Exam 2- week 7 ppt 8 Diencephalon: Thalamus Flashcards
What are 4 major subdivisions of the diencephalon?
~thalamus
~hypothalamus
~epithalamus
~subthalamus
Quick info on hypothalamus
endocrine, autonomic, and limbic functions
Quick info on thalamus
centrally located relay and association nuclei
Quick info on epithalamus
pineal gland and associated structures
Quick info on subthalamus
one of the basal nuclei (ganglia)
thalamus has relations to
~subthalamus
~red nucleus
~substantia nigra
~zona incerta
Where are the subthalamus, red nucleus and substantia nigra located in relation to the thalamus?
all postero-inferior to the thalamus
Where is the zona incertra in relation to the thalamus?
~contiguous with a part of the thalamus – a nucleus called the thalamic reticular nucleus
~also inferior to the thalamus
the thalamus has ______ nuclei and _____ nuclei
~sensory relay nuclei
~motor relay nuclei
Sensory relay nuclei of the thalamus
~All sensory pathways except olfaction relay in thalamus prior to entering cerebral cortex
~Located in posterior (caudal) thalamic nuclei
Motor relay nuclei of the thalamus
~Way for basal nuclei (ganglia) & cerebellum to communicate with cerebral cortex
~Located in anterior (rostral) thalamic nuclei
The nuclei are topographically organized into _ regions by
into 3 regions or sets of nuclei by sheets of myelinated axons that form internal medullary lamina
What are the 3 major regions for the nuclei?
~anterior nuclei
~lateral nuclei
~medial nuclei
Medial nuclei of the thalamus
~Dominated by dorso-medial nucleus (DM)
~Midline nuclei which line ventricular surface
Lateral nuclei of the thalamus
~composed of a Dorsal tier and a Ventral tier
Dorsal lateral nuclei of the thalamus
include:
~Lateral dorsal
~Lateral posterior
~Pulvinar (the large posterior positioned nucleus)
Ventral lateral nuclei of the thalamus
consist of:
~Ventral anterior (VA)
~Ventral lateral (VL)
~Ventral posterior (VP)
Ventral posterior nucleus is composed of two separate nuclei ~Ventral Posterior Lateral (VPL) ~Ventral posteror Medial (VPM) nuclei. ~Lateral geniculate body (or nucleus) ~Medial geniculate body (or nucleus)
Two other nuclei in the thalamus
~interlaminar nuclei
~reticular nuclei
Interlaminar nuclei of the thalamus
~within the Internal medullary lamina splits the thalamus dorsally & ventrally
~Centromedian nucleus is ventrally positioned
~lateral dorsal nucleus is dorsally positioned
~small interlaminar nuclei in between the two larger nuclei
Reticular nucleus of the thalamus
~located external to the thalamus – just medial to internal capsule
~plays an important role in regulating the excitability of other thalamic nuclei