Subcortical Structures And Their Functions Flashcards
What is the basal nuclei?
A collection of nuclei deep to the white matter of the cerebral cortex.
What is the basal nuclei composed of?
Caudate nucleus
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra
What is the striatum made up of?
The caudate nucleus and the putamen
What is the globus pallidus?
It can be subdivided into:
- globus pallidus externa (Gpe)
- globus pallidus interna (Gpi)
Output nucleus of basal nuclei
Both parts are functionally different with different connections
What is the lentiform nucleus made up from?
Globus pallidus and the putamen
How does the subthalamic nucleus act as part of the basal nuclei?
Receives afferents from the cortex and other basal nuclei structures
Excitatory output to globus pallidus and substantia nigra
Where is the substantia nigra found?
In the rostral midbrain
Dopaminergic neurons project to striatum and subthalamic nucleus
What are the four main parts of the limbic system?
Cingulate gyrus
Septal nuclei
Hippocampus
Amygdala
Where is the limbic system found?
A ring of cortex spanning frontal, parietal and temporal lobes.
What structures are part of the limbic system?
Subcallosal gyrus
Cingulate gyrus
Parahippocampal gyrus
Hippocampal formation
Amygdaloid nucleus mammillary
Anterior thalamic nucleus
What are the three main parts to the hippocampus?
Subiculum
Hippocampus proper
Dentate gyrus
What is neuro genesis?
The process in which neurones are generated from stem cells in the adults, the growth and development of nervous tissue.
What afferents are involved in the amygdala?
Visual
Somatosensory
Gustatory
Olfactory
Thalamic
Cortical
What roles does the amygdala have?
Emotions
Emotional memory and learning
Fear
Reward
If damaged normal facilitation of attention and memory of emotional stimuli is affected
Where is the Diencephalon found?
Between the brain stem and the cerebral hemisphere.
List the features of the thalamus.
2 thalami, one on each side of the 3rd ventricle
Connected by inter thalamic connection
Received and processes all info coming to the cerebrum
Subcortical structures project to the cortex via thalamus
Mediates emotional response, arousal and emotion
Name the sensory relay nuclei found in the thalamus.
VPL - ventral posterolateral (spinothalamic)
VPM - ventral posteromedial (trigeminal)
MGN - medial geniculate nucleus (cochlea)
LGN - lateral geniculate nucleus (retina)
Name the motor relay nuclei found in the thalamus.
VA - ventral anterior nucleus
VL - ventral lateral nucleus
Name the two limbic relay nuclei in the thalamus.
Anterior nucleus (ANT)
Lateral dorsal nucleus (LD)
Describe the anterior nucleus.
Input from ipsilateral mammillary body, relayed to cingulate cortex and prefrontal and parietal cortices
Describe the lateral dorsal nucleus.
Input from entorhinal cortex relayed to cingulate cortex and prefrontal and parietal cortices
What do the association nuclei do within the thalamus?
Modulators in interactions of one part of the cortex with another
Name the two association nuclei within the thalamus.
Pulvinar
Dorsomedial
Describe the pulvinar nucleus.
Receives input from retina and visual association areas to integrate and evaluate.
Visuospatial working memory
Related to auditory processing coordinates and engages areas important in language
Describe the dorsomedial nucleus.
Afferent fibres from basal nuclei and amygdala
Plays a roles in limbic circuit of motivational and emotional aspects of behaviour
Which nuclei are found in the thalamus?
Intralaminar nuclei
Thalamic reticular nucleus
What two nuclei make up the intralaminar nuclei?
Centromedian (CM)
Parafasicular (PF)
What do the intralaminar nuclei do?
Play a role in arousal and in facilitating awareness and vigilance
Connections to the striatum suggest a role in facilitating goal orientated behaviour
Where is the thalamic reticular nucleus found and what does it do?
Sheet of neurones surrounding the thalamus
Modulate excitatory projections between the thalamus and cortex
Influence the flow of information from the thalamus
Where is the hypothalamus found?
The floor of the Diencephalon
It is attached to the pituitary gland at the central side by the infundibulum and is penetrated by the 3rd ventricle
What is the general role of the hypothalamus?
Main homeostatic centre
Direct contact with blood
Monitors everything
Secretes hormones
What nuclei are found in the hypothalamus?
Supraoptic
Paraventricular
Ventromedial
Suprachiasmatic
Dorsomedial
Arcuate
Tuberal
What are the afferent connections of the hypothalamus?
General somatic, visceral and gustatory
Limbic system
Olfactory information
Thalamohypothalamic
Retinohypothalamic
What are the efferent connections of the hypothalamus?
Descending to visceral motor and nuclei via brainstem and spinal cord
(Sympathetic and parasympathetic nuclei and ganglia)
Ascending to the thalamus
Where is the epithalamus found?
Forms the roof of the Diencephalon
What are the components of the epithalamus?
The pineal gland (circadian rhythms)
Hebenular nucleus
What is the role of the herbenular nucleus?
Centre for integration for olfactory, visceral and somatic efferent pathways
