DIENCEPHALUS = intermediate brain

Location

In the extension of the brainstem, under the cerebral hemispheres. Contains ventricle III.

External configuration

It has 2 sides:

• basal with optic chiasm, optic tracts, pituitary, thalamus, metatalamus, hypothalamus
• posterior, covered by EC with epiphysis, epitalamus and thalamus

Internal configuration

The 5 masses of nerve substance are made up of gray and white matter

• Thalamus oval
• The metatalamus (meta = after) consists of the 2 medial and lateral geniculate bodies, located behind the thalamus. CGM - acoustic relay station and CGL - visual relay station.
• Epitalamus (epi = above) - located on the posterior face of the diencephalon, above the thalamus, posterior to the ventricle III. - consisting of the epiphyseal gland and 2 habenular nuclei with a role in coordinating the secretory and motor digestive reflexes and the olfactory-somatic reflexes (turning the head after smell) coordinated by the epiphyseal gland. - acts on the hypothalamic-pituitary complex through the epiphysis that is part of the epitalamus.
• Hypothalamus (hypo = under the thalamus) = vegetative brain and pituitary = endocrine brain (this link integrates nerve activity with endocrine activity ). Both structures are under the control of the prefrontal area - the association neocortex.