Lecture 22. Thalamus and Diencephalon 2025

What are the four parts of the diencephalon?

Epithalamus, Thalamus, Subthalamus, Hypothalamus

What is the primary function of the thalamus?

Relay sensory information and assist in regulating motor function.

What is the role of the habenular nuclei?

Function as a relay station for afferent olfactory signals and projects to influence the reticular formation.

What does the pineal gland produce?

Melatonin, which modulates sleep-wake cycles.

Which thalamic nucleus is associated with the visual system?

Lateral Geniculate Nucleus (LGN).

What is the function of the Ventral Posterolateral (VPL) nucleus?

Receives sensory information from the neck and below and projects to the primary somatosensory cortex.

What could a lesion in the Ventral Anterior (VA) nucleus affect?

Planning and initiating movements.

How does the thalamus interact with the cerebral cortex?

Through reciprocal connections via four thalamic peduncles incorporated into the corona radiata.

What is the function of the medial geniculate nucleus (MGN)?

Receives auditory fibers and projects to the primary auditory cortex for perception of hearing.

What is the significance of the internal medullary lamina in the thalamus?

It is a Y-shaped band of white matter that separates the thalamic nuclei into clusters.

Which thalamic nucleus is involved in attention and arousal?

Centromedian nucleus.

What happens when there is a lesion to the Pulvinar nucleus?

It can result in visual attention disorders.

What modulates the circadian rhythms in the brain?

The epithalamus, particularly through the pineal gland.

Which nuclei are classified as specific relay nuclei?

Ventral posterolateral (VPL) and ventral posteromedial (VPM) nuclei.

What are the primary arterioles supplying the thalamus?

Tuberal arteries from the posterior communicating artery, thalamoperforating arteries from the posterior cerebral artery, and others.