Thalamus Flashcards
What does Diencephalon give rise to
Thalamus, Subthalamus, Hypothalamus
describe structure of thalamus
Split down the middle by third ventricle
Ventral to the lateral ventricles
Organised into discrete nuclei
describe functions of thalamus
It’s a relay centre between the cerebral cortex and rest of CNS – two way connection
Thalamus also integrates and modifies info as it passes through
Nuclei in thalmus for virtually every functional system
which functional system does the thalamus not have nuclei for
olfaction (smell)
Name 2 thalmic nuclei whcih form RAS
Intralaminar Nuclei
Reticular nucleus
Describe function of Intralaminar nuclei (and neuron type)
Project to various medial temporal lobe structures
Mostly Glutamatergic neurons - excitatory
which structures do intralaminar nuclei project to
Amygdala = emotions, fear, anxiety
Hippocampus = memory
Basal ganglia = movement
(all in temporal lobe)
Describe function of reticular nucleus (and neuron type)
forms outer covering of the thalamus
Influences flow of information through the other nuclei to the cortex
mainly GABAergic – inhibitory
What is distinguishes reticular nucleus from other nuclei
no distal connections just intrathalamic connections
What is function of RAS
(Reticular activating system)
RAS is the system that maintains consciousness
Intralaminar and Reticular nuclei offer direct and indirect way of controlling activity of nucleus
what is ascending reticular activating
Reticular formation projects up to the thalamus
The greater the activity through RF the…….
more stimulated the cortex becomes – translates into consciousness/awareness
what is reticular formation
set of interconnected pathways in brainstem
where are inputs from ARAS recieved
Both intralaminar and reticular nucleus
Hypothalamus structure
Lies below thalamus – divided down the middle
by 3rd ventricle
Collection of individual nuclei with distinct functions
