Diencephalon, Thalamus, and Hypothalamus Neuroanatomy

Vocabulary flashcards reviewing key anatomical structures, connections, limits, and functions of the diencephalon, thalamus, subthalamus, hypothalamus, and hypophysis.

Diencephalon Boundaries

Anatomical region extending from the interventricular foramen to the imaginary boundary of the anterior border of the superior colliculus, surrounding a large portion of the third ventricle.

Habenular Trigone and Habenular Sulcus

Anatomical landmarks formed at the junction of the habenula and thalamus; the trigone is an enlargement and the sulcus is a depression situated between this enlargement and the pulvinar.

Habenulo-interpeduncular Tract

A neural tract that directly connects the habenula with the interpeduncular nuclei.

Thalamus

A structure composed of gray matter neuronal nuclei interspersed with white matter nerve fibers that acts as a relay station for major sensory systems (excluding olfactory) and integrates visceral and somatic functions with the cerebral cortex.

Thalamic Association Nuclei

Thalamic nuclei that receive most of their input from the cerebral cortex itself and project back to cortical association areas.

Non-specific Thalamic Nuclei

Group of thalamic nuclei that includes the reticular nucleus, intralaminar nuclei, and midline nuclei (excluding specific nuclei like the anterior nucleus).

Ventral Posterior Lateral Nucleus

A thalamic nucleus that receives afferent fiber inputs from both the cerebellum and the motor cortex.

Thalamic Radiations

White matter nerve fibers that originate in the thalamus and project toward various areas of the cerebral cortex.

Ventral Anterior Nucleus

A thalamic nucleus responsible for conveying signals from the basal ganglia to the premotor cortex to plan and initiate movements.

Internal Medullary Lamina

A Y-shaped white matter structure in the thalamus that separates the medial portion from the lateral portion and surrounds the anterior thalamic nuclei.

Fields of Perizonal Nuclei

Nuclei located around the zona incerta in the subthalamic region.

Subthalamic Nucleus of Luys

An anatomical nucleus situated between the inferior end of the internal capsule and the zona incerta.

Limbic Nuclei of the Mammillary Body

The lateral and medial nuclei of the mammillary body located within the posterior hypothalamic area.

Dorsal Supraoptic Commissure

A decussation of afferent fibers originating from the pons and midbrain, located directly above the optic chiasm.

Main Pituitary Vascularization

The primary blood supply system of the pituitary gland formed by the superior and inferior hypophyseal arteries, hypophyseal portal veins, and efferent peri-hypophyseal veins.

Posterior Pituitary Innervation

Nerve fibers innervating the posterior lobe of the hypophysis that originate from the supraoptic and paraventricular nuclei of the hypothalamus.

Main Function of the Neurohypophysis

To store hormones produced by hypothalamic nuclei.

Reticular Nucleus of the Thalamus

A nucleus extending from the rostral pole to the pulvinar and lateral geniculate nucleus between the external medullary lamina and internal capsule, which is unique for not projecting to the cerebral cortex.

Infundibulum

Also known as the pituitary stalk, it is the structure that emerges in a posterior and superior direction from the neurohypophysis.

Tuber Cinereum

A hypothalamic structure that features a median projection known as the median eminence.

Motor Connections of the Subthalamus

Main subthalamic pathways involved in motor control that link with the substantia nigra, red nuclei, and globus pallidus.