Diencephalon Flashcards
What are the Anatomical Components of the Diencephalon?
Thalamus
Epithalamus
Subthalamus
Hypothalamus
Thalamus Functions (4)
- Processes sensory inputs
- Relays sensory inputs selectively to areas in the cerebral cortex
- Regulates sleep and consciousness
- Provides sensory feedback to the motor system, basal ganglia, & cerebellum
70-80% of humans have an interthalamic adhesion called?
Massa Intermedia
What divides the thalamus?
Internal Medullary Lamina
How many Major Subdivisions of the Thalamus, what are they?
- Anterior Region
- Ventro Lateral Region
- Medial Region
- Posterior Region (Pulvinar)
[Anterior Thalamic Nuclei]
How many nuclei does it have?
Function?
Where does it receive major input from?
Only One
Uncertain Role, probably with emotions and memory
Receives input from
- Mammillary Nuclei of Hypothalamus
- Presubiculum of the Hippocampal Formation
[Medial Thalamic Nuclei]
How many subdivisions
Where does it receive inputs?
Function?
3 Subdivisions, each with connections to parts of the frontal cortex
Receives inputs from:
- Portions of the Basal Ganglia
- Amygdala
- Midbrain
Memory
How many ventral nuclei are there?
Names?
3
Ventral Anterior Nucleus
Ventral Lateral Nucleus
Ventral Posterior Nucleus
Where does the Ventral Lateral Nucleus receive inputs?
Substantia Nigra
Globus Pallidus
Cerebellum
Where does the Ventral Lateral Nucleus send inputs?
Primary motor cortex and premotor cortex
Function: Ventral Lateral Nucleus
Learning of movements
Where does the Ventral Anterior Nucleus receive inputs?
Substantia Nigra
Globus Pallidus
Where does the Ventral Anterior Nucleus send inputs?
Supplementary Motor Cortex
Function: Ventral Anterior Nucleus
Planning movements
Initiates wanted movements
Inhibits unwanted movements
Where does the Ventral Postero-Medial Nucleus receive inputs?
Solitary Tract
Trigeminal nerve via Trigeminal Lemniscus and Trigeminothalamic Tract
Function: Medial Geniculate Nucleus
Relays auditory impulses from inferior colliculus to auditory cortex
Function: Lateral Geniculate Nucleus
Processes visual inputs from retina via the optic nerve
Sends projections to the primary visual cortex via the optic radiations (geniculo-calcarine/geniculostriate pathway)
What is the most posterior nucleus of the Thalamus?
Pulvinar
4 Subnuclei of the Pulvinar and Where they Project
Lateral :: visual cortical association areas
Inferior :: visual cortical association areas
Oral :: somatosensory cortical association areas
Medial :: cingulate, posterior parietal & prefrontal cortices

Parts of the Epithalamus (3)
Habenula
Stria Medullaris
Pineal Gland
Other name for Pineal Gland
Epiphysis
Function: Pineal Gland
Produces Melatonin
Parts of Subthalamus (4)
Subthalamic Nucleus of Luys
Zona Incerta
Reticular Nucleus of the Thalamus
Fields of Forel
Parts of Hypothalamus (3)
Hypothalamus
Pituitary Gland
Mammillary Body
Hypothalamic Boundaries:
Anterior
Posterior
Superior
Inferior
Anterior – Optic chiasm & anterior commissure
Posterior – Mammillary bodies
Superior – Hypothalamic sulci
Inferior – Hypophysis
