neuri ch 5 part 1

Vocabulary flashcards covering the diencephalon, thalamus, thalamic nuclei, and related structures as described in the lecture notes.

The brain region comprising the thalamus, hypothalamus, epithalamus, subthalamus, and optic tract; paired structures derived from the prosencephalon, interconnected with CNS regions to support cognition, language, sensation, motor control, and homeostasis.

Diencephalon

Largest diencephalic structure that relays and integrates sensory and motor information; acts as a gatekeeper for most sensory pathways (except olfaction) and engages in cognitive functions via widespread cortical and subcortical connections.

Thalamus

A bridge of tissue connecting the two thalami through the third ventricle; present in about 75% of people; function is not clearly understood.

Massa intermedia (thalamic adhesion)

A Y-shaped sheet of white matter within the thalamus that separates nuclei and houses some intralaminar nuclei.

Internal medullary lamina

Group of thalamic nuclei embedded in the internal medullary lamina; involved in arousal and diffuse cortical activation.

Intralaminar nuclei

Specific nuclei have bidirectional connections to particular cortical areas; nonspecific nuclei connect with brainstem arousal systems and have no direct cortical connections.

Specific vs nonspecific thalamic nuclei

Medial thalamic complex densely connected with prefrontal/orbitofrontal cortices, hippocampus, and limbic system; implicated in mood, emotion, cognition, personality, memory, and language.

Mediodorsal (MD) nucleus

Anterior thalamic nucleus with strong connections to the hippocampus, frontal lobes, and cingulate gyrus; important for memory and influences emotion and executive function.

Anterior (Ant) nucleus

Lateral nuclear group involved in complex sensory integration and visceral/sensory information processing; connections to parietal association areas.

Lateral dorsal (LD) and lateral posterior (LP) nuclei

Ventral motor-related nuclei; connect with globus pallidus, substantia nigra, primary motor cortex, and cerebellum to aid motor integration and coordination.

Ventral lateral (VL) and ventroanterior (VA) nuclei

Somatosensory relay nuclei; VPL receives body signals from spinal nerves, VPM from head/neck via cranial nerves; both project to the primary somatosensory cortex (S1).

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

Thalamic nucleus involved in language and vision; connections to superior colliculus and angular/marginal gyri.

Pulvinar (P)

Auditory relay nucleus; receives input from inferior colliculus/brainstem and projects to the auditory cortex.

Medial geniculate nucleus (MGN)

Visual relay nucleus; receives input from the optic nerve and projects to the primary visual cortex.

Lateral geniculate nucleus (LGN)

Diencephalic region including structures like the pineal gland; involved in circadian and limbic system functions.

Epithalamus

Endocrine gland producing melatonin; regulates circadian rhythms and sleep–wake cycles.

Pineal gland

White matter pathway carrying visual information from the optic chiasm toward the thalamus (LGN) and other visual processing areas; included among diencephalic structures in the notes.

Optic tract

Subcortical structure coordinating autonomic and endocrine functions; integrates visceral information with emotion and behavior; a key regulator of homeostasis.

Hypothalamus

Master endocrine gland controlled by the hypothalamus; secretes hormones that regulate growth, metabolism, and reproduction.

Pituitary gland

Reciprocal, reverberating circuit between cortex and thalamus that supports sustained cortical activation and communication.

Thalamo-cortico-thalamic loop

Self-sustaining neural loop in which axon collaterals repeatedly stimulate the same neurons, contributing to persistent activity.

Reverberating circuit