Diencephalon
The diencephalon
- The thalamus, metathalamus, subthalamus, hypothalamus, and epithalamus.
- Thalamic nuclei
- Thalamic fiber tracts
Metathalamus
Subthalamus
- Subthalamic nucleus
- Zona incerta
- Fields of Forel
- Hypothalamic nuclei
- Hypothalamic fiber tracts
- Mammillary bodies
- Neurohypophysis (the posterior lobe of the pituitary body)
- Neural lobe
- Infundibulum
Epithalamus
- Habenula
- Pineal gland
- Pretectal area
- Pretectal nuclei
- Posterior commissure
- Subcommissural organ
Major white matter bundles that pass through the diencephalon
- The column of the fornix
- Descends through the hypothalamus and connects with the mammillary bodies.
- Stria medullaris thalami
- Passes from the habenula along the dorsomedial thalamus to the septal nuclei, which lie above the anterior commissure (they are part of the limbic system).
- The anterior, posterior, and habenular commissures.
Hypothalamic Anatomy
- Lamina terminalis
- The anterior border of the hypothalamus (it separates the hypothalamus from the subcallosal region of the limbic lobe and it is variably considered either a diencephalic or telencephalic structure and spans from the anterior commissure, superiorly, to the optic chiasm, inferiorly).
- Tuber cinereum
- The inferior border of the hypothalamus (ends, posteriorly, at the mammillary bodies).
- Median eminence of the infundibulum (the pituitary stalk): antero-inferior.
- The funnel-shaped dip in the tuber cinereum. Attach the pituitary gland to the infundibulum.
- Neural lobe (pituitary gland, posterior).
- Neurally connected to the hypothalamus via the hypothalamohypophysial tract.
- Adenohypophysis (anterior lobe of the pituitary gland).
- Forms from Rathke's pouch: an outgrowth of the roof of the mouth, and therefore, it is not a diencephalic structure. The adenohypophysis is linked to the hypothalamus via the hypothalamohypophysial venous portal system.
Central diencephalon - coronal view
- Superiorly, lies the thalamus.
- Ventrolateral to it, lies the subthalamus.
- Ventromedial to it, lies the lateral wall of the third ventricle.
- The hypothalamus and include its infero-lying mammillary bodies.
- The supramammillary commissure stretches across midline above the mammillary bodies.