play an important role in movement, particularly motivated movements linked to thought, and are described in more detail in Tutorial 32 and Tutorial 33. The limbic system is composed of multiple interconnected structures that form a border around the brain stem, including the hippocampus, hypothalamus, amygdala, anterior thalamus, and cingulate gyrus. The limbic system is particularly important for emotional behaviors and memory, and is discussed in greater detail in Tutorial 18, Tutorial 36, and Tutorial 37.
| Advanced |
The early stages of evolution of the forebrain are similar across all mammals, and the hippocampal formation appears early in the development of the forebrain (Parent, 1996). The characteristic organization of neuronal cell layers as found in the adult human hippocampus, however, are not seen until late in embryonic development. Using the embryonic perspective, the hippocampal formation and related dentate gyrus are grouped together as the archipallium - the most phylogenetically primitive region of the cortex. The archipallium is the most undifferentiated region of the cortex, but is more evolved than the midbrain, the least differentiated region of brain. There are species differences in midbrain structure and function, the most primitive of brain regions, but cross-species differences in structure-function relationships are greater for the hippocampal formation.
| Reference |
Parent, A. (1996). Carpenter's human neuroanatomy (9th ed.). London: Williams & Wilkins.